{"collection":"philosophy-ethics","full_text_available":true,"graph_url":"https://unchartedknowledge.5gfusion.net/v2/api/page/gutenberg_66177/graph","html_url":"https://unchartedknowledge.5gfusion.net/v2/page/gutenberg_66177","id":"gutenberg_66177","license":"Public Domain (US)","rights_basis":"gutenberg_metadata_copyright_false","source":"gutenberg","source_url":"https://www.gutenberg.org/ebooks/66177","summary":null,"tags":["Category: Essays, Letters & Speeches","Category: Philosophy & Ethics","Category: Science - Biology","Category: Science - Physics","Science"],"text":"HALF HOURS\n\n                                  WITH\n\n                           MODERN SCIENTISTS.\n\n\n                          LECTURES AND ESSAYS\n\n\n                                   BY\n\n           PROFS. HUXLEY, BARKER, STIRLING, COPE AND TYNDALL.\n\n\n                                  WITH\n\n\n                         A GENERAL INTRODUCTION\n\n\n                                   BY\n\n                       NOAH PORTER, D.D., LL.D.,\n\n                       PRESIDENT OF YALE COLLEGE.\n\n\n\n                             FIRST SERIES.\n\n\n[Illustration]\n\n\n\n                           NEW HAVEN, CONN.:\n                      CHARLES C. CHATFIELD & CO.,\n                                 1872.\n\n\n------------------------------------------------------------------------\n\n\n                      \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n       Entered according to act of Congress, in the year 1872, by\n\n                      CHARLES C. CHATFIELD & CO.,\n\n    In the Office of the Librarian of Congress, at Washington, D. C.\n                      \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n\n\n\n\n    \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n             NEW HAVEN, CONN.:\n    THE COLLEGE COURANT PRINT.\n    \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n\n\n\n\n                           \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n            Electrotyped by E. B. Sheldon, New Haven, Conn.\n\n\n------------------------------------------------------------------------\n\n\n\n\n                               CONTENTS.\n\n            GENERAL INTRODUCTION. BY PREST. PORTER,       v\n\n            ON THE PHYSICAL BASIS OF LIFE.                1\n              PROF. T. H. HUXLEY,\n\n            CORRELATION OF VITAL AND PHYSICAL            37\n              FORCES.\n              PROF. G. F. BARKER, M.D.,\n\n            AS REGARDS PROTOPLASM\u2014REPLY TO HUXLEY.       73\n              JAMES HUTCHISON STIRLING,\n\n            ON THE HYPOTHESIS OF EVOLUTION.             145\n              PROF. E. D. COPE,\n\n            SCIENTIFIC ADDRESSES.\n\n            ON THE METHODS AND TENDENCIES OF            219\n              PHYSICAL INVESTIGATION,\n\n            ON HAZE AND DUST,                           234\n\n            ON THE SCIENTIFIC USE OF THE                247\n              IMAGINATION,\n\n            PROF. JOHN TYNDALL, LL.D., F.R.S.,          217\n\n\n------------------------------------------------------------------------\n\n\n\n\n INTRODUCTION TO THE NEW EDITION OF HALF HOURS WITH MODERN SCIENTISTS.\n\n\nThe title of this Series of Essays\u2014_Half Hours with Modern\nScientists_\u2014suggests a variety of thoughts, some of which may not be\ninappropriate for a brief introduction to a new edition. _Scientist_ is\na modern appellation which has been specially selected to designate a\ndevotee to one or more branches of physical science. Strictly\ninterpreted it might properly be applied to the student of any\ndepartment of knowledge when prosecuted in a scientific method, but for\nconvenience it is limited to the student of some branch of physics. It\nis not thereby conceded that nature, _i.e._, physical or material nature\nis any more legitimately or exclusively the field for scientific\nenquiries than spirit, or that whether the objects of science are\nmaterial or spiritual, the assumptions and processes of science\nthemselves should not be subjected to scientific analysis and\njustification. There are so-called philosophers who adopt both these\nconclusions. There are those who reason and dogmatize as though nature\nwere synonymous with matter, or as though spirit, if there be such an\nessence, must be conceived and explained after the principles and\nanalogies of matter;\u2014others assume that a science of scientific method\ncan be nothing better than the mist or moonshine which they vilify by\nthe name of metaphysics. But unfortunately for such opinions the fact is\nconstantly forced upon the attention of scientists of every description,\nthat the agent by which they examine matter is more than matter, and\nthat this agent, whatever be its substance, asserts its prerogatives to\ndetermine the conceptions which the scientist forms of matter as well as\nto the methods by which he investigates material properties. Even the\npositivist philosopher who not only denounces metaphysics as\nillegitimate, but also contends that the metaphysical era of human\ninquiry, has in the development of scientific progress been outgrown\nlike the measles, which is experienced but once in a life-time; finds\nwhen his positivist theory is brought to the test that positivism itself\nin its very problem and its solutions, is but the last adopted\nmetaphysical theory of science.\n\nWe also notice that it is very difficult, if not impossible, for the\ninquisitive scientist to limit himself strictly to the object-matter of\nhis own chosen field, and not to enquire more or less earnestly\u2014not\ninfrequently to dogmatize more or less positively\u2014respecting the results\nof other sciences and even respecting the foundations and processes of\nscientific inquiry itself. Thus Mr. Huxley in the first Essay of this\nSeries on _The Physical Basis of Life_, leaves the discussion of his\nappropriate theme in order to deliver sundry very positive and\npronounced assertions respecting the \u201climits of philosophical inquiry,\u201d\nand quotes with manifest satisfaction a dictum of David Hume that is\nsufficiently dogmatic and positive, as to what these limits are. In more\nthan one of his Lay sermons, he rushes headlong into the most pronounced\nassertions in respect to the nature of matter and of spirit. The\neloquent Tyndall, in No. 5, expounds at length _The Methods and\nTendencies of Physical Investigation_ and discourses eloquently, if\noccasionally somewhat poetically, of _The Scientific use of the\nImagination_. But Messrs. Huxley and Tyndall are eminent examples of\nscientists who are severely and successfully devoted respectively to\nphysiology and the higher physics. No one will contend that they have\nnot faithfully cultivated their appropriate fields of inquiry. The fact\nthat neither can be content to confine himself within his special field,\nforcibly illustrates the tendency of every modern science to concern\nitself with its relations to its neighbors, and the unresistible\nnecessity which forces the most rigid physicist to become a\nmetaphysician in spite of himself. So much for the appellation\n\u201c_Scientists_.\u201d\n\n\u201c_Half Hours_\u201d suggests the very natural inquiry\u2014What can a scientist\ncommunicate in half an hour, especially to a reader who may be ignorant\nof the elements of the science which he would expound? Does not the\nphrase _Half Hours with Modern Scientists_ stultify itself and suggest\nthe folly of any attempt to treat of science with effect in a series of\nessays? In reply we would ask the attention of the reader to the\nfollowing considerations.\n\nThe tendency is universal among the scientific men of all nations, to\npresent the principles of science in such brief summaries or statements\nas may bring them within the reach of common readers. The tendency\nindicates that there is a large body of readers who are so far\ninstructed in the elements of science as to be able to understand these\nsummaries. In England, Germany, France and this country such brief\nessays are abundant, either in the form of contributions to popular and\nscientific journals, or in that of popular lectures, or in that of brief\nmanuals, or of monographs on separate topics; especially such topics as\nare novel, or are interesting to the public for their theoretic\nbrilliancy, or their applications to industry and art.\n\nThese essays need not be and they are not always superficial, because\nthey are brief. They often are the more profound on account of their\nconciseness, as when they contain a condensed summary of the main\nprinciples of the art or science in question, or a brief history of the\nsuccessive experiments which have issued in some brilliant discovery.\nThese essays are very generally read, even though they are both concise\nand profound. But they could not be read even though they were less\nprofound than they are, were there not provided a numerous company of\nreaders who are sufficiently instructed in science to appreciate them.\nThat such a body of readers exists in the countries referred to, is\neasily explained by the existence of public schools and schools of\nscience and technology, by the enormous extension of the knowledge of\nmachinery, engineering, mining, dyeing, etc., etc., all of which imply a\nmore or less distinct recognition of scientific principles and stimulate\nthe curiosity in regard to scientific truth. Popular lectures also,\nillustrated by experiments, have been repeated before thousands of\nexcited listeners, and the eager and inventive minds of multitudes of\ningenious youths have been trained by this distribution of science, to\nthe capacity to comprehend the compact and pointed scientific essay,\neven though it taxes the attention and suspends the breath for a\nhalf-hour by its closeness and severity.\n\nThe fact is also worthy of notice, that many of the ablest scientists of\nour times have made a special study of the art of expounding and\npresenting scientific truth. Some of them have schooled themselves to\nthat lucid and orderly method by which a science seems to spring into\nbeing a second time, under the creative hand of its skilful expositor.\nOthers have made a special study of philosophic diction. Others have\nlearned how to adorn scientific truth with the embellishments of an\naffluent imagination. Some of the ablest writers of our time are found\namong the devotees of physical science. That a few scientific writers\nand lecturers may have exemplified some of the most offensive features\nof the demagogue and the sophist cannot be denied, but we may not forget\nthat many have attained to the consummate skill of the accomplished\nessayist and impressive and eloquent orator.\n\nOne advantage cannot be denied of this now popular and established\nmethod of setting forth scientific truth, viz., that it prescribes a\nconvenient method of bringing into contrast the arguments _for_ and\n_against_ any disputed position in science. If materialism can furnish\nits ready advocate with a convenient vehicle for its ready diffusion,\nthe antagonist theory can avail itself of a similar vehicle for the\ncommunication of the decisive and pungent reply. The one is certain to\ncall forth the other, and if the two are present side by side in the\nsame series, so much the better is it for the truth and so much the\nworse for the error. The teacher before his class, the lecturer in the\npresence of his audience, has the argument usually to himself; he allows\nfew questionings and admits no reply. An erroneous theory may entrench\nitself within a folio against arguments which would annihilate its\npositions if these were condensed in a tract.\n\nThis consideration should dispel all the alarm that is felt by the\ndefenders of religion in view of the general diffusion of popular\nscientific treatises. The brief statement of a false or groundless\nscientific theory, even by its defender, is often its most effectual\nrefutation. A magnificently imposing argument often shrinks into\ninsignificance when its advocate is forced to state its substance in a\ncompact and close-jointed outline. The articulations are seen to be\ndefective, the joints do not fit one another, the coherence is\nconspicuously wanting. Let then error do its utmost in the field of\nscience. Its deficient data and its illogical processes are certain to\nbe exposed, sometimes even by its own advocates. If this does not happen\nthe defender of that scientific truth which seems to be essential to the\nteachings and faiths of religion, must scrutinize its reasonings by the\nrules and methods of scientific inquiry. If science seems to be hostile\nto religion, this very seeming should arouse the defender of Theism and\nChristianity to examine into the grounds both by the light and methods\nwhich are appropriate to science itself. The more brief and compact and\npopular is the argument which he is to refute, the more feasible is the\ntask of exposure and reply. Only let this be a cardinal maxim with the\ndefender of the truth, that whatever is scientifically defended and\nmaintained must be scientifically refuted and overthrown. The great\nMaster of our faith never uttered a more comprehensive or a grander\nmaxim than the memorable words, \u201c_To this end was I born and for this\ncause came I into the world, that I should bear witness unto the truth.\nEveryone that is of the truth heareth my voice._\u201d It would be easy to\nshow that the belief in moral and religious truth and the freedom in\nsearching for and defending it which was inspired by these words have\nbeen most efficient in training the human mind to that faith in the\nresults of scientific investigation which characterize the modern\nscientist. That Christian believer must either have a very imperfect\nview of the spirit of his own faith, or a very narrow conception of the\nevidences and the effect of its teachings, who imagines that the freest\nspirit of scientific inquiry, or the most penetrating insight into the\nsecrets of matter or of spirit can have any other consequence than to\nstrengthen and brighten the evidence for Christian truth.\n\n                                                                   N. P.\n\n    YALE COLLEGE, _May_, 1872.\n\n\n------------------------------------------------------------------------\n\n\n\n\n                  PUBLISHERS\u2019 NOTE TO SECOND EDITION.\n\n\nThe five lectures embodied in this First Series of Half Hours with\nModern Scientists were first published as Nos. I.\u2014V. of the University\nScientific Series. In this series the publishers have aimed to give to\nthe public in a cheap pamphlet form, the advance thought in the\nScientific world. The intrinsic value of these lectures has created a\nvery general desire to have them put in a permanent form. They therefore\nhave brought them out in this style. Each five succeeding numbers of\nthis celebrated series will be printed and bound in uniform style with\nthis volume, and be designated as second series, third series, and so\non. Henceforth it will be the design of the publishers to give\npreference to those lectures and essays of American scientists which\ncontain original research and discovery, rather than to reprinting from\nEuropean sources. The lectures in the second series will be (1) On\nNatural Selection as Applied to Man, by Alfred Russel Wallace; (2) three\nprofoundly interesting lectures on Spectrum Analysis, by Profs. Roscoe,\nHuggins, and Lockyer; (3) the Sun and its Different Atmospheres, a\nlecture by Prof. C. A. Young, Ph.D., of Dartmouth College; (4) the Earth\na great Magnet, by Prof. A. M. Mayer, Ph.D., of Stevens Institute; and\n(5) the Mysteries of the Voice and Ear, by Prof. Ogden N. Rood, of\nColumbia College. The last three lectures contain many original\ndiscoveries and brilliant experiments, and are finely illustrated.\n\n\n------------------------------------------------------------------------\n\n\n\n\n                             \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n                    _ON THE PHYSICAL BASIS OF LIFE._\n                             \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n\n\n\n\n------------------------------------------------------------------------\n\n\n\n\n                             INTRODUCTION.\n\n\nThe following remarkable discourse was originally delivered in\nEdinburgh, November 18th, 1868, as the first of a series of Sunday\nevening addresses, upon non-religious topics, instituted by the Rev. J.\nCranbrook. It was subsequently published in London as the leading\narticle in the _Fortnightly Review_, for February, 1869, and attracted\nso much attention that five editions of that number of the magazine have\nalready been issued. It is now re-printed in this country, in permanent\nform, for the first time, and will doubtless prove of great interest to\nAmerican readers. The author is Thomas Henry Huxley, of London,\nProfessor of Natural History in the Royal School of Mines, and of\nComparative Anatomy and Physiology in the Royal College of Surgeons. He\nis also President of the Geological Society of London. Although\ncomparatively a young man, his numerous and valuable contributions to\nNatural Science entitle him to be considered one of the first of living\nNaturalists, especially in the departments of Zo\u00f6logy and Paleontology,\nto which he has mainly devoted himself. He is undoubtedly the ablest\nEnglish advocate of Darwin\u2019s theory of the Origin of Species,\nparticularly with reference to its application to the human race, which\nhe believes to be nearly related to the higher apes. It is, indeed,\nthrough his discussion of this question that he is, perhaps, best known\nto the general public, as his late work entitled \u201cMan\u2019s Place in\nNature,\u201d and other writings on similar topics, have been very widely\nread in this country and in Europe. In the present lecture Professor\nHuxley discusses a kindred subject of no less interest and importance,\nand should have an equally candid hearing.\n\nYALE COLLEGE, _March_ 30_th_, 1869.\n\n\n------------------------------------------------------------------------\n\n\n\n\n                     On the Physical Basis of Life.\n\n\nIn order to make the title of this discourse generally intelligible, I\nhave translated the term \u201cProtoplasm,\u201d which is the scientific name of\nthe substance of which I am about to speak, by the words \u201cthe physical\nbasis of life.\u201d I suppose that, to many, the idea that there is such a\nthing as a physical basis, or matter, of life may be novel\u2014so widely\nspread is the conception of life as a something which works through\nmatter, but is independent of it; and even those who are aware that\nmatter and life are inseparably connected, may not be prepared for the\nconclusion plainly suggested by the phrase \u201cthe physical basis or matter\nof life,\u201d that there is some one kind of matter which is common to all\nliving beings, and that their endless diversities are bound together by\na physical, as well as an ideal, unity. In fact, when first apprehended,\nsuch a doctrine as this appears almost shocking to common sense. What,\ntruly, can seem to be more obviously different from one another in\nfaculty, in form, and in substance, than the various kinds of living\nbeings? What community of faculty can there be between the\nbrightly-colored lichen, which so nearly resembles a mere mineral\nincrustation of the bare rock on which it grows, and the painter, to\nwhom it is instinct with beauty, or the botanist, whom it feeds with\nknowledge?\n\nAgain, think of the microscopic fungus\u2014a mere infinitesimal ovoid\nparticle, which finds space and duration enough to multiply into\ncountless millions in the body of a living fly; and then of the wealth\nof foliage, the luxuriance of flower and fruit, which lies between this\nbald sketch of a plant and the giant pine of California, towering to the\ndimensions of a cathedral spire, or the Indian fig, which covers acres\nwith its profound shadow, and endures while nations and empires come and\ngo around its vast circumference! Or, turning to the other half of the\nworld of life, picture to yourselves the great finner whale, hugest of\nbeasts that live, or have lived, disporting his eighty or ninety feet of\nbone, muscle and blubber, with easy roll, among waves in which the\nstoutest ship that ever left dockyard would founder hopelessly; and\ncontrast him with the invisible animalcules\u2014mere gelatinous specks,\nmultitudes of which could, in fact, dance upon the point of a needle\nwith the same ease as the angels of the schoolmen could, in imagination.\nWith these images before your minds, you may well ask what community of\nform, or structure, is there between the animalcule and the whale, or\nbetween the fungus and fig-tree? And, _a fortiori_, between all four?\n\nFinally, if we regard substance, or material composition, what hidden\nbond can connect the flower which a girl wears in her hair and the blood\nwhich courses through her youthful veins; or, what is there in common\nbetween the dense and resisting mass of the oak, or the strong fabric of\nthe tortoise, and those broad disks of glassy jelly which may be seen\npulsating through the waters of a calm sea, but which drain away to mere\nfilms in the hand which raises them out of their element? Such\nobjections as these must, I think, arise in the mind of every one who\nponders, for the first time, upon the conception of a single physical\nbasis of life underlying all the diversities of vital existence; but I\npropose to demonstrate to you that, notwithstanding these apparent\ndifficulties, a threefold unity\u2014namely, a unity of power or faculty, a\nunity of form, and a unity of substantial composition\u2014does pervade the\nwhole living world. No very abstruse argumentation is needed, in the\nfirst place, to prove that the powers, or faculties, of all kinds of\nliving matter, diverse as they may be in degree, are substantially\nsimilar in kind. Goethe has condensed a survey of all the powers of\nmankind into the well-known epigram:\n\n    \u201cWarum treibt sich das Volk so und schreit? Es will sich\n    ern\u00e4hren Kinder zeugen, und sie n\u00e4hren so gut es vermag.\n\n                  *       *       *       *       *\n\n    Weiter bringt es kein Mensch, stell\u2019 er sich, wie er auch will.\u201d\n\nIn physiological language this means, that all the multifarious and\ncomplicated activities of man are comprehensible under three categories.\nEither they are immediately directed towards the maintenance and\ndevelopment of the body, or they effect transitory changes in the\nrelative positions of parts of the body, or they tend towards the\ncontinuance of the species. Even those manifestations of intellect, of\nfeeling, and of will, which we rightly name the higher faculties, are\nnot excluded from this classification, inasmuch as to every one but the\nsubject of them, they are known only as transitory changes in the\nrelative positions of parts of the body. Speech, gesture, and every\nother form of human action are, in the long run, resolvable into\nmuscular contraction, and muscular contraction is but a transitory\nchange in the relative positions of the parts of a muscle. But the\nscheme, which is large enough to embrace the activities of the highest\nform of life, covers all those of the lower creatures. The lowest plant,\nor animalcule, feeds, grows and reproduces its kind. In addition, all\nanimals manifest those transitory changes of form which we class under\nirritability and contractility; and it is more than probable, that when\nthe vegetable world is thoroughly explored, we shall find all plants in\npossession of the same powers, at one time or other of their existence.\nI am not now alluding to such phenomena, at once rare and conspicuous,\nas those exhibited by the leaflets of the sensitive plant, or the\nstamens of the barberry, but to much more widely-spread, and, at the\nsame time, more subtle and hidden, manifestations of vegetable\ncontractility. You are doubtless aware that the common nettle owes its\nstinging property to the innumerable stiff and needle-like, though\nexquisitely delicate, hairs which cover its surface. Each\nstinging-needle tapers from a broad base to a slender summit, which,\nthough rounded at the end, is of such microscopic fineness that it\nreadily penetrates, and breaks off in, the skin. The whole hair consists\nof a very delicate outer case of wood, closely applied to the inner\nsurface of which is a layer of semi-fluid matter, full of innumerable\ngranules of extreme minuteness. This semi-fluid lining is protoplasm,\nwhich thus constitutes a kind of bag, full of a limpid liquid, and\nroughly corresponding in form with the interior of the hair which it\nfills. When viewed with a sufficiently high magnifying power, the\nprotoplasmic layer of the nettle hair is seen to be in a condition of\nunceasing activity. Local contractions of the whole thickness of its\nsubstance pass slowly and gradually from point to point, and give rise\nto the appearance of progressive waves, just as the bending of\nsuccessive stalks of corn by a breeze produces the apparent billows of a\ncorn-field. But, in addition to these movements, and independently of\nthem, the granules are driven, in relatively rapid streams, through\nchannels in the protoplasm which seem to have a considerable amount of\npersistence. Most commonly, the currents in adjacent parts of the\nprotoplasm take similar directions; and, thus, there is a general stream\nup one side of the hair and down the other. But this does not prevent\nthe existence of partial currents which take different routes; and,\nsometimes, trains of granules may be seen coursing swiftly in opposite\ndirections, within a twenty-thousandth of an inch of one another; while,\noccasionally, opposite streams come into direct collision, and, after a\nlonger or shorter struggle, one predominates. The cause of these\ncurrents seem to lie in contractions of the protoplasm which bounds the\nchannels in which they flow, but which are so minute that the best\nmicroscopes show only their effects, and not themselves.\n\nThe spectacle afforded by the wonderful energies prisoned within the\ncompass of the microscopic hair of a plant, which we commonly regard as\na merely passive organism, is not easily forgotten by one who has\nwatched its display continued hour after hour, without pause or sign of\nweakening. The possible complexity of many other organic forms,\nseemingly as simple as the protoplasm of the nettle, dawns upon one; and\nthe comparison of such a protoplasm to a body with an internal\ncirculation, which has been put forward by an eminent physiologist,\nloses much of its startling character. Currents similar to those of the\nhairs of the nettle have been observed in a great multitude of very\ndifferent plants, and weighty authorities have suggested that they\nprobably occur, in more or less perfection, in all young vegetable\ncells. If such be the case, the wonderful noonday silence of a tropical\nforest is, after all, due only to the dullness of our hearing; and could\nour ears catch the murmur of these tiny maelstroms, as they whirl in the\ninnumerable myriads of living cells which constitute each tree, we\nshould be stunned, as with the roar of a great city.\n\nAmong the lower plants, it is the rule rather than the exception, that\ncontractility should be still more openly manifested at some periods of\ntheir existence. The protoplasm of _Alg\u00e6_ and _Fungi_ becomes, under\nmany circumstances, partially, or completely, freed from its woody case,\nand exhibits movements of its whole mass, or is propelled by the\ncontractility of one or more hair-like prolongations of its body, which\nare called vibratile cilia. And, so far as the conditions of the\nmanifestation of the phenomena of contractility have yet been studied,\nthey are the same for the plant as for the animal. Heat and electric\nshocks influence both, and in the same way, though it may be in\ndifferent degrees. It is by no means my intention to suggest that there\nis no difference in faculty between the lowest plant and the highest, or\nbetween plants and animals. But the difference between the powers of the\nlowest plant, or animal, and those of the highest is one of degree, not\nof kind, and depends, as Milne-Edwards long ago so well pointed out,\nupon the extent to which the principle of the division of labor is\ncarried out in the living economy. In the lowest organism all parts are\ncompetent to perform all functions, and one and the same portion of\nprotoplasm may successively take on the function of feeding, moving, or\nreproducing apparatus. In the highest, on the contrary, a great number\nof parts combine to perform each function, each part doing its allotted\nshare of the work with great accuracy and efficiency, but being useless\nfor any other purpose. On the other hand, notwithstanding all the\nfundamental resemblances which exist between the powers of the\nprotoplasm in plants and in animals, they present a striking difference\n(to which I shall advert more at length presently,) in the fact that\nplants can manufacture fresh protoplasm out of mineral compounds,\nwhereas animals are obliged to procure it ready-made, and hence, in the\nlong run, depend upon plants. Upon what condition this difference in the\npowers of the two great divisions of the world of life depends, nothing\nis at present known.\n\nWith such qualification as arises out of the last-mentioned fact, it may\nbe truly said that the acts of all living things are fundamentally one.\nIs any such unity predicable of their forms? Let us seek in easily\nverified facts for a reply to this question. If a drop of blood be drawn\nby pricking one\u2019s finger, and viewed with proper precautions and under a\nsufficiently high microscopic power, there will be seen, among the\ninnumerable multitude of little, circular, discoidal bodies, or\ncorpuscles, which float in it and give it its color, a comparatively\nsmall number of colorless corpuscles, of somewhat larger size and very\nirregular shape. If the drop of blood be kept at the temperature of the\nbody, these colorless corpuscles will be seen to exhibit a marvelous\nactivity, changing their forms with great rapidity, drawing in and\nthrusting out prolongations of their substance, and creeping about as if\nthey were independent organisms. The substance which is thus active is a\nmass of protoplasm, and its activity differs in detail, rather than in\nprinciple, from that of the protoplasm of the nettle. Under sundry\ncircumstances the corpuscle dies and becomes distended into a round\nmass, in the midst of which is seen a smaller spherical body, which\nexisted, but was more or less hidden, in the living corpuscle, and is\ncalled its _nucleus_. Corpuscles of essentially similar structure are to\nbe found in the skin, in the lining of the mouth, and scattered through\nthe whole frame work of the body. Nay, more; in the earliest condition\nof the human organism, in that state in which it has just become\ndistinguishable from the egg in which it arises, it is nothing but an\naggregation of such corpuscles, and every organ of the body was, once,\nno more than such an aggregation. Thus a nucleated mass of protoplasm\nturns out to be what may be termed the structural unit of the human\nbody. As a matter of fact, the body, in its earliest state, is a mere\nmultiple of such units; and, in its perfect condition, it is a multiple\nof such units, variously modified. But does the formula which expresses\nthe essential structural character of the highest animal cover all the\nrest, as the statement of its powers and faculties covered that of all\nothers? Very nearly. Beast and fowl, reptile and fish, mollusk, worm,\nand polype, are all composed of structural units of the same character,\nnamely, masses of protoplasm with a nucleus. There are sundry very low\nanimals, each of which, structurally, is a mere colorless\nblood-corpuscle, leading an independent life. But, at the very bottom of\nthe animal scale, even this simplicity becomes simplified, and all the\nphenomena of life are manifested by a particle of protoplasm without a\nnucleus. Nor are such organisms insignificant by reason of their want of\ncomplexity. It is a fair question whether the protoplasm of those\nsimplest forms of life, which people an immense extent of the bottom of\nthe sea, would not outweigh that of all the higher living beings which\ninhabit the land, put together. And in ancient times, no less than at\nthe present day, such living beings as these have been the greatest of\nrock builders.\n\nWhat has been said of the animal world is no less true of plants.\nImbedded in the protoplasm at the broad, or attached, end of the nettle\nhair, there lies a spheroidal nucleus. Careful examination further\nproves that the whole substance of the nettle is made up of a repetition\nof such masses of nucleated protoplasm, each contained in a wooden case,\nwhich is modified in form, sometimes into a woody fibre, sometimes into\na duct or spiral vessel, sometimes into a pollen grain, or an ovule.\nTraced back to its earliest state, the nettle arises as the man does, in\na particle of nucleated protoplasm. And in the lowest plants, as in the\nlowest animals, a single mass of such protoplasm may constitute the\nwhole plant, or the protoplasm may exist without a nucleus. Under these\ncircumstances it may well be asked, how is one mass of non-nucleated\nprotoplasm to be distinguished from another? why call one \u201cplant\u201d and\nthe other \u201canimal?\u201d The only reply is that, so far as form is concerned,\nplants and animals are not separable, and that, in many cases, it is a\nmere matter of convention whether we call a given organism an animal or\na plant.\n\nThere is a living body called _\u00c6thalium septicum_, which appears upon\ndecaying vegetable substances, and in one of its forms, is common upon\nthe surface of tan pits. In this condition it is, to all intents and\npurposes, a fungus, and formerly was always regarded as such; but the\nremarkable investigations of De Bary have shown that, in another\ncondition, the _\u00c6thalium_ is an actively locomotive creature, and takes\nin solid matters, upon which, apparently, it feeds, thus exhibiting the\nmost characteristic feature of animality. Is this a plant, or is it an\nanimal? Is it both, or is it neither? Some decide in favor of the last\nsupposition, and establish an intermediate kingdom, a sort of biological\nNo Man\u2019s Land for all these questionable forms. But, as it is admittedly\nimpossible to draw any distinct boundary line between this no man\u2019s land\nand the vegetable world on the one hand, or the animal, on the other, it\nappears to me that this proceeding merely doubles the difficulty which,\nbefore, was single. Protoplasm, simple or nucleated, is the formal basis\nof all life. It is the clay of the potter; which, bake it and paint it\nas he will, remains clay, separated by artifice, and not by nature, from\nthe commonest brick or sun-dried clod. Thus it becomes clear that all\nliving powers are cognate, and that all living forms are fundamentally\nof one character.\n\nThe researches of the chemist have revealed a no less striking\nuniformity of material composition in living matter. In perfect\nstrictness, it is true that chemical investigation can tell us little or\nnothing, directly, of the composition of living matter, inasmuch as such\nmatter must needs die in the act of analysis, and upon this very obvious\nground, objections, which I confess seem to me to be somewhat frivolous,\nhave been raised to the drawing of any conclusions whatever respecting\nthe composition of actually living matter from that of the dead matter\nof life, which alone is accessible to us. But objectors of this class do\nnot seem to reflect that it is also, in strictness, true that we know\nnothing about the composition of any body whatever, as it is. The\nstatement that a crystal of calc-spar consists of carbonate of lime, is\nquite true, if we only mean that, by appropriate processes, it may be\nresolved into carbonic acid and quicklime. If you pass the same carbonic\nacid over the very quicklime thus obtained, you will obtain carbonate of\nlime again; but it will not be calc-spar, nor anything like it. Can it,\ntherefore, be said that chemical analysis teaches nothing about the\nchemical composition of calc-spar? Such a statement would be absurd; but\nit is hardly more so than the talk one occasionally hears about the\nuselessness of applying the results of chemical analysis to the living\nbodies which have yielded them. One fact, at any rate, is out of reach\nof such refinements, and this is, that all the forms of protoplasm which\nhave yet been examined contain the four elements, carbon, hydrogen,\noxygen, and nitrogen, in very complex union, and that they behave\nsimilarly towards several reagents. To this complex combination, the\nnature of which has never been determined with exactness, the name of\nProtein has been applied. And if we use this term with such caution as\nmay properly arise out of our comparative ignorance of the things for\nwhich it stands, it may be truly said, that all protoplasm is\nproteinaceous; or, as the white, or albumen, of an egg is one of the\ncommonest examples of a nearly pure protein matter, we may say that all\nliving matter is more or less albuminoid. Perhaps it would not yet be\nsafe to say that all forms of protoplasm are affected by the direct\naction of electric shocks; and yet the number of cases in which the\ncontraction of protoplasm is shown to be affected by this agency\nincreases, every day. Nor can it be affirmed with perfect confidence\nthat all forms of protoplasm are liable to undergo that peculiar\ncoagulation at the temperature of 40 degrees\u201450 degrees centigrade,\nwhich has been called \u201cheat-stiffening,\u201d though K\u00fchne\u2019s beautiful\nresearches have proved this occurrence to take place in so many and such\ndiverse living beings, that it is hardly rash to expect that the law\nholds good for all. Enough has, perhaps, been said to prove the\nexistence of a general uniformity in the character of the protoplasm, or\nphysical basis of life, in whatever group of living beings it may be\nstudied. But it will be understood that this general uniformity by no\nmeans excludes any amount of special modifications of the fundamental\nsubstance. The mineral, carbonate of lime, assumes an immense diversity\nof characters, though no one doubts that under all these Protean changes\nit is one and the same thing.\n\nAnd now, what is the ultimate fate, and what the origin of the matter of\nlife? Is it, as some of the older naturalists supposed, diffused\nthroughout the universe in molecules, which are indestructible and\nunchangeable in themselves; but, in endless transmigration, unite in\ninnumerable permutations, into the diversified forms of life we know?\nOr, is the matter of life composed of ordinary matter, differing from it\nonly in the manner in which its atoms are aggregated? Is it built up of\nordinary matter, and again resolved into ordinary matter when its work\nis done? Modern science does not hesitate a moment between these\nalternatives. Physiology writes over the portals of life,\n\n                     \u201cDebemur morti nos nostraque,\u201d\n\nwith a profounder meaning than the Roman poet attached to that\nmelancholy line. Under whatever disguise it takes refuge, whether fungus\nor oak, worm or man, the living protoplasm not only ultimately dies and\nis resolved into its mineral and lifeless constituents, but is always\ndying, and, strange as the paradox may sound, could not live unless it\ndied. In the wonderful story of the \u201cPeau de Chagrin,\u201d the hero becomes\npossessed of a magical wild ass\u2019s skin, which yields him the means of\ngratifying all his wishes. But its surface represents the duration of\nthe proprietor\u2019s life; and for every satisfied desire the skin shrinks\nin proportion to the intensity of fruition, until at length life and the\nlast handbreadth of the \u201cPeau de Chagrin,\u201d disappear with the\ngratification of a last wish. Balzac\u2019s studies had led him over a wide\nrange of thought and speculation, and his shadowing forth of\nphysiological truth in this strange story may have been intentional. At\nany rate, the matter of life is a veritable \u201cPeau de Chagrin,\u201d and for\nevery vital act it is somewhat the smaller. All work implies waste, and\nthe work of life results, directly or indirectly, in the waste of\nprotoplasm. Every word uttered by a speaker costs him some physical\nloss; and, in the strictest sense, he burns that others may have\nlight\u2014so much eloquence, so much of his body resolved into carbonic\nacid, water and urea. It is clear that this process of expenditure\ncannot go on forever. But, happily, the protoplasmic _peau de chagrin_\ndiffers from Balzac\u2019s in its capacity of being repaired, and brought\nback to its full size, after every exertion. For example, this present\nlecture, whatever its intellectual worth to you, has a certain physical\nvalue to me, which is, conceivably, expressible by the number of grains\nof protoplasm and other bodily substance wasted in maintaining my vital\nprocesses during its delivery. My _peau de chagrin_ will be distinctly\nsmaller at the end of the discourse than it was at the beginning.\nBy-and-by, I shall probably have recourse to the substance commonly\ncalled mutton, for the purpose of stretching it back to its original\nsize. Now this mutton was once the living protoplasm, more or less\nmodified, of another animal\u2014a sheep. As I shall eat it, it is the same\nmatter altered, not only by death, but by exposure to sundry artificial\noperations in the process of cooking. But these changes, whatever be\ntheir extent, have not rendered it incompetent to resume its old\nfunctions as matter of life. A singular inward laboratory, which I\npossess, will dissolve a certain portion of the modified protoplasm, the\nsolution so formed will pass into my veins; and the subtle influences to\nwhich it will then be subjected will convert the dead protoplasm into\nliving protoplasm, and transubstantiate sheep into man. Nor is this all.\nIf digestion were a thing to be trifled with, I might sup upon lobster,\nand the matter of life of the crustacean would undergo the same\nwonderful metamorphosis into humanity. And were I to return to my own\nplace by sea, and undergo shipwreck, the crustacea might, and probably\nwould, return the compliment, and demonstrate our common nature by\nturning my protoplasm into living lobster. Or, if nothing better were to\nbe had, I might supply my wants with mere bread, and I should find the\nprotoplasm of the wheat-plant to be convertible into man, with no more\ntrouble than that of the sheep, and with far less, I fancy, than that of\nthe lobster. Hence it appears to be a matter of no great moment what\nanimal, or what plant, I lay under contribution for protoplasm, and the\nfact speaks volumes for the general identity of that substance in all\nliving beings. I share this catholicity of assimilation with other\nanimals, all of which, so far as we know, could thrive equally well on\nthe protoplasm of any of their fellows, or of any plant; but here the\nassimilative powers of the animal world cease.\n\nA solution of smelling-salts in water with an infinitesimal proportion\nof some other saline matters, contains all the elementary bodies which\nenter into the composition of protoplasm; but, as I need hardly say, a\nhogshead of that fluid would not keep a hungry man from starving, nor\nwould it save any animal whatever from a like fate. An animal cannot\nmake protoplasm, but must take it ready-made from some other animal, or\nsome plant\u2014the animal\u2019s highest feat of constructive chemistry being to\nconvert dead protoplasm into that living matter of life which is\nappropriate to itself. Therefore, in seeking for the origin of\nprotoplasm, we must eventually turn to the vegetable world. The fluid\ncontaining carbonic acid, water, and ammonia, which offers such a\nbarmecide feast to the animal, is a table richly spread to multitudes of\nplants; and with a due supply of only such materials, many a plant will\nnot only maintain itself in vigor, but grow and multiply until it has\nincreased a million-fold, or a million million-fold, the quantity of\nprotoplasm which it originally possessed; in this way building up the\nmatter of life, to an indefinite extent, from the common matter of the\nuniverse. Thus the animal can only raise the complex substance of dead\nprotoplasm to the higher power, as one may say, of living protoplasm;\nwhile the plant can raise the less complex substances\u2014carbonic acid,\nwater, and ammonia\u2014to the same stage of living protoplasm, if not to the\nsame level. But the plant also has its limitations. Some of the fungi,\nfor example, appear to need higher compounds to start with, and no known\nplant can live upon the uncompounded elements of protoplasm. A plant\nsupplied with pure carbon, hydrogen, oxygen, and nitrogen, phosphorus,\nsulphur, and the like, would as infallibly die as the animal in his bath\nof smelling-salts, though it would be surrounded by all the constituents\nof protoplasm. Nor, indeed, need the process of simplification of\nvegetable food be carried so far as this, in order to arrive at the\nlimit of the plant\u2019s thaumaturgy.\n\nLet water, carbonic acid, and all the other needful constituents, be\nsupplied without ammonia, and an ordinary plant will still be unable to\nmanufacture protoplasm. Thus the matter of life, so far as we know it\n(and we have no right to speculate on any other) breaks up in\nconsequence of that continual death which is the condition of its\nmanifesting vitality, into carbonic acid, water, and ammonia, which\ncertainly possess no properties but those of ordinary matter; and out of\nthese same forms of ordinary matter and from none which are simpler, the\nvegetable world builds up all the protoplasm which keeps the animal\nworld agoing. Plants are the accumulators of the power which animals\ndistribute and disperse.\n\nBut it will be observed, that the existence of the matter of life\ndepends on the pre\u00ebxistence of certain compounds, namely, carbonic acid,\nwater, and ammonia. Withdraw any one of these three from the world and\nall vital phenomena come to an end. They are related to the protoplasm\nof the plant, as the protoplasm of the plant is to that of the animal.\nCarbon, hydrogen, oxygen, and nitrogen are all lifeless bodies. Of\nthese, carbon and oxygen unite in certain proportion and under certain\nconditions, to give rise to carbonic acid; hydrogen and oxygen produce\nwater; nitrogen and hydrogen give rise to ammonia. These new compounds,\nlike the elementary bodies of which they are composed, are lifeless. But\nwhen they are brought together, under certain conditions they give rise\nto the still more complex body, protoplasm, and this protoplasm exhibits\nthe phenomena of life. I see no break in this series of steps in\nmolecular complication, and I am unable to understand why the language\nwhich is applicable to any one term of the series may not be used to any\nof the others. We think fit to call different kinds of matter carbon,\noxygen, hydrogen, and nitrogen, and to speak of the various powers and\nactivities of these substances as the properties of the matter of which\nthey are composed. When hydrogen and oxygen are mixed in a certain\nproportion, and the electric spark is passed through them, they\ndisappear and a quantity of water, equal in weight to the sum of their\nweights, appears in their place. There is not the slightest parity\nbetween the passive and active powers of the water and those of the\noxygen and hydrogen which have given rise to it. At 32 degrees\nFahrenheit, and far below that temperature, oxygen and hydrogen are\nelastic gaseous bodies, whose particles tend to rush away from one\nanother with great force. Water, at the same temperature, is a strong\nthough brittle solid, whose particles tend to cohere into definite\ngeometrical shapes, and sometimes build up frosty imitations of the most\ncomplex forms of vegetable foliage. Nevertheless we call these, and many\nother strange phenomena, the properties of the water, and we do not\nhesitate to believe that, in some way or another, they result from the\nproperties of the component elements of the water. We do not assume that\na something called \u201caquosity\u201d entered into and took possession of the\noxide of hydrogen as soon as it was formed, and then guided the aqueous\nparticles to their places in the facets of the crystal, or amongst the\nleaflets of the hoar-frost. On the contrary, we live in the hope and in\nthe faith that, by the advance of molecular physics, we shall by-and-by\nbe able to see our way as clearly from the constituents of water to the\nproperties of water, as we are now able to deduce the operations of a\nwatch from the form of its parts and the manner in which they are put\ntogether. Is the case in any way changed when carbonic acid, water and\nammonia disappear, and in their place, under the influence of\npre\u00ebxisting living protoplasm, an equivalent weight of the matter of\nlife makes its appearance? It is true that there is no sort of parity\nbetween the properties of the components and the properties of the\nresultant, but neither was there in the case of the water. It is also\ntrue that what I have spoken of as the influence of pre\u00ebxisting living\nmatter is something quite unintelligible; but does any body quite\ncomprehend the _modus operandi_ of an electric spark, which traverses a\nmixture of oxygen and hydrogen? What justification is there, then, for\nthe assumption of the existence in the living matter of a something\nwhich has no representative or correlative in the not living matter\nwhich gave rise to it? What better philosophical status has \u201cvitality\u201d\nthan \u201caquosity?\u201d And why should \u201cvitality\u201d hope for a better fate than\nthe other \u201citys\u201d which have disappeared since Martinus Scriblerus\naccounted for the operation of the meat-jack by its inherent \u201cmeat\nroasting quality,\u201d and scorned the \u201cmaterialism\u201d of those who explained\nthe turning of the spit by a certain mechanism worked by the draught of\nthe chimney? If scientific language is to possess a definite and\nconstant signification whenever it is employed, it seems to me that we\nare logically bound to apply to the protoplasm, or physical basis of\nlife, the same conceptions as those which are held to be legitimate\nelsewhere. If the phenomena exhibited by water are its properties, so\nare those presented by protoplasm, living or dead, its properties. If\nthe properties of water may be properly said to result from the nature\nand disposition of its component molecules, I can find no intelligible\nground for refusing to say that the properties of protoplasm result from\nthe nature and disposition of its molecules. But I bid you beware that,\nin accepting these conclusions, you are placing your feet on the first\nrung of a ladder which, in most people\u2019s estimation, is the reverse of\nJacob\u2019s, and leads to the antipodes of heaven. It may seem a small thing\nto admit that the dull vital actions of a fungus, or a foraminifer, are\nthe properties of their protoplasm, and are the direct results of the\nnature of the matter of which they are composed.\n\nBut if, as I have endeavored to prove to you, their protoplasm is\nessentially identical with, and most readily converted into, that of any\nanimal, I can discover no logical halting place between the admission\nthat such is the case, and the further concession that all vital action\nmay, with equal propriety, be said to be the result of the molecular\nforces of the protoplasm which displays it. And if so, it must be true,\nin the same sense and to the same extent, that the thoughts to which I\nam now giving utterance, and your thoughts regarding them, are the\nexpression of molecular changes in that matter of life which is the\nsource of our other vital phenomena. Past experience leads me to be\ntolerably certain that, when the propositions I have just placed before\nyou are accessible to public comment and criticism, they will be\ncondemned by many zealous persons, and perhaps by some few of the wise\nand thoughtful. I should not wonder if \u201cgross and brutal materialism\u201d\nwere the mildest phrase applied to them in certain quarters. And most\nundoubtedly the terms of the propositions are distinctly materialistic.\nNevertheless, two things are certain: the one, that I hold the\nstatements to be substantially true; the other, that I, individually, am\nno materialist, but, on the contrary, believe materialism to involve\ngrave philosophical error.\n\nThis union of materialistic terminology with the repudiation of\nmaterialistic philosophy I share with some of the most thoughtful men\nwith whom I am acquainted. And, when I first undertook to deliver the\npresent discourse, it appeared to me to be a fitting opportunity to\nexplain how such an union is not only consistent with, but necessitated\nby sound logic. I purposed to lead you through the territory of vital\nphenomena to the materialistic slough in which you find yourselves now\nplunged, and then to point out to you the sole path by which, in my\njudgment, extrication is possible. An occurrence, of which I was unaware\nuntil my arrival here last night, renders this line of argument\nsingularly opportune. I found in your papers the eloquent address \u201cOn\nthe Limits of Philosophical Inquiry,\u201d which a distinguished prelate of\nthe English Church delivered before the members of the Philosophical\nInstitution on the previous day. My argument, also, turns upon this very\npoint of limits of philosophical inquiry; and I cannot bring out my own\nviews better than by contrasting them with those so plainly, and, in the\nmain, fairly stated by the Archbishop of York. But I may be permitted to\nmake a preliminary comment upon an occurrence that greatly astonished\nme. Applying the name of \u201cthe New Philosophy\u201d to that estimate of the\nlimits of philosophical inquiry which I, in common with many other men\nof science, hold to be just, the Archbishop opens his address by\nidentifying this \u201cnew philosophy\u201d with the positive philosophy of M.\nComte (of whom he speaks as its \u201cfounder\u201d); and then proceeds to attack\nthat philosopher and his doctrine vigorously. Now, so far as I am\nconcerned, the most Reverend prelate might dialectically hew M. Comte in\npieces, as a modern Agag, and I should not attempt to stay his hand. In\nso far as my study of what specially characterizes the Positive\nPhilosophy has led me, I find therein little or nothing of any\nscientific value, and a great deal which is as thoroughly antagonistic\nto the very essence of science as anything in ultramontane Catholicism.\nIn fact, M. Comte\u2019s philosophy in practice might be compendiously\ndescribed as Catholicism _minus_ Christianity. But what has Comptism to\ndo with the \u201cNew Philosophy,\u201d as the Archbishop defines it in the\nfollowing passage?\n\n\u201cLet me briefly remind you of the leading principles of this new\nphilosophy.\n\n\u201cAll knowledge is experience of facts acquired by the senses. The\ntraditions of older philosophies have obscured our experience by mixing\nwith it much that the senses cannot observe, and until these additions\nare discarded our knowledge is impure. Thus, metaphysics tells us that\none fact which we observe is a cause, and another is the effect of that\ncause; but upon a rigid analysis we find that our senses observe nothing\nof cause or effect; they observe, first, that one fact succeeds another,\nand, after some opportunity, that this fact has never failed to\nfollow\u2014that for cause and effect we should substitute invariable\nsuccession. An older philosophy teaches us to define an object by\ndistinguishing its essential from its accidental qualities; but\nexperience knows nothing of essential and accidental; she sees only that\ncertain marks attach to an object, and, after many observations, that\nsome of them attach invariably, whilst others may at times be absent. *\n* * * * As all knowledge is relative, the notion of anything being\nnecessary must be banished with other traditions.\u201d\n\nThere is much here that expresses the spirit of the \u201cNew Philosophy,\u201d if\nby that term be meant the spirit of modern science; but I cannot but\nmarvel that the assembled wisdom and learning of Edinburgh should have\nuttered no sign of dissent, when Comte was declared to be the founder of\nthese doctrines. No one will accuse Scotchmen of habitually forgetting\ntheir great countrymen; but it was enough to make David Hume turn in his\ngrave, that here, almost within ear-shot of his house, an instructed\naudience should have listened, without a murmur, while his most\ncharacteristic doctrines were attributed to a French writer of fifty\nyears later date, in whose dreary and verbose pages we miss alike the\nvigor of thought and the exquisite clearness of the style of the man\nwhom I make bold to term the most acute thinker of the eighteenth\ncentury\u2014even though that century produced Kant. But I did not come to\nScotland to vindicate the honor of one of the greatest men she has ever\nproduced. My business is to point out to you that the only way of escape\nout of the crass materialism in which we just now landed is the adoption\nand strict working out of the very principles which the Archbishop holds\nup to reprobation.\n\nLet us suppose that knowledge is absolute, and not relative, and\ntherefore, that our conception of matter represents that which it really\nis. Let us suppose, further, that we do know more of cause and effect\nthan a certain definite order of succession among facts, and that we\nhave a knowledge of the necessity of that succession\u2014and hence, of\nnecessary laws\u2014and I, for my part, do not see what escape there is from\nutter materialism and necessitarianism. For it is obvious that our\nknowledge of what we call the material world is, to begin with, at least\nas certain and definite as that of the spiritual world, and that our\nacquaintance with the law is of as old a date as our knowledge of\nspontaneity.\n\nFurther, I take it to be demonstrable that it is utterly impossible to\nprove that anything whatever may not be the effect of a material and\nnecessary cause, and that human logic is equally incompetent to prove\nthat any act is really spontaneous. A really spontaneous act is one\nwhich, by the assumption, has no cause; and the attempt to prove such a\nnegative as this is, on the face of the matter, absurd. And while it is\nthus a philosophical impossibility to demonstrate that any given\nphenomenon is not the effect of a material cause, any one who is\nacquainted with the history of science will admit, that its progress\nhas, in all ages, meant, and now more than ever means, the extension of\nthe province of what we call matter and causation, and the concomitant\ngradual banishment from all regions of human thought of what we call\nspirit and spontaneity.\n\nI have endeavored, in the first part of this discourse, to give you a\nconception of the direction towards which modern physiology is tending;\nand I ask you, what is the difference between the conception of life as\nthe product of a certain disposition of material molecules, and the old\nnotion of an Arch\u00e6us governing and directing blind matter within each\nliving body, except this\u2014that here, as elsewhere, matter and law have\ndevoured spirit and spontaneity? And as surely as every future grows out\nof past and present, so will the physiology of the future gradually\nextend the realm of matter and law until it is co\u00ebxtensive with\nknowledge, with feeling, and with action. The consciousness of this\ngreat truth weighs like a nightmare, I believe, upon many of the best\nminds of these days. They watch what they conceive to be the progress of\nmaterialism, in such fear and powerless anger as a savage feels, when,\nduring an eclipse, the great shadow creeps over the face of the sun. The\nadvancing tide of matter threatens to drown their souls; the tightening\ngrasp of law impedes their freedom; they are alarmed lest man\u2019s moral\nnature be debased by the increase of his wisdom.\n\nIf the \u201cNew Philosophy\u201d be worthy of the reprobation with which it is\nvisited, I confess their fears seem to me to be well founded. While, on\nthe contrary, could David Hume be consulted, I think he would smile at\ntheir perplexities, and chide them for doing even as the heathen, and\nfalling down in terror before the hideous idols their own hands have\nraised. For, after all, what do we know of this terrible \u201cmatter,\u201d\nexcept as a name for the unknown and hypothetical cause of states of our\nown consciousness? And what do we know of that \u201cspirit\u201d over whose\nthreatened extinction by matter a great lamentation is arising, like\nthat which was heard at the death of Pan, except that it is also a name\nfor an unknown and hypothetical cause, or condition, of states of\nconsciousness? In other words, matter and spirit are but names for the\nimaginary substrata of groups of natural phenomena. And what is the dire\nnecessity and \u201ciron\u201d law under which men groan? Truly, most gratuitously\ninvented bugbears. I suppose if there be an \u201ciron\u201d law, it is that of\ngravitation; and if there be a physical necessity, it is that a stone,\nunsupported, must fall to the ground. But what is all we really know and\ncan know about the latter phenomenon? Simply, that, in all human\nexperience, stones have fallen to the ground under these conditions;\nthat we have not the smallest reason for believing that any stone so\ncircumstanced will not fall to the ground, and that we have, on the\ncontrary, every reason to believe that it will so fall. It is very\nconvenient to indicate that all the conditions of belief have been\nfulfilled in this case, by calling the statement that unsupported stones\nwill fall to the ground, \u201ca law of nature.\u201d But when, as commonly\nhappens, we change will into must, we introduce an idea of necessity\nwhich most assuredly does not lie in the observed facts, and has no\nwarranty that I can discover elsewhere. For my part, I utterly repudiate\nand anathematize the intruder. Fact, I know; and Law I know; but what is\nthis Necessity, save an empty shadow of my own mind\u2019s throwing? But, if\nit is certain that we can have no knowledge of the nature of either\nmatter or spirit, and that the notion of necessity is something\nillegitimately thrust into the perfectly legitimate conception of law,\nthe materialistic position that there is nothing in the world but\nmatter, force, and necessity, is as utterly devoid of justification as\nthe most baseless of theological dogmas.\n\nThe fundamental doctrines of materialism, like those of spiritualism,\nand most other \u201cisms,\u201d lie outside \u201cthe limits of philosophical\ninquiry,\u201d and David Hume\u2019s great service to humanity is his irrefragable\ndemonstration of what these limits are. Hume called himself a sceptic,\nand therefore others cannot be blamed if they apply the same title to\nhim; but that does not alter the fact that the name, with its existing\nimplications, does him gross injustice. If a man asks me what the\npolitics of the inhabitants of the moon are, and I reply that I do not\nknow; that neither I, nor any one else have any means of knowing; and\nthat, under these circumstances I decline to trouble myself about the\nsubject at all, I do not think he has any right to call me a sceptic. On\nthe contrary, in replying thus, I conceive that I am simply honest and\ntruthful, and show a proper regard for the economy of time. So Hume\u2019s\nstrong and subtle intellect takes up a great many problems about which\nwe are naturally curious, and shows us that they are essentially\nquestions of lunar politics, in their essence incapable of being\nanswered, and therefore not worth the attention of men who have work to\ndo in the world. And thus ends one of his essays:\n\n    \u201cIf we take in hand any volume of Divinity, or school\n    metaphysics, for instance, let us ask, _Does it contain any\n    abstract reasoning concerning quantity or number?_ No. _Does it\n    contain any experimental reasoning concerning matter of fact and\n    existence?_ No. Commit it then to the flames; for it can contain\n    nothing but sophistry and illusion.\u201d\n\nPermit me to enforce this most wise advice. Why trouble ourselves about\nmatters of which, however important they may be, we do know nothing, and\ncan know nothing? We live in a world which is full of misery and\nignorance, and the plain duty of each and all of us is to try to make\nthe little corner he can influence somewhat less miserable and somewhat\nless ignorant than it was before he entered it. To do this effectually\nit is necessary to be fully possessed of only two beliefs: the first,\nthat the order of nature is ascertainable by our faculties to an extent\nwhich is practically unlimited; the second, that our volition counts for\nsomething as a condition of the course of events. Each of these beliefs\ncan be verified experimentally, as often as we like to try. Each,\ntherefore, stands upon the strongest foundation upon which any belief\ncan rest; and forms one of our highest truths.\n\nIf we find that the ascertainment of the order of nature is facilitated\nby using one terminology, or one set of symbols, rather than another, it\nis our clear duty to use the former, and no harm can accrue so long as\nwe bear in mind that we are dealing merely with terms and symbols. In\nitself it is of little moment whether we express the phenomena of matter\nin terms of spirit, or the phenomena of spirit in terms of matter;\nmatter may be regarded as a form of thought, thought may be regarded as\na property of matter\u2014each statement has a certain relative truth. But\nwith a view to the progress of science, the materialistic terminology is\nin every way to be preferred. For it connects thought with the other\nphenomena of the universe, and suggests inquiry into the nature of those\nphysical conditions or concomitants of thought, which are more or less\naccessible to us, and a knowledge of which may, in future, help us to\nexercise the same kind of control over the world of thought as we\nalready possess in respect of the material world; whereas, the\nalternative, or spiritualistic, terminology is utterly barren, and leads\nto nothing but obscurity and confusion of ideas. Thus there can be\nlittle doubt that the further science advances, the more extensively and\nconsistently will all the phenomena of nature be represented by\nmaterialistic formul\u00e6 and symbols. But the man of science, who,\nforgetting the limits of philosophical inquiry, slides from these\nformul\u00e6 and symbols into what is commonly understood by materialism,\nseems to me to place himself on a level with the mathematician, who\nshould mistake the _x\u2019s_ and _y\u2019s_, with which he works his problems,\nfor real entities\u2014and with this further disadvantage as compared with\nthe mathematician, that the blunders of the latter are of no practical\nconsequence, while the errors of systematic materialism may paralyze the\nenergies and destroy the beauty of a life.\n\n\n------------------------------------------------------------------------\n\n\n\n\n            _THE CORRELATION OF VITAL AND PHYSICAL FORCES._\n\n\n\n\n------------------------------------------------------------------------\n\n\n\n\n                            THE CORRELATION\n\n                                   OF\n\n                       VITAL AND PHYSICAL FORCES.\n\n\nIn the Syracusan Poecile, says Alexander von Humboldt in his beautiful\nlittle allegory of the Rhodian Genius, hung a painting, which, for full\na century, had continued to attract the attention of every visitor. In\nthe foreground of this picture a numerous company of youths and maidens\nof earthly and sensuous appearance gazed fixedly upon a haloed Genius\nwho hovered in their midst. A butterfly rested upon his shoulder, and he\nheld in his hand a flaming torch. His every lineament bespoke a\ncelestial origin. The attempts to solve the enigma of this\npainting\u2014whose origin even was unknown\u2014though numerous, were all in\nvain, when one day a ship arriving from Rhodes, laden with works of art,\nbrought another picture, at once recognized as its companion. As before,\nthe Genius stood in the center, but the butterfly had disappeared, and\nthe torch was reversed and extinguished. The youths and maidens were no\nlonger sad and submissive, their mutual embraces announcing their entire\nemancipation from restraint. Still unable to solve the riddle, Dionysius\nsent the pictures to the Pythagorean sage, Epicharmus. After gazing upon\nthem long and earnestly, he said: Sixty years long have I pondered on\nthe internal springs of nature, and on the differences inherent in\nmatter; but it is only this day that the Rhodian Genius has taught me to\nsee clearly that which before I had only conjectured. In inanimate\nnature, everything seeks its like. Everything, as soon as formed,\nhastens to enter into new combinations, and nought save the disjoining\nart of man can present in a separate state ingredients which ye would\nvainly seek in the interior of the earth or in the moving oceans of air\nand water. Different, however, is the blending of the same substances in\nanimal and vegetable bodies. Here vital force imperatively asserts its\nrights, and heedless of the affinity and antagonism of the atoms, unites\nsubstances which in inanimate nature ever flee from each other, and\nseparates that which is incessantly striving to unite. Recognize,\ntherefore, in the Rhodian Genius, in the expression of his youthful\nvigor, in the butterfly on his shoulder, in the commanding glance of his\neye, the symbol of vital force as it animates every germ of organic\ncreation. The earthly elements at his feet are striving to gratify their\nown desires and to mingle with one another. Imperiously the Genius\nthreatens them with upraised and high-flaming torch, and compels them\nregardless of their ancient rights, to obey his laws. Look now on the\nnew work of art; turn from life to death. The butterfly has soared\nupward, the extinguished torch is reversed, and the head of the youth is\ndrooping; the spirit has fled to other spheres, and the vital force is\nextinct. Now the youths and maidens join their hands in joyous accord.\nEarthly matter again resumes its rights. Released from all bonds, they\nimpetuously follow their natural instincts, and the day of his death is\nto them a day of nuptials.[1]\n\nThe view here put by Humboldt into the mouth of Epicharmus may be taken\nas a fair representation of the current opinion of all ages concerning\nvital force. To-day, as truly as seventy-five years ago when Humboldt\nwrote, the mysterious and awful phenomena of life are commonly\nattributed to some controlling agent residing in the organism\u2014to some\nindependent presiding deity, holding it in absolute subjection. Such a\nnotion it was which prompted Heraclitus to talk of a universal fire, Van\nHelmont to propose his Arch\u00e6us, Hofmann his vital fluid, Hunter his\n_materia vit\u00e6 diffusa_, and Humboldt his vital force.[2] All these names\nassume the existence of a material or immaterial something, more or less\nseparable from the material body, and more or less identical with the\nmind or soul, which is the cause of the phenomena of living beings. But\nas science moved irresistibly onward, and it became evident that the\nforces of inorganic nature were neither deities nor imponderable fluids,\nseparable from matter, but were simple affections of it, analogy\ndemanded a like concession in behalf of vital force.[3] From the notion\nthat the effects of heat were due to an imponderable fluid called\ncaloric, discovery passed to the conviction that heat was but a motion\nof material particles, and hence inseparable from matter. To a like\nassumption concerning vitality it was now but a step. The more advanced\nthinkers in science of to-day, therefore, look upon the life of the\nliving form as inseparable from its substance, and believe that the\nformer is purely phenomenal, and only a manifestation of the latter.\nDenying the existence of a special vital force as such, they retain the\nterm only to express the sum of the phenomena of living beings.\n\nIn calling your attention this evening to the Correlation of the\nPhysical and the Vital Forces, I have a twofold object in view. On the\none hand, I would seek to interest you in a comparatively recent\ndiscovery of Science, and one which is destined to play a most important\npart in promoting man\u2019s welfare; and on the other I would inquire what\npart our own country has had in these discoveries.\n\nIn the first place, then, let us consider what the evidences are that\nvital and physical forces are correlated. Let us inquire how far\ninorganic and organic forces may be considered mutually convertible, and\nhence, in so far, mutually identical. This may best be done by\nconsidering, first, what is to be understood by correlation: and second,\nhow far are the physical forces themselves correlated to each other.\n\nAt the outset of our discussion, we are met by an unfortunate ambiguity\nof language. The word Force, as commonly used, has three distinct\nmeanings; in the first place, it is used to express the cause of motion,\nas when we speak of the force of gunpowder; it is also used to indicate\nmotion itself, as when we refer to the force of a moving cannon-ball;\nand lastly it is employed to express the effect of motion, as when we\nspeak of the blow which the moving body gives.[4] Because of this\nconfusion, it has been found convenient to adopt Rankine\u2019s\nsuggestion,[5] and to substitute the word \u2018energy\u2019 therefor. And\nprecisely as all force upon the earth\u2019s surface\u2014using the term force in\nits widest sense\u2014may be divided into attraction and motion, so all\nenergy is divided into potential and actual energy, synonymous with\nthose terms. It is the chemical attraction of the atoms, or their\npotential energy, which makes gunpowder so powerful; it is the\nattraction or potential energy of gravitation which gives the power to a\nraised weight. If now, the impediments be removed, the power just now\nlatent becomes active, attraction is converted into motion, potential\ninto actual energy, and the desired effect is accomplished. The energy\nof gunpowder or of a raised weight is potential, is capable of acting;\nthat of exploding gunpowder or of a falling weight is actual energy or\nmotion. By applying a match to the gunpowder, by cutting the string\nwhich sustains the weight, we convert potential into actual energy. By\npotential energy, therefore, is meant attraction; and by actual energy,\nmotion. It is in the latter sense that we shall use the word force in\nthis lecture; and we shall speak of the forces of heat, light,\nelectricity and mechanical motion, and of the attractions of\ngravitation, cohesion, chemism.\n\nFrom what has now been said, it is obvious that when we speak of the\nforces of heat, light, electricity or motion, we mean simply the\ndifferent modes of motion called by these names. And when we say that\nthey are correlated to each other, we mean simply that the mode of\nmotion called heat, light, electricity, is convertible into any of the\nothers, at pleasure. Correlation therefore implies convertibility, and\nmutual dependence and relationship.\n\nHaving now defined the use of the term force, and shown that forces are\ncorrelated which are convertible and mutually dependent, we go on to\nstudy the evidences of such correlation among the motions of inorganic\nnature usually called physical forces; and to ask what proof science can\nfurnish us that mechanical motion, heat, light, and electricity are thus\nmutually convertible. As we have already hinted, the time was when these\nforces were believed to be various kinds of imponderable matter, and\nchemists and physicists talked of the union of iron with caloric as they\ntalked of its union with sulphur, regarding the caloric as much a\ndistinct and inconvertible entity as the iron and sulphur themselves.\nGradually, however, the idea of the indestructibility of matter extended\nitself to force. And as it was believed that no material particle could\never be lost, so, it was argued, no portion of the force existing in\nnature can disappear. Hence arose the idea of the indestructibility of\nforce. But, of course, it was quite impossible to stop here. If force\ncannot be lost, the question at once arises, what becomes of it when it\npasses beyond our recognition? This question led to experiment, and out\nof experiment came the great fact of force-correlation; a fact which\ndistinguished authority has pronounced the most important discovery of\nthe present century.[6] These experiments distinctly proved that when\nany one of these forces disappeared, another took its place; that when\nmotion was arrested, for example, heat, light or electricity was\ndeveloped. In short, that these forces were so intimately related or\ncorrelated\u2014to use the word then proposed by Mr. Grove[7]\u2014that when one\nof them vanished, it did so only to reappear in terms of another. But\none step more was necessary to complete this magnificent theory. What\ncan produce motion but motion itself? Into what can motion be converted,\nbut motion? May not these forces, thus mutually convertible, be simply\ndifferent modes of motion of the molecules of matter, precisely as\nmechanical motion is a motion of its mass? Thus was born the dynamic\ntheory of force, first brought out in any completeness by Mr. Grove, in\n1842, in a lecture on the \u201cProgress of Physical Science,\u201d delivered at\nthe London Institution. In that lecture he said: \u201cLight, heat,\nelectricity, magnetism, motion, are all convertible material affections.\nAssuming either as the cause, one of the others will be the effect. Thus\nheat may be said to produce electricity, electricity to produce heat;\nmagnetism to produce electricity, electricity magnetism; and so of the\nrest.\u201d[8]\n\nA few simple experiments will help us to fix in our minds the great fact\nof the convertibility of force. Starting with actual visible motion,\ncorrelation requires that when it disappears as motion, it should\nreappear as heat, light, or electricity. If the moving body be elastic\nlike this rubber ball, then its motion is not destroyed when it strikes,\nbut is only changed in direction. But if it be non-elastic, like this\nball of lead, then it does not rebound; its motion is converted into\nheat. The motion of this sledge-hammer, for example, which if received\nupon this anvil would be simply changed in direction, if allowed to fall\nupon this bar of lead, is converted into heat; the evidence of which is\nthat a piece of phosphorus placed upon the lead is at once inflamed. So\ntoo, if motion be arrested by the cushion of air in this cylinder, the\nheat evolved fires the tinder carried in the plunger. But it is not\nnecessary that the arrest of motion should be sudden; it may be gradual,\nas in the case of friction. If this cylinder containing water or alcohol\nbe caused to revolve rapidly between the two sides of this wooden\nrubber, the heat due to the arrested motion will raise the temperature\nof the liquid to the boiling point, and the cork will be expelled. But\nmotion may also be converted into electricity. Indeed electricity is\nalways the result of friction between heterogeneous particles.[9] When\nthis piece of hard rubber, for example, is rubbed with the fur of a cat,\nit is at once electrified; and now if it be caused to communicate a\nportion of its charge to this glass plate, to which at the same time we\nadd the mechanical motion of rotation, the strong sparks produced give\nevidence of the conversion.\n\nSo, too, taking heat as the initial force, motion, light, electricity\nmay be produced. In every steam-engine the steam which leaves the\ncylinder is cooler than that which entered it, and cooler by exactly the\namount of work done. The motion of the piston\u2019s mass is precisely that\nlost by the steam molecules which batter against it. The conversion of\nheat into electricity, too, is also easily effected. When the junction\nof two metals is heated, electricity is developed. If the two metals be\nbismuth and antimony, as represented in this diagram, the currents flow\nas indicated by the arrows; and by multiplying the number of pairs, the\neffect may be proportionately increased. Such an arrangement, called a\nthermo-electric battery, we have here; and by it the heat of a single\ngas-burner may be made to move, when converted, this little electric\nbell-engine. Moreover, heat and light have the very closest analogy;\nexalt the rapidity with which the molecules move and light appears, the\ndifference being only one of intensity.\n\nAgain, if electricity be our starting point, we may accomplish its\nconversion into the other forces. Heat results whenever its passage is\ninterrupted or resisted; a wire of the poorly conducting metal platinum\nbecoming even red-hot by the converted electricity. To produce light, of\ncourse, we need only to intensify this action; the brightest artificial\nlight known, results from a direct conversion of electricity.\n\nEnough has now been said to establish our point. What is to be\nparticularly observed of these pieces of apparatus is that they are\nmachines especially designed for the conversion of some one force into\nanother. And we expect of them only that conversion. We pass on to\nconsider for a moment the quantitative relations of this mutual\nconvertibility. We notice, in the first place, that in all cases save\none, the conversion is not perfect, a part of the force used not being\nutilized, on the one hand, and on the other, other forces making their\nappearance simultaneously. While, for example, the conversion of motion\ninto heat is quite complete, the inverse conversion is not at all so.\nAnd on the other hand, when motion is converted into electricity, a part\nof it appears as heat. This simultaneous production of many forces is\nwell illustrated by our little bell-engine, which converts the\nelectricity of the thermo-battery into magnetism, and this into motion,\na part of which expends itself as sound. For these reasons the question\n\u201cHow much?\u201d is one not easily answered in all cases. The best known of\nthese relations is that between motion and heat, which was first\nestablished by Mr. Joule in 1849, after seven years of patient\ninvestigation.[10] The apparatus which he used is shown in the diagram.\nIt consists of a cylindrical box of metal, through the cover of which\npasses a shaft, carrying upon its lower end a set of paddles, immersed\nin water within the box, and upon its upper portion a drum, on which are\nwound two cords, which, passing in opposite directions, run over\npulleys, and are attached to known weights. The temperature of the water\nwithin the box being carefully noted, the weights are then allowed to\nfall a certain number of times, of course in their fall turning the\npaddles against the friction of the liquid. At the close of the\nexperiment the water is found to be warmer than before. And by measuring\nthe amount of this rise in temperature, knowing the distance through\nwhich the weights have fallen, it is easy to calculate the quantity of\nheat which corresponds to a given amount of motion. In this way, and as\na mean of a large number of experiments, Mr. Joule found that the amount\nof mass motion in a body weighing one pound, which had fallen from a\nhight of 772 feet, was exactly equal to the molecular motion which must\nbe added to a pound of water, in order to heat it one degree Fahrenheit.\nIf we call the actual energy of a body weighing one pound which has\nfallen one foot, a foot-pound, then we may speak of the mechanical\nequivalent of heat as being 772 foot-pounds.\n\nThe significance and value of this numerical constant will appear more\nclearly if we apply it to the solution of one or two simple problems.\nDuring the recent war two immense iron guns were cast in Pittsburgh,\nwhose weight was nearly 112,000 pounds each, and which had a caliber of\n20 inches.[11] Upon this diagram is a calculation of the effective blow\nwhich the solid shot of such a gun, assuming its weight to be 1,000\npounds and its velocity 1,100 feet per second, would give; it is 902,797\ntons![12] Now, if it were possible to convert the whole of this enormous\nmechanical power into heat, to how much would it correspond? This\nquestion may be answered by the aid of the mechanical equivalent of\nheat; here is the calculation, from which we see that when 17 gallons of\nice-cold water are heated to the boiling point, as much energy is\ncommunicated as is contained in the death-dealing missile at its highest\nvelocity.[13] Again, if we take the impact of a larger cannon-ball, our\nearth, which is whirling through space with a velocity of 19 miles a\nsecond, we find it to be 98,416,136,000,000,000,000,000,000,000,000\ntons![14] Were this energy all converted into heat, it would equal that\nproduced by the combustion of 14 earths of solid coal.[15]\n\nThe conversion of heat into motion, however, as already stated, is not\nas perfect. The best steam-engines economize only one-twentieth of the\nheat of the fuel.[16] Hence if a steamship require 600 tons of coal to\ncarry her across the Atlantic, 570 tons will be expended in heating the\nwaters of the ocean, the heat of the remaining 30 tons only being\nconverted into work.\n\nOne other quantitative determination of force has also been made. Prof.\nJulius Thomsen, of Copenhagen, has fixed experimentally the mechanical\nequivalent of light.[17] He finds that the energy of the light of a\nspermaceti candle burning 126\u00bd grains per hour, is equal in mechanical\nvalue to 13\u00b71 foot-pounds per minute. The same conclusion has been\nreached by Mr. Farmer, of Boston, from different data.[18]\n\nIf we pass from the actual physical energies or motions to consider for\na moment the potential energies or attractions, we find, also, an\nintimate correlation. Since all energy not active in motion is potential\nin attraction, it follows that in the attractions we have energy stored\nup for subsequent use. The sun is thus storing up energy: every minute\nit raises 2,000,000,000 tons of water to the mean hight of the clouds,\n3\u00bd miles; and the actual energy set free when this water falls is equal\nto 2,757,000,000,000 horse-powers.[19] So when the oxygen and the zinc\nof the ore are separated in the furnace, the actual energy of heat\nbecomes the potential energy of chemical attraction, which again becomes\nactual in the form of electricity when the zinc is dissolved in an acid.\nWe see, then, that not only may any form of force or actual energy be\nstored up as any form of attraction or potential energy, but that the\nlatter, from whatsoever source derived, may appear as heat, light,\nelectricity, or mechanical motion.\n\nHaving now established the fact of correlation for the physical forces,\nwe have next to inquire what are the evidences of the correlation of the\nvital forces with them. But in the first place it must be remarked that\nlife is not a simple term like heat or electricity; it is a complex\nterm, and includes all those phenomena which a living body exhibits. In\nthis discussion, therefore, we shall use the term vital force to express\nonly the actual energy of the body, however manifested. As to the\nattractions or the potential energy of the organism, nothing is more\nfully settled in science than the fact that these are precisely the same\nwithin the body as without it. Every particle of matter within the body\nobeys implicitly the laws of the chemical and physical attractions. No\noverpowering or supernatural agency comes in to complicate their action,\nwhich is modified only by the action of the others. Vitality, therefore,\nis the sum of the energies of a living body, both potential and actual.\n\nMoreover, the important fact must be fully recognized that in living\nbeings we have to do with no new elementary forms of matter. Precisely\nthe same atoms which build up the inorganic fabric, compose the organic.\nIn the early days of chemistry, indeed, it was supposed that the\ncomplicated molecules which life produced were beyond the reach of\nsimple chemical law. But as more and more complex molecules have been,\none after another, produced, chemistry has become re-assured, and now\ndoubts not her ability to produce them all. A few years hence, and she\nwill doubtless give us quinine and protagon, as she now gives us\ncoumarin and neurine, substances the synthesis of which was but\nyesterday an impossibility.[20]\n\nIn studying the phenomena of living beings, it is important also to bear\nin mind the different and at the same time the co\u00f6rdinate purposes\nsubserved by the two great kingdoms of nature. The food of the plant is\nmatter whose energy is all expended; it is a fallen weight. But the\nplant-organism receives it, exposes it to the sun\u2019s ray, and, in a way\nyet mysterious to us, converts the actual energy of the sunlight into\npotential energy within it. The fallen weight is thus raised, and energy\nis stored up in substances which now are alone competent to become the\nfood of the animal. This food is not such because any new atoms have\nbeen added to it; it is food because it contains within it potential\nenergy, which at any time may become actual as force. This food the\nanimal now appropriates; he brings it in contact with oxygen, and the\npotential energy becomes actual; he cuts the string, the weight falls,\nand what was just now only attraction, has become actual force; this\nforce he uses for his own purposes, and hands back the oxidized matter,\nthe fallen weight, to the plant to be again de-oxidized, to be again\nraised. The plant then is to be regarded as a machine for converting\nsunlight into potential energy; the animal, a machine for setting the\npotential energy free as actual, and economizing it. The force which the\nplant stores up is undeniably physical; must not the force which the\nanimal sets free by its conversion, be intimately correlated to it?\n\nBut approaching our question still more closely, let us, in illustration\nof the vital forces of the animal economy, choose three forms of its\nmanifestation in which to seek for the evidences of correlation; these\nshall be heat, evolved within the body; muscular energy or motion; and\nlastly, nervous energy, or that form of force which, on the one hand,\nstimulates a muscle to contract, and on the other, appears in forms\ncalled mental.\n\nThe heat which is produced by the living body is obviously of the same\nnature as heat from any other source; it is recognized by the same\ntests, and may be applied for the same purposes. As to its origin, it is\nevident that since potential energy exists in the food which enters the\nbody, and is there converted into force, a portion of it may become the\nactual energy of heat. And since, too, the heat produced in the body is\nprecisely such as would be set free by the combustion of this food\noutside of it, it is fair to assume that it thus originates. To this may\nbe added the chemical argument that while food capable of yielding heat\nby combustion is taken into the body, its constituents are completely or\nalmost completely, oxidized before leaving it; and since oxidation\nalways evolves heat, the heat of the body must have its origin in the\noxidation of the food. Moreover, careful measurements have demonstrated\nthat the amount of heat given off by the body of a man weighing 180\npounds is about 2,500,000 units. Accurate calculations have shown, on\nthe other hand, that 288\u00b74 grams of carbon and 12\u00b756 grams of hydrogen\nare available in the daily food for the production of heat. If burned\nout of the body, these quantities of carbon and hydrogen would yield\n2,765,134 heat units. Burned within it, as we have just seen, 2,500,000\nunits appear as heat; the rest in other forms of energy.[21] We\nconceive, however, that no long argument is necessary to prove that\nanimal heat results from a conversion of energy within the body; or that\nthe vital force heat, is as truly correlated to the other forces as when\nit has a purely physical origin.\n\nThe belief that the muscular force exerted by an animal is created by\nhim is by no means confined to the very earliest ages of history.\nTraces of it appear to the careful observer even now, although, as Dr.\nFrankland says, science has proved that \u201can animal can no more\ngenerate an amount of force capable of moving a grain of sand than a\nstone can fall upward or a locomotive drive a train without fuel.\u201d[22]\nIn studying the characters of muscular action we notice, first, that,\nas in the case of heat, the force which it develops is in no wise\ndifferent from motion in inorganic nature. In the early part of the\nlecture, motion produced by the contraction of muscle, was used to\nshow the conversion of mass-force into molecular force. No one in this\nroom believes, I presume, that the result would have been at all\ndifferent, had the motion been supplied by a steam-engine or a\nwater-wheel. Again, food, as we have seen, is of value for the\npotential energy it contains, which may become actual in the body.\nLiebig, in 1842, asserted that for the production of muscular force,\nthe food must first be converted into muscular tissue,[23] a view\nuntil recently accepted by physiologists.[24] It has been conclusively\nshown, however, within a few years, that muscular force cannot come\nfrom the oxidation of its own substance, since the products of this\nmetamorphosis are not increased in amount by muscular exertion.[25]\nIndeed, reasoning from the whole amount of such products excreted, the\noxidation of the amount of muscle which they represent would furnish\nscarcely one-fifth of the mechanical force of the body. But while the\nproducts of tissue-oxidation do not increase with the increase of\nmuscular exertion, the amount of carbonic gas exhaled by the lungs is\nincreased in the exact ratio of the work done.[26] No doubt can be\nentertained, therefore, that the actual energy of the muscle is simply\nthe converted potential energy of the carbon of the food. A muscle,\ntherefore, like a steam-engine, is a machine for converting the\npotential energy of carbon into motion. But unlike a steam-engine, the\nmuscle accomplishes this conversion directly, the energy not passing\nthrough the intermediate stage of heat. For this reason, the muscle is\nthe most economical producer of mechanical force known. While no\nmachine whatever can transform all of the energy into motion\u2014the most\neconomical steam-engines utilizing only one-twentieth of the heat\u2014the\nmuscle is able to convert one-fifth of the energy of the food into\nwork.[27] The other four-fifths must, therefore, appear as heat.\nWhenever a muscle contracts, then, four times as much energy appears\nas heat as is converted into motion. Direct experiments by Heidenhain\nhave confirmed this, by showing that an important rise of temperature\nattends muscular contraction;[28] a fact, however, apparent to any one\nwho has ever taken active exercise. The work done by the animal body\nis of two sorts, internal and external. The former includes the action\nof the heart, of the respiratory muscles, and of those assisting the\ndigestive process. The latter refers to the useful work the body may\nperform. Careful estimates place the entire work of the body at about\n800 foot-tons daily; of which 450 foot-tons is internal, 350 foot-tons\nexternal work. And since the internal work ultimately appears as heat\nwithin the body, the actual loss of heat by the production of motion\nis the equivalent of the 350 foot-tons which represents external work.\nThis by a simple calculation will be found to be 250,000 heat units,\nalmost the precise amount by which the heat yielded by the food when\nburned without the body, exceeds that actually evolved by the\norganism. Moreover, while the total heat given off by the body is\n2,500,000 units, the amount of energy evolved as work is equal to\nabout 600,000 heat units; hence the amount of work done by a muscle is\nas above stated, one-fifth of the actual energy derivable from the\nfood. One point further. The law of correlation requires that the heat\nset free when a muscle in contracting does work, shall be less than\nwhen it effects nothing; this fact, too, has been experimentally\nestablished by Heidenhain.[29] So, again, when muscular contraction\ndoes not result in motion, as when one tries to raise a weight too\nheavy for him, the energy which would have appeared as work, takes the\nform of heat: a result deducible by the law of correlation from the\nsteam-engine.\n\nThe last of the so-called vital forces which we are to examine, is that\nproduced by the nerves and nervous centers. In the nerve which\nstimulates a muscle to contract, this force is undeniably motion, since\nit is propagated along this nerve from one extremity to the other. In\ncommon language, too, this idea finds currency in the comparison of this\nforce to electricity; the gray or cellular matter being the battery, the\nwhite or fibrous matter the conductors. That this force is not\nelectricity, however, Du Bois-Reymond has demonstrated by showing that\nits velocity is only 97 feet in a second, a speed equaled by the\ngreyhound and the race-horse.[30] In his opinion, the propagation of a\nnervous impulse is a sort of successive molecular polarization, like\nmagnetism. But that this agent is a force, as analogous to electricity\nas is magnetism, is shown not only by the fact that the transmission of\nelectricity along a nerve will cause the contraction of the muscle to\nwhich it leads, but also by the more important fact that the contraction\nof a muscle is excited by diminishing its normal electrical current;[31]\na result which could take place only with a stimulus closely allied to\nelectricity. Nerve-force, therefore, must be a transmuted potential\nenergy.\n\nWhat, now, shall we say of that highest manifestation of animal life,\nthought-power? Has the upper region called intelligence and reason, any\nrelations to physical force? This realm has not escaped the searching\ninvestigation of modern science; and although in it investigations are\nvastly more difficult than in any of the regions thus far considered,\nyet some results of great value have been obtained, which may help us to\na solution of our problem. It is to be observed at the outset that every\nexternal manifestation of thought-force is a muscular one, as a word\nspoken or written, a gesture, or an expression of the face; and hence\nthis force must be intimately correlated with nerve-force. These\nmanifestations, reaching the mind through the avenues of sense, awaken\naccordant trains of thought only when this muscular evidence is\nunderstood. A blank sheet of paper excites no emotion; even covered with\nAssyrian cuneiform characters, its alternations of black and white\nawaken no response in the ordinary brain. It is only when, by a frequent\nrepetition of these impressions, the brain-cell has been educated, that\nthese before meaningless characters awaken thought. Is thought, then,\nsimply a cell action which may or may not result in muscular\nexpression\u2014an action which originates new combinations of truth only,\nprecisely as a calculating machine evolves new combinations of figures?\nWhatever we define thought to be, this fact appears certain, that it is\ncapable of external manifestation by conversion into the actual energy\nof motion, and only by this conversion. But here the question arises,\nCan it be manifested inwardly without such a transformation of energy?\nOr is the evolution of thought entirely independent of the matter of the\nbrain? Experiments, ingenious and reliable, have answered this question.\nThe importance of the results will, I trust, warrant me in examining the\nmethods employed in these experiments somewhat in detail. Inasmuch as\nour methods for measuring minute amounts of electricity are very\nperfect, and the methods for the conversion of heat into electricity are\nequally delicate, it has been found that smaller differences of\ntemperature may be recognized by converting the heat into electricity,\nthan can be detected thermometrically. The apparatus, first used by\nMelloni in 1832,[32] is very simple, consisting first, of a pair of\nmetallic bars like those described in the early part of the lecture, for\neffecting the conversion of the heat; and second, of a delicate\ngalvanometer, for measuring the electricity produced. In the experiments\nin question one of the bars used was made of bismuth, the other of an\nalloy of antimony and zinc.[33] Preliminary trials having shown that any\nchange of temperature within the skull was soonest manifested externally\nin that depression which exists just above the occipital protuberance, a\npair of these little bars was fastened to the head at this point; and to\nneutralize the results of a general rise of temperature over the whole\nbody, a second pair, reversed in direction, was attached to the leg or\narm, so that if a like increase of heat came to both, the electricity\ndeveloped by one would be neutralized by the other, and no effect be\nproduced upon the needle unless only one was affected. By long practice\nit was ascertained that a state of mental torpor could be induced,\nlasting for hours, in which the needle remained stationary. But let a\nperson knock on the door outside the room, or speak a single word, even\nthough the experimenter remained absolutely passive, and the reception\nof the intelligence caused the needle to swing through 20 degrees.[34]\nIn explanation of this production of heat, the analogy of the muscle at\nonce suggests itself. No conversion of energy is complete; and as the\nheat of muscular action represents force which has escaped conversion\ninto motion, so the heat evolved during the reception of an idea, is\nenergy which has escaped conversion into thought, from precisely the\nsame cause. Moreover, these experiments have shown that ideas which\naffect the emotions, produce most heat in their reception; \u201ca few\nminutes\u2019 recitation to one\u2019s self of emotional poetry, producing more\neffect than several hours of deep thought.\u201d Hence it is evident that the\nmechanism for the production of deep thought, accomplishes this\nconversion of energy far more perfectly than that which produces simply\nemotion. But we may take a step further in this same direction. A\nmuscle, precisely as the law of correlation requires, develops less heat\nwhen doing work than when it contracts without doing it. Suppose, now,\nthat beside the simple reception of an idea by the brain, the thought is\nexpressed outwardly by some muscular sign. The conversion now takes two\ndirections, and in addition to the production of thought, a portion of\nthe energy appears as nerve and muscle-power; less, therefore, should\nappear as heat, according to our law of correlation. Dr. Lombard\u2019s\nexperiments have shown that the amount of heat developed by the\nrecitation to one\u2019s self of emotional poetry, was in every case less\nwhen that recitation was oral; _i.e._, had a muscular expression. These\nresults are in accordance with the well-known fact that emotion often\nfinds relief in physical demonstrations; thus diminishing the emotional\nenergy by converting it into muscular. Nor do these facts rest upon\nphysical evidence alone. Chemistry teaches that thought-force, like\nmuscle-force, comes from the food; and demonstrates that the force\nevolved by the brain, like that produced by the muscle, comes not from\nthe disintegration of its own tissue, but is the converted energy of\nburning carbon.[35] Can we longer doubt, then, that the brain, too, is a\nmachine for the conversion of energy? Can we longer refuse to believe\nthat even thought is, in some mysterious way, correlated to the other\nnatural forces? and this, even in face of the fact that it has never yet\nbeen measured?[36]\n\nI cannot close without saying a word concerning the part which our own\ncountry has had in the development of these great truths. Beginning with\nheat, we find that the material theory of caloric is indebted for its\noverthrow more to the distinguished Count Rumford than to any other one\nman. While superintending the boring of cannon at the Munich Arsenal\ntowards the close of the last century, he was struck by the large amount\nof heat developed, and instituted a careful series of experiments to\nascertain its origin. These experiments led him to the conclusion that\n\u201canything which any insulated body or system of bodies can continue to\nfurnish without limitation, cannot possibly be a material substance.\u201d\nBut this man, to whom must be ascribed the discovery of the first great\nlaw of the correlation of energy, was an American. Born in Woburn,\nMass., in 1753, he, under the name of Benjamin Thompson, taught school\nafterward at Concord, N. H., then called Rumford. Unjustly suspected of\ntoryism during our Revolutionary war, he went abroad and distinguished\nhimself in the service of several of the Governments of Europe. He did\nnot forget his native land, though she had treated him so unfairly; when\nthe honor of knighthood was tendered him, he chose as his title the name\nof the Yankee village where he had taught school, and was thenceforward\nknown as Count Rumford. And at his death, by founding a professorship in\nHarvard College, and donating a prize-fund to the American Academy of\nArts and Sciences at Boston, he showed his interest in her prosperity\nand advancement.[37] Nor has the field of vital forces been without\nearnest workers belonging to our own country. Professors John W.\nDraper[38] and Joseph Henry[39] were among its earliest explorers. And\nin 1851, Dr. J. H. Watters, now of St. Louis, published a theory of the\norigin of vital force, almost identical with that for which Dr.\nCarpenter, of London, has of late received so much credit. Indeed, there\nis some reason to believe that Dr. Watters\u2019s essay may have suggested to\nthe distinguished English physiologist the germs of his own theory.[40]\nA paper on this subject by Prof. Joseph Leconte, of Columbia, S. C.,\npublished in 1859, attracted much attention abroad.[41] The remarkable\nresults already given on the relation of heat to mental work, which thus\nfar are unique in science, we owe to Professor J. S. Lombard, of Harvard\nCollege;[42] the very combination of metals used in his apparatus being\ndevised by our distinguished electrical engineer, Mr. Moses G. Farmer.\nFinally, researches conducted by Dr. T. R. Noyes in the Physiological\nLaboratory of Yale College, have confirmed the theory that muscular\ntissue does not wear during action, up to the point of fatigue;[43] and\nother researches by Dr. L. H. Wood have first established the same great\ntruth for brain-tissue.[44] We need not be ashamed, then, of our part in\nthis advance in science. Our workers are, indeed, but few; but both they\nand their results will live in the records of the world\u2019s progress. More\nwould there be now of them were such studies more fostered and\nencouraged. Self-denying, earnest men are ready to give themselves up to\nthe solution of these problems, if only the means of a bare subsistence\nbe allowed them. When wealth shall foster science, science will increase\nwealth\u2014wealth pecuniary, it is true: but also wealth of knowledge, which\nis far better.\n\nIn looking back over the whole of this discussion, I trust that it is\npossible to see that the objects which we had in view at its\ncommencement have been more or less fully attained. I would fain believe\nthat we now see more clearly the beautiful harmonies of bounteous\nnature; that on her many-stringed instrument force answers to force,\nlike the notes of a great symphony; disappearing now in potential\nenergy, and anon reappearing as actual energy, in a multitude of forms.\nI would hope that this wonderful unity and mutual interaction of force\nin the dead forms of inorganic nature, appears to you identical in the\nliving forms of animal and vegetable life, which make of our earth an\nEden. That even that mysterious, and in many aspects awful, power of\nthought, by which man influences the present and future ages, is a part\nof this great ocean of energy. But here the great question rolls upon\nus, Is it only this? Is there not behind this material substance, a\nhigher than molecular power in the thoughts which are immortalized in\nthe poetry of a Milton or a Shakespeare, the art creations of a Michael\nAngelo or a Titian, the harmonies of a Mozart or a Beethoven? Is there\nreally no immortal portion separable from this brain-tissue, though yet\nmysteriously united to it? In a word, does this curiously-fashioned body\ninclose a soul, God-given and to God returning? Here Science veils her\nface and bows in reverence before the Almighty. We have passed the\nboundaries by which physical science is enclosed. No crucible, no subtle\nmagnetic needle can answer now our questions. No word but His who formed\nus, can break the awful silence. In presence of such a revelation\nScience is dumb, and faith comes in joyfully to accept that higher truth\nwhich can never be the object of physical demonstration.\n\n\n------------------------------------------------------------------------\n\n\n\n\n                         NOTES AND REFERENCES.\n\n\nFootnote 1:\n\n  HUMBOLDT, Views of Nature, Bohn\u2019s ed., London, 1850, p. 380. This\n  allegory did not appear in the first edition of the Views of Nature.\n  In the preface to the second edition the author gives the following\n  account of its origin: \u201cSchiller,\u201d he says, \u201cin remembrance of his\n  youthful medical studies, loved to converse with me, during my long\n  stay at Jena, on physiological subjects.\u201d * * * \u201cIt was at this period\n  that I wrote the little allegory on Vital Force, called The Rhodian\n  Genius. The predilection which Schiller entertained for this piece,\n  which he admitted into his periodical, _Die Horen_, gave me courage to\n  introduce it here.\u201d It was published in _Die Horen_ in 1795.\n\nFootnote 2:\n\n  HUMBOLDT, _op. cit._, p. 386. In his _Aphorismi ex doctrina\n  Physiologi\u00e6 chemic\u00e6 Plantarum_, appended to his _Flora Fribergensis\n  subterranea_, published in 1793, Humboldt had said \u201cVim internam, qu\u00e6\n  chymic\u00e6 affinitatis vincula resolvit, atque obstat, quominus elementa\n  corporum libere conjungantur, vitalem vocamus.\u201d \u201cThat internal force,\n  which dissolves the bonds of chemical affinity, and prevents the\n  elements of bodies from freely uniting, we call vital.\u201d But in a note\n  to the allegory above mentioned, added to the third edition of the\n  Views of Nature in 1849, he says: \u201cReflection and prolonged study in\n  the departments of physiology and chemistry have deeply shaken my\n  earlier belief in peculiar so-called vital forces. In the year 1797, *\n  * * I already declared that I by no means regarded the existence of\n  these peculiar vital forces as established.\u201d And again: \u201cThe\n  difficulty of satisfactorily referring the vital phenomena of the\n  organism to physical and chemical laws depends chiefly (and almost in\n  the same manner as the prediction of meteorological processes in the\n  atmosphere) on the complication of the phenomena, and on the great\n  number of the simultaneously acting forces as well as the conditions\n  of their activity.\u201d\n\nFootnote 3:\n\n  Compare HENRY BENCE JONES, Croonian Lectures on Matter and Force.\n  London, 1868, John Churchill & Sons.\n\nFootnote 4:\n\n  Ib., Preface, p. vi.\n\nFootnote 5:\n\n  RANKINE, W. J. M., Philosophical Magazine, Feb., 1853. Also Edinburgh\n  Philosophical Journal, July, 1855.\n\nFootnote 6:\n\n  ARMSTRONG, Sir WM. In his address as President of the British\n  Association for the Advancement of Science. Rep. Brit. Assoc., 1863,\n  li.\n\nFootnote 7:\n\n  GROVE, W. R., in 1842. Compare \u201cNature\u201d i, 335, Jan. 27, 1870. Also\n  Appleton\u2019s Journal, iii, 324, Mch. 19, 1870.\n\nFootnote 8:\n\n  Id., in Preface to The Correlation of Physical Forces, 4th ed.\n  Reprinted in The Correlation and Conservation of Forces, edited by E.\n  L. Youmans, p. 7. New York, 1865, D. Appleton & Co.\n\nFootnote 9:\n\n  Id., ib., Am. ed., p. 33 et seq.\n\nFootnote 10:\n\n  JOULE, J. P., Philosophical Transactions, 1850, p. 61.\n\nFootnote 11:\n\n  See American Journal of Science, II, xxxvii, 296, 1864.\n\nFootnote 12:\n\n  The work (W) done by a moving body is commonly expressed by the\n  formula W = MV^2, in which M, or the mass of the body, is equal to\n  w/2g; _i.e._, to the weight divided by twice the intensity of gravity.\n  The work done by our cannon-ball then, would be (1 \u00d7 (1100)^2)/(2 \u00d7\n  64\u2153) = 9,404\u00b714 foot-tons. If, further, we assume the resisting body\n  to be of such a character as to bring the ball to rest in moving \u00bc of\n  an inch, then the final pressure would be 9,404\u00b714 \u00d7 12 \u00d7 4 =\n  451,398\u00b77 tons. But since, \u201cin the case of a perfectly elastic body,\n  or of a resistance proportional to the advance of the center of\n  gravity of the impinging body from the point at which contact first\n  takes place, the final pressure (provided the body struck is perfectly\n  rigid) is double what would occur were the stoppage to occur at the\n  end of a corresponding advance against a uniform resistance,\u201d this\n  result must be multiplied by two; and we get (451,398\u00b77 \u00d7 2) 902,797\n  tons as the crushing pressure of the ball under these conditions.\n  Note: The author\u2019s thanks are due to his friends Pres. F. A. P.\n  Barnard and Mr. J. J. Skinner for suggestions on the relation of\n  impact to statical pressure.\n\nFootnote 13:\n\n  The unit of impact being that given by a body weighing one pound and\n  moving one foot a second, the impact of such a body falling from a\n  hight of 772 feet\u2014the velocity acquired being 222\u00bc feet per second\n  (=\u221a(2sg))\u2014would be 1 \u00d7 (222\u00bc)^2 = 49,408 units, the equivalent in\n  impact of one heat-unit. A cannon-ball weighing 1000 lbs. and moving\n  1100 feet a second would have an impact of (1100)^2 \u00d7 1000 =\n  1,210,000,000 units. Dividing this by 49,408, the quotient is 24489\n  heat units, the equivalent of the impact. The specific heat of iron\n  being \u00b71138, this amount of heat would raise the temperature of one\n  pound of iron 215.191\u00b0 F. (24,489 \u00d7 \u00b71138) or of 1000 pounds of iron\n  215\u00b0 F. 24489 pounds of water heated one degree, is equal to 136\u00bd\n  pounds, or 17 gallons U. S., heated 180 degrees; _i.e._, from 32\u00b0 to\n  212\u00b0 F.\n\nFootnote 14:\n\n  Assuming the density of the earth to be 5\u00b75, its weight would be\n  6,500,000,000,000,000,000,000 tons, and its impact\u2014by the formula\n  given above\u2014would be 1,025,000,000,000,000,000,000,000,000,000\n  foot-tons. Making the same supposition as in the case of our\n  cannon-ball, the final pressure would be that here stated.\n\nFootnote 15:\n\n  TYNDALL, J., Heat considered as a mode of Motion; Am. ed., p. 57, New\n  York, 1863.\n\nFootnote 16:\n\n  RANKINE (The Steam-engine and other prime Movers, London, 1866,) gives\n  the efficiency of Steam-engines as from 1-15th to 1-20th of the heat\n  of the fuel.\n\n  ARMSTRONG, Sir WM., places this efficiency at 1-10th as the maximum.\n  In practice, the average result is only 1-30th. Rep. Brit. Assoc.,\n  1863, p. liv.\n\n  HELMHOLTZ, H. L. F., says: \u201cThe best expansive engines give back as\n  mechanical work only eighteen per cent. of the heat generated by the\n  fuel.\u201d Interaction of Natural Forces, in Correlation and Conservation\n  of Forces, p. 227.\n\nFootnote 17:\n\n  THOMSEN, JULIUS, Poggendorff\u2019s Annalen, cxxv, 348. Also in abstract in\n  Am. J. Sci., II, xli, 396, May, 1866.\n\nFootnote 18:\n\n  American Journal of Science, II, xli, 214, March, 1866.\n\nFootnote 19:\n\n  In this calculation the annual evaporation from the ocean is assumed\n  to be about 9 feet. (See Dr. BUIST, quoted in Maury\u2019s Phys. Geography\n  of the Sea, New York, 1861, p. 11.) Calling the water-area of our\n  globe 150,000,000 square miles, the total evaporation in tons per\n  minute, would be that here given. Inasmuch as 30,000 pounds raised\n  one-foot high is a horse-power, the number of horse-powers necessary\n  to raise this quantity of water 3\u00bd miles in one minute is\n  2,757,000,000,000. This amount of energy is precisely that set free\n  again when this water falls as rain.\n\nFootnote 20:\n\n  Compare ODLING, WM., Lectures on Animal Chemistry, London, 1866. \u201cIn\n  broad antagonism to the doctrines which only a few years back were\n  regarded as indisputable, we now find that the chemist, like the\n  plant, is capable of producing from carbonic acid and water a whole\n  host of organic bodies, and we see no reason to question his ultimate\n  ability to reproduce all animal and vegetable principles whatsoever.\u201d\n  (p. 52.)\n\n  \u201cAlready hundreds of organic principles have been built up from their\n  constituent elements, and there is now no reason to doubt our\n  capability of producing all organic principles whatsoever in a similar\n  manner.\u201d (p. 58.)\n\n  Dr. Odling is the successor of Faraday as Fullerian Professor of\n  Chemistry in the Royal Institution of Great Britain.\n\nFootnote 21:\n\n  MARSHALL, JOHN, Outlines of Physiology, American edition, 1868, p.\n  916.\n\nFootnote 22:\n\n  FRANKLAND, EDWARD, On the Source of Muscular Power, Proc. Roy. Inst.,\n  June 8, 1866; Am. J. Sci., II, xlii, 393, Nov. 1866.\n\nFootnote 23:\n\n  LIEBIG, JUSTUS VON, Die organische Chemie in ihrer Anwendung auf\n  Physiologie und Pathologie, Braunschweig, 1842. Also in his Animal\n  Chemistry, edition of 1852 (Am. ed., p. 26), where he says \u201cEvery\n  motion increases the amount of organized tissue which undergoes\n  metamorphosis.\u201d\n\nFootnote 24:\n\n  Compare DRAPER, JOHN WM. Human Physiology.\n\n  PLAYFAIR, LYON, On the Food of Man in relation to his useful work,\n  Edinburgh, 1865. Proc. Roy. Inst., Apr. 28, 1865.\n\n  RANKE, Tetanus eine Physiologische Studie, Leipzig, 1865.\n\n  ODLING, _op. cit._\n\nFootnote 25:\n\n  VOIT, E., Untersuchungen \u00fcber den Einfluss des Kochsalzes, des\n  Kaffees, und der Muskelbewegungen auf den Stoffwechsel, Munich, 1860.\n\n  SMITH, E., Philosophical Transactions, 1861, 747.\n\n  FICK, A., and WISLICENUS, J., Phil. Mag., IV, xxxi, 485.\n\n  FRANKLAND, E., _loc. cit._\n\n  NOYES, T. R., American Journal Medical Sciences, Oct. 1867.\n\n  PARKES, E. A., Proceedings Royal Society, xv, 339; xvi, 44.\n\nFootnote 26:\n\n  SMITH, EDWARD, Philosophical Transactions, 1859, 709.\n\nFootnote 27:\n\n  Authorities differ as to the amount of energy converted by the\n  steam-engine. (See Note 16.) Compare MARSHALL, _op. cit._, p. 918.\n  \u201cWhilst, therefore, in an engine one-twentieth part only of the fuel\n  consumed is utilized as mechanical power, one-fifth of the food\n  absorbed by man is so appropriated.\u201d\n\nFootnote 28:\n\n  HEIDENHAIN, Mechanische Leistung W\u00e4rmeentwickelung und Stoffumsatz bei\n  der Muskelth\u00e4tigkeit, Breslau, 1864.\n\n  See also HAUGHTON, SAMUEL, On the Relation of Food to work, published\n  in \u201cMedicine in Modern Times,\u201d London, 1869, Macmillan & Co.\n\nFootnote 29:\n\n  HEIDENHAIN, _op. cit._ Also by FICK, Untersuchungen \u00fcber\n  Muskel-arbeit, Basel, 1867. Compare also \u201cNature,\u201d i, 159, Dec. 9,\n  1869.\n\nFootnote 30:\n\n  DU BOIS-REYMOND, EMIL, On the time required for the transmission of\n  volition and sensation through the nerves, Proc. Roy. Inst. Also in\n  Appendix to Bence Jones\u2019s Croonian lectures.\n\nFootnote 31:\n\n  MARSHALL, _op. cit._, p. 227.\n\nFootnote 32:\n\n  MELLONI, Ann. Ch. Phys., xlviii, 198.\n\n  See also NOBILI, Bibl. Univ., xliv, 225, 1830; lvii, 1, 1834.\n\nFootnote 33:\n\n  The apparatus employed is illustrated and fully described in\n  Brown-Sequard\u2019s Archives de Physiologie, i, 498, June, 1868. By it the\n  1-4000th of a degree Centigrade may be indicated.\n\nFootnote 34:\n\n  LOMBARD, J. S., New York Medical Journal, v, 198, June, 1867. [A part\n  of these facts were communicated to me directly by their discoverer.]\n\nFootnote 35:\n\n  WOOD, L. H., On the influence of Mental activity on the Excretion of\n  Phosphoric acid by the Kidneys. Proceedings Connecticut Medical\n  Society for 1869, p. 197.\n\nFootnote 36:\n\n  On this question of vital force, see LIEBIG, Animal Chemistry. \u201cThe\n  increase of mass in a plant is determined by the occurrence of a\n  decomposition which takes place in certain parts of the plant under\n  the influence of light and heat.\u201d\n\n  \u201cThe modern science of Physiology has left the track of Aristotle. To\n  the eternal advantage of science, and to the benefit of mankind it no\n  longer invents a _horror vacui_, a _quinta essentia_, in order to\n  furnish credulous hearers with solutions and explanations of\n  phenomena, whose true connection with others, whose ultimate cause is\n  still unknown.\u201d\n\n  \u201cAll the parts of the animal body are produced from a peculiar fluid\n  circulating in its organism, by virtue of an influence residing in\n  every cell, in every organ, or part of an organ.\u201d\n\n  \u201cPhysiology has sufficiently decisive grounds for the opinion that\n  every motion, every manifestation of force, is the result of a\n  transformation of the structure or of its substance; that every\n  conception, every mental affection, is followed by changes in the\n  chemical nature of the secreted fluids; that every thought, every\n  sensation is accompanied by a change in the composition of the\n  substance of the brain.\u201d\n\n  \u201cAll vital activity arises from the mutual action of the oxygen of the\n  atmosphere and the elements of the food.\u201d\n\n  \u201cAs, in the closed galvanic circuit, in consequence of certain changes\n  which an inorganic body, a metal, undergoes when placed in contact\n  with an acid, a certain something becomes cognizable by our senses,\n  which we call a current of electricity; so in the animal body, in\n  consequence of transformations and changes undergone by matter\n  previously constituting a part of the organism, certain phenomena of\n  motion and activity are perceived, and these we call life, or\n  vitality.\u201d\n\n  \u201cIn the animal body we recognize as the ultimate cause of all force\n  only one cause, the chemical action which the elements of the food and\n  the oxygen of the air mutually exercise on each other. The only known\n  ultimate cause of vital force, either in animals or in plants, is a\n  chemical process.\u201d\n\n  \u201cIf we consider the force which determines the vital phenomena as a\n  property of certain substances, this view leads of itself to a new and\n  more rigorous consideration of certain singular phenomena, which these\n  very substances exhibit, in circumstances in which they no longer make\n  a part of living organisms.\u201d\n\n  Also OWEN, RICHARD, (Derivative Hypothesis of Life and Species,\n  forming the 40th chapter of his Anatomy of Vertebrates, republished in\n  Am. J. Sci., II, xlvii, 33, Jan. 1869.) \u201cIn the endeavor to clearly\n  comprehend and explain the functions of the combination of forces\n  called \u2018brain,\u2019 the physiologist is hindered and troubled by the views\n  of the nature of those cerebral forces which the needs of dogmatic\n  theology have imposed on mankind.\u201d * *\n\n  \u201cReligion pure and undefiled, can best answer how far it is righteous\n  or just to charge a neighbor with being unsound in his principles who\n  holds the term \u2018life\u2019 to be a sound expressing the sum of living\n  phenomena; and who maintains these phenomena to be modes of force into\n  which other forms of force have passed, from potential to active\n  states, and reciprocally, through the agency of these sums or\n  combinations of forces impressing the mind with the ideas signified by\n  the terms \u2018monad,\u2019 \u2018moss,\u2019 \u2018plant,\u2019 or \u2018animal.\u2019\u201d\n\n  And HUXLEY, THOS. H., \u201cOn the Physical Basis of Life,\u201d University\n  Series, No. 1. College Courant, 1870.\n\n  _Per contra_, see the Address of Dr. F. A. P. Barnard, as retiring\n  President, before the Am. Assoc. for the Advancement of Science,\n  Chicago meeting, August, 1868. \u201cThought cannot be a physical force,\n  because thought admits of no measure.\u201d\n\n  GOULD, BENJ. APTHORP, Address as retiring President, before the\n  American Association at its Salem meeting, Aug., 1869.\n\n  BEALE, LIONEL S., \u201cProtoplasm, or Life, Matter, and Mind.\u201d London,\n  1870. John Churchill & Sons.\n\nFootnote 37:\n\n  For an excellent account of this distinguished man, see Youmans\u2019s\n  Introduction to the Correlation and Conservation of Forces, p. xvii.\n\nFootnote 38:\n\n  DRAPER, J. W., _loc. cit._\n\nFootnote 39:\n\n  HENRY, JOSEPH, Agric. Rep. Patent Office, 1857, 440.\n\nFootnote 40:\n\n  WATTERS, J. H., An Essay on Organic, or Life-force. Written for the\n  degree of Doctor of Medicine in the University of Pennsylvania,\n  Philadelphia, 1851. See also St. Louis Medical and Surgical Journal,\n  II, v, Nos. 3 and 4, 1868; Dec. 1868, and Nov. 10, 1869.\n\nFootnote 41:\n\n  LECONTE, JOSEPH, The Correlation of Physical, Chemical and Vital\n  Force, and the Conservation of Force in Vital Phenomena. American\n  Journal of Science, II, xxviii, 305, Nov. 1859.\n\nFootnote 42:\n\n  LOMBARD, J. S., _loc. cit._\n\nFootnote 43:\n\n  NOYES, T. R., _loc. cit._\n\nFootnote 44:\n\n  WOOD, L. H., _loc. cit._\n\n\n------------------------------------------------------------------------\n\n\n\n\n                     _AS REGARDS PROTOPLASM, ETC._\n\n\n\n\n------------------------------------------------------------------------\n\n\n\n\n                            PREFATORY NOTE.\n\n\nThe substance of the greater part of this paper, which has been in the\npresent form for some time, was delivered, as a lecture, at a\nConversazione of the Royal College of Physicians of Edinburgh, in the\nHall of the College, on the evening of Friday, the 30th of April last.\n\nIt will be found to support itself, so far as the facts are concerned,\non the most recent German physiological literature, as represented by\nRindfleisch, K\u00fchne, and especially Stricker, with which last, for the\nproduction of his \u201cHandbuch,\u201d there is associated every great\nhistological name in Germany.\n\n    EDINBURGH, _October, 1869_.\n\n\n\n\n------------------------------------------------------------------------\n\n\n\n\n                      AS REGARDS PROTOPLASM, ETC.\n\n\nIt is a pleasure to perceive Mr. Huxley open his clear little essay with\nwhat we may hold, perhaps, to be the manly and orthodox view of the\ncharacter and products of the French writer, Auguste Comte. \u201cIn applying\nthe name of \u2018the new philosophy\u2019 to that estimate of the limits of\nphilosophical inquiry which he\u201d (Professor Huxley), \u201cin common with many\nother men of science, holds to be just,\u201d the Archbishop of York\nconfounds, it seems, this new philosophy with the Positive philosophy of\nM. Comte; and thereat Mr. Huxley expresses himself as greatly\nastonished. Some of us, for our parts, may be inclined at first to feel\nastonished at Mr. Huxley\u2019s astonishment; for the school to which, at\nleast on the philosophical side, Mr. Huxley seems to belong, is even\nnotorious for its prostration before Auguste Comte, whom, especially, so\nfar as method and systematization are concerned, it regards as the\ngreatest intellect since Bacon. For such, as it was the opinion of Mr.\nBuckle, is understood to be the opinion also of Messrs. Grote, Bain, and\nMill. In fact, we may say that such is commonly and currently considered\nthe characteristic and distinctive opinion of that whole perverted or\ninverted reaction which has been called the _Revulsion_. That is to say,\nto give this word a moment\u2019s explanation, that the Voltaires and Humes\nand Gibbons having long enjoyed an immunity of sneer at man\u2019s blind\npride and wretched superstition\u2014at _his_ silly non-natural honor and\n_her_ silly non-natural virtue\u2014a reaction had set in, exulting in\npoetry, in the splendor of nature, the nobleness of man, and the purity\nof woman, from which reaction again we have, almost within the last\ndecennium, been revulsively, as it were, called back,\u2014shall we say by\nsome \u201cbolder\u201d spirits\u2014the Buckles, the Mills, &c.?\u2014to the old\nillumination or enlightenment of a hundred years ago, in regard to the\nweakness and stupidity of man\u2019s pretensions over the animality and\nmateriality that limit him. Of this revulsion, then, as said, a main\nfeature, especially in England, has been prostration before the vast\nbulk of Comte; and so it was that Mr. Huxley\u2019s protest in this\nreference, considering the philosophy he professed, had that in it to\nsurprise at first. But if there was surprise, there was also pleasure;\nfor Mr. Huxley\u2019s estimate of Comte is undoubtedly the right one. \u201cSo far\nas I am concerned,\u201d he says, \u201cthe most reverend prelate\u201d (the Archbishop\nof York) \u201cmight dialectically hew M. Comte in pieces as a modern Agag,\nand I should not attempt to stay his hand; for, so far as my study of\nwhat specially characterizes the Positive philosophy has led me, I find\ntherein little or nothing of any scientific value, and a great deal\nwhich is as thoroughly antagonistic to the very essence of science as\nanything in ultramontane Catholicism.\u201d \u201cIt was enough,\u201d he says again,\n\u201cto make David Hume turn in his grave, that here, almost within earshot\nof his house, an instructed audience should have listened without a\nmurmur while his most characteristic doctrines were attributed to a\nFrench writer of fifty years\u2019 later date, in whose dreary and verbose\npages we miss alike the vigor of thought and the exquisite clearness of\nstyle of the man whom I make bold to term the most acute thinker of the\neighteenth century\u2014even though that century produced Kant.\u201d\n\nOf the doctrines themselves which are alluded to here, I shall say\nnothing now; but of much else that is said, there is only to be\nexpressed a hearty and even gratified approval. I demur, to be sure, to\nthe exaltation of Hume over Kant\u2014high as I place the former. Hume, with\ninfinite fertility, surprised us, it may be said, perhaps, into\nattention on a great variety of points which had hitherto passed\nunquestioned; but, even on these points, his success was of an\ninterrupted, scattered and inconclusive nature. He set the world adrift,\nbut he set man too, reeling and miserable, adrift with it. Kant, again,\nwith gravity and reverence, desired to refix, but in purity and truth,\nall those relations and institutions which alone give value to\nexistence\u2014which alone _are_ humanity, in fact\u2014but which Hume, with\nlevity and mockery, had approached to shake. Kant built up again an\nentire new world for us of knowledge and duty, and, in a certain way,\neven belief; whereas Hume had sought to dispossess us of every support\nthat man as man could hope to cling to. In a word, with _at least_ equal\nfertility, Kant was, as compared with Hume, a graver, deeper, and, so to\nspeak, a more consecutive, more comprehensive spirit. Graces there were\nindeed, or even, it may be said, subtleties, in which Hume had the\nadvantage perhaps. He is still in England an unsurpassed master of\nexpression\u2014this, certainly, in his History, if in his Essays he somewhat\nbaffles his own self by a certain labored breadth of conscious fine\nwriting, often singularly inexact and infelicitous. Still Kant, with\nreference to his products, must be allowed much the greater importance.\nIn the history of philosophy he will probably always command as\ninfluential a place in the modern world as Socrates in the ancient;\nwhile, as probably, Hume will occupy at best some such position as that\nof Heraclitus or Protagoras. Hume, nevertheless, if equal to Kant, must,\nin view at once of his own subjective ability and his enormous\ninfluence, be pronounced one of the most important of writers. It would\nbe difficult to rate too high the value of his French predecessors and\ncontemporaries as regards purification of their oppressed and corrupt\ncountry; and Hume must be allowed, though with less call, to have\nsubserved some such function in the land we live in. In preferring Kant,\nindeed, I must be acquitted of an undue partiality; for all that\nappertains to personal bias was naturally, and by reason of early and\nnumerous associations, on the side of my countryman.\n\nDemurring, then, to Mr. Huxley\u2019s opinion on this matter, and postponing\nremark on the doctrines to which he alludes, I must express a hearty\nconcurrence with every word he utters on Comte. In him I too \u201cfind\nlittle or nothing of any scientific value.\u201d I too have been lost in the\nmere mirage and sands of \u201cthose dreary and verbose pages;\u201d and I\nacknowledge in Mr. Huxley\u2019s every word the ring of a genuine experience.\nM. Comte was certainly a man of some mathematical and scientific\nproficiency, as well as of quick but biased intelligence. A member of\nthe _Aufkl\u00e4rung_, he had seen the immense advance of physical science\nsince Newton, under, as is usually said, the method of Bacon; and, like\nHume, like Reid, like Kant, _who had all anticipated him in this_, he\nsought to transfer that method to the domain of mind. In this he failed;\nand though in a sociological aspect he is not without true glances into\nthe present disintegration of society and the conditions of it, anything\nof importance cannot be claimed for him. There is not a sentence in his\nbook that, in the hollow elaboration and windy pretentiousness of its\nbuild, is not an exact type of its own constructor. On the whole,\nindeed, when we consider the little to which he attained, the empty\ninflation of his claims, the monstrous and maniacal self-conceit into\nwhich he was _exalted_, it may appear, perhaps, that charity to M. Comte\nhimself, to say nothing of the world, should induce us to wish that both\nhis name and his works were buried in oblivion. Now, truly, that Mr.\nHuxley (the \u201ccall\u201d being for the moment his) has so pronounced himself,\nespecially as the facts of the case are exactly and absolutely what he\nindicates, perhaps we may expect this consummation not to be so very\nlong delayed. More than those members of the revulsion already\nmentioned, one is apt to suspect, will be anxious now to beat a retreat.\nNot that this, however, is so certain to be allowed them; for their\nestimate of M. Comte is a valuable element in the estimate of\nthemselves.\n\nFrankness on the part of Mr. Huxley is not limited to his opinion of M.\nComte; it accompanies us throughout his whole essay. He seems even to\ntake pride, indeed, in naming always and everywhere his object at the\nplainest. That object, in a general point of view, relates, he tells us,\nsolely to materialism, but with a double issue. While it is his declared\npurpose, in the first place, namely, to lead us into materialism, it is\nequally his declared purpose, in the second place, to lead us out of\nmaterialism. On the first issue, for example, he directly warns his\naudience that to accept the conclusions which he conceives himself to\nhave established on Protoplasm, is to accept these also: That \u201call vital\naction\u201d is but \u201cthe result of the molecular forces\u201d of the physical\nbasis; and that, by consequence, to use his own words to his audience,\n\u201cthe thoughts to which I am now giving utterance, and your thoughts\nregarding them, are but the expression of molecular changes in that\nmatter of life which is the source of our other vital phenomena.\u201d And,\nso far, I think, we shall not disagree with Mr. Huxley when he says that\n\u201cmost undoubtedly the terms of his propositions are distinctly\nmaterialistic.\u201d Still, on the second issue, Mr. Huxley asserts that he\nis \u201cindividually no materialist.\u201d \u201cOn the contrary, he believes\nmaterialism to involve grave philosophical error;\u201d and the \u201cunion of\nmaterialistic terminology with the repudiation of materialistic\nphilosophy\u201d he conceives himself to share \u201cwith some of the most\nthoughtful men with whom he is acquainted.\u201d In short, to unite both\nissues, we have it in Mr. Huxley\u2019s own words, that it is the single\nobject of his essay \u201cto explain how such a union is not only consistent\nwith, but necessitated by, sound logic;\u201d and that, accordingly, he will,\nin the first place, \u201clead us through the territory of vital phenomena to\nthe materialistic slough,\u201d while pointing out, in the second, \u201cthe sole\npath by which, in his judgment, extrication is possible.\u201d Mr. Huxley\u2019s\nessay, then, falls evidently into two parts; and of these two parts we\nmay say, further, that while the one\u2014that in which he leads us into\nmaterialism\u2014will be predominatingly physiological, the other\u2014or that in\nwhich he leads us out of materialism\u2014will be predominatingly\nphilosophical. Two corresponding parts would thus seem to be prescribed\nto any full discussion of the essay; and of these, in the present needs\nof the world, it is evidently the latter that has the more promising\ntheme. The truth is, however, that Mr. Huxley, after having exerted all\nhis strength in his first part to throw us into \u201cthe materialistic\nslough,\u201d by _clear necessity of knowledge_, only calls to us, in his\nsecond part, to come out of this slough again, on the somewhat _obscure\nnecessity of ignorance_. This, then, is but a lop-sided balance, where a\nscale in the air only seems to struggle vainly to raise its\nwell-weighted fellow on the ground. Mr. Huxley, in fact, possesses no\nremedy for materialism but what lies in the expression that, while he\nknows not what matter is in itself, he certainly knows that casualty is\nbut contingent succession; and thus, like the so-called \u201cphilosophy\u201d of\nthe Revulsion, Mr. Huxley would only mock us into the intensest\ndogmatism on the one side by a fallacious reference to the intensest\nscepticism on the other.\n\nThe present paper, then, will regard mainly Mr. Huxley\u2019s argument _for_\nmaterialism, but say what is required, at the same time, on his alleged\nargument\u2014which is merely the imaginary, or imaginative, impregnation of\nignorance\u2014_against_ it.\n\nFollowing Mr. Huxley\u2019s own steps in his essay, the course of his\npositions will be found to run, in summary, thus:\u2014\n\nWhat is meant by the physical basis of life is, that there is one kind\nof matter common to all living beings, and it is named protoplasm. No\ndoubt it may appear at first sight that, in the various kinds of living\nbeings, we have only _difference_ before us, as in the lichen on the\nrock and the painter that paints it,\u2014the microscopic animalcule or\nfungus and the Finner whale or Indian fig,\u2014the flower in the hair of a\ngirl and the blood in her veins, etc. Nevertheless, throughout these and\nall other diversities, there really exists a threefold _unity_\u2014a unity\nof faculty, a unity of form, and a unity of substance.\n\nOn the first head, for example, or as regards faculty, power, the\naction exhibited, there are but three categories of _human_\nactivity\u2014contractility, alimentation, and reproduction; and there are\nno fewer for the _lower_ forms of life, whether animal or vegetable.\nIn the nettle, for instance, we find the woody case of its sting lined\nby a granulated, semi-fluid layer, that is possessed of contractility.\nBut in this respect\u2014that is, in the possession of contractile\nsubstance\u2014other plants are as the nettle, and all animals are as\nplants. Protoplasm\u2014for the nettle-layer alluded to is protoplasm\u2014is\ncommon to the whole of them. The difference, in short between the\npowers of the lowest plant or animal and those of the highest is one\nonly of degree and not of kind.\n\nBut, on the second head, it is not otherwise in form, or manifested\nexternal appearance and structure. Not the sting only, but the whole\nnettle, is made up of protoplasm; and of all the other vegetables the\nnettle is but a type. Nor are animals different. The colorless\nblood-corpuscles in man and the rest are identical with the protoplasm\nof the nettle; and both he and they consisted at first only of an\naggregation of such. Protoplasm is the common constituent\u2014the common\norigin. At last, as at first, all that lives, and every part of all that\nlives, are but nucleated or unnucleated, modified or unmodified,\nprotoplasm.\n\nBut, on the third head, or with reference to unity of substance, to\ninternal composition, chemistry establishes this also. All forms of\nprotoplasm, that is, consist alike of carbon, hydrogen, oxygen, and\nnitrogen, and behave similarly under similar reagents.\n\nSo, now, a uniform character having in this threefold manner been proved\nfor protoplasm, what is its origin, and what its fate? Of these the\nlatter is not far to seek. The fate of protoplasm is death\u2014death into\nits chemical constituents; and this determines its origin also.\nProtoplasm can originate only in that into which it dies,\u2014the\nelements\u2014the carbon, hydrogen, oxygen, and nitrogen\u2014of which it was\nfound to consist. Hydrogen, with oxygen, forms water; carbon, with\noxygen, carbonic acid; and hydrogen, with nitrogen, ammonia. Similarly,\nwater, carbonic acid and ammonia form, in union, protoplasm. The\ninfluence of pre-existing protoplasm only determines combination in\n_its_ case, as that of the electric spark determines combination in the\ncase of water. Protoplasm, then, is but an aggregate of physical\nmaterials, exhibiting in combination\u2014only as was to be expected\u2014new\nproperties. The properties of water are not more different from those of\nhydrogen and oxygen than the properties of protoplasm are different from\nthose of water, carbonic acid, and ammonia. We have the same warrant to\nattribute the consequences to the premises in the one case as in the\nother. If, on the first stage of combination, represented by that of\nwater, _simples_ could unite into something so different from\nthemselves, why, on the second stage of combination, represented by that\nof protoplasm, should not _compounds_ similarly unite into something\nequally different from themselves? If the constituents are credited with\nthe properties _there_, why refuse to credit the constituents with the\nproperties _here_? To the constituents of protoplasm, in truth, any new\nelement, named vitality, has no more been added, than to the\nconstituents of water any new element, named aquosity. Nor is there any\nlogical halting place between this conclusion and the further and final\none: That all vital action whatever, intellectual included, is but the\nresult of the molecular forces of the protoplasm which displays it.\n\nThese sentences will be acknowledged, I think, fairly to represent Mr.\nHuxley\u2019s relative deliverances, and, consequently, as I may be allowed\nto explain again, the only important\u2014while much the larger\u2014part of the\nwhole essay. Mr. Huxley, that is, while devoting fifty paragraphs to our\nphysiological immersion in the \u201cmaterialistic slough,\u201d grants but\none-and-twenty towards our philosophical escape from it; the fifty\nbesides being, so to speak, in reality the wind, and the one-and-twenty\nonly the whistle for it. What these latter say, in effect, is no more\nthan this, that,\u2014matter being known not in itself but only in its\nqualities, and cause and effect not in their nexus but only in their\nsequence,\u2014matter may be spirit or spirit matter, cause effect or effect\ncause\u2014in short, for aught that Mr. Huxley more than phenomenally knows,\nthis may be that or that this, first second, or second first, but the\nconclusion shall be this, that he will lay out all our knowledge\nmaterially, and we may lay out all our ignorance immaterially\u2014if we\nwill. Which reasoning and conclusion, I may merely remark, come\nprecisely to this: That Mr. Huxley\u2014who, hoping yet to see each object (a\npin, say) not in its qualities but in _itself_, still, consistently\nantithetic, cannot believe in the extinction of fire by water or of life\nby the rope, for any _reason_ or for any _necessity_ that lies in the\nnature of the case, but simply for the habit of the thing\u2014has not yet\nput himself at home with the metaphysical categories of _substance_ and\n_casualty_; thanks, perhaps, to those guides of his whom we, the amusing\nBritons that we are, bravely proclaim \u201cthe foremost thinkers of the\nday\u201d!\n\nThe matter and manner of the whole essay are now fairly before us, and I\nthink that, with the approbation of the reader, its procedure,\ngenerally, may be described as an attempt to establish, not by any\ncomplete and systematic induction, but by a variety of partial and\nillustrative assertions, two propositions. Of these propositions the\nfirst is, That all animal and vegetable organisms are essentially alike\nin power, in form, and in substance; and the second, That all vital and\nintellectual functions are the properties of the molecular disposition\nand changes of the material basis (protoplasm) of which the various\nanimals and vegetables consist. In both propositions, the agent of proof\nis this same alleged material basis of life, or protoplasm. For the\nfirst of them, all animal and vegetable organisms shall be identified in\nprotoplasm; and for the second, a simple chemical analogy shall assign\nintellect and vitality to the molecular constituents of the protoplasm,\nin connection with which they are at least exhibited.\n\nIn order, then, to obtain a footing on the ground offered us, the first\nquestion we naturally put is, What is Protoplasm? And an answer to this\nquestion can be obtained only by a reference to the historical progress\nof the physiological cell theory.\n\nThat theory may be said to have wholly grown up since John Hunter wrote\nhis celebrated work \u2018On the Nature of the Blood,\u2019 etc. New growths, to\nHunter, depended on an exudation of the plasma of the blood, in which,\nby virtue of its own _plasticity_, vessels formed, and conditioned the\nfurther progress. The influence of these ideas seems to have still\nacted, even after a conception of the cell was arrived at. For starting\nelement, Schleiden required an intracellular plasma, and Schwann a\nstructureless exudation, in which minute granules, if not indeed already\npre-existent, formed, and by aggregation grew into nuclei, round which\nsingly the production of a membrane at length enclosed a cell. It was\nthen that, in this connection, we heard of the terms blastema and\ncyto-blastema. The theory of the vegetable cell was completed earlier\nthan that of the animal one. Completion of this latter, again, seems to\nhave been first effected by Schwann, after M\u00fcller had insisted on the\nanalogy between animal and vegetable tissue, and Valentin had\ndemonstrated a nucleus in the animal cell, as previously Brown in the\nvegetable one. But assuming Schwann\u2019s labor, and what surrounded it, to\nhave been a first stage, the wonderful ability of Virchow may be said to\nhave raised the theory of the cell fully to a second stage. Now, of this\nsecond stage, it is the dissolution or resolution that has led to the\nemergence of the word Protoplasm.\n\nThe body, to Virchow, constituted a free state of individual subjects,\nwith equal rights but unequal capacities. These were the cells, which\nconsisted each of an enclosing membrane, and an enclosed nucleus with\nsurrounding intracellular matrix or matter. These cells, further,\npropagated themselves, chiefly by partition or division; and the\nfundamental principle of the whole theory was expressed in the dictum,\n\u201c_Omnis cellula e cellul\u00e2_.\u201d That is, the nucleus, becoming gradually\nelongated, at last parted in the midst; and each half, acting as center\nof attraction to the surrounding intracellular matrix or contained\nmatter, stood forth as a new nucleus to a new cell, formed by division\nat length of the original cell.\n\nThe first step taken in resolution of this theory was completed by Max\nSchultze, preceded by Leydig. This was the elimination of an investing\nmembrane. Such membrane may, and does, ultimately form; but in the first\ninstance, it appears, the cell is naked. The second step in the\nresolution belongs perhaps to Br\u00fccke, though preceded by Bergmann, and\nthough Max Schultze, K\u00fchne, Haeckel, and others ought to be mentioned in\nthe same connection. This step was the elimination, or at least\nsubordination, of the nucleus. The nucleus, we are to understand now, is\nnecessary neither to the division nor to the existence of the cell.\n\nThus, then, stripped of its membrane, relieved of its nucleus, what now\nremains for the cell? Why, nothing but what _was_ the contained matter,\nthe intracellular matrix, and _is_\u2014Protoplasm.\n\nIn the application of this word itself, however, to the element in\nquestion, there are also a step or two to be noticed. The first step was\nDujardin\u2019s discovery of sarcode; and the second the introduction of the\nterm protoplasm as the name for the layer of the _vegetable_ cell that\nlined the cellulose, and enclosed the nucleus. Sarcode, found in certain\nof the lower forms of life, was a simple substance that exhibited powers\nof spontaneous contraction and movement. Thus, processes of such simple,\nsoft, contractile matter are protruded by the rhizopods, and locomotion\nby their means effected. Remak first extended the use of the term\nprotoplasm from the layer which bore that name in the vegetable cell to\nthe analogous element in the animal cell; but it was Max Schultze, in\nparticular, who, by applying the name to the intracellular matrix, or\ncontained matter, when divested of membrane, and by identifying this\nsubstance itself with sarcode, first fairly established protoplasm, name\nand thing, in its present prominence.\n\nIn this account I have necessarily omitted many subordinate and\nintervening steps in the successive establishment of the\n_contractility_, superior _importance_, and complete _isolation_ of this\nthing to which, under the name of protoplasm, Mr. Huxley of late has\ncalled such vast attention. Besides the names mentioned, there are\nothers of great eminence in this connection, such as Meyen, Siebold,\nReichert, Ecker, Henle, and K\u00f6lliker among the Germans; and among\nourselves, Beale and Huxley himself. John Goodsir will be mentioned\nagain.\n\nWe have now, perhaps, obtained a general idea of protoplasm. Br\u00fccke,\nwhen he talks of it as \u201cliving cell-body or elementary organism,\u201d comes\nvery near the leading idea of Mr. Huxley as expressed in his phrase,\n\u201cthe physiological basis, or matter, of life.\u201d Living cell-body,\nelementary organism, primitive living matter\u2014that, evidently, is the\nquest of Mr. Huxley. There is aqueous matter, he would say, perhaps,\ncomposed of hydrogen and oxygen, and it is the same thing whether in the\nrain-drop or the ocean; so, similarly, there is vital matter, which,\ncomposed of carbon, hydrogen, oxygen, and nitrogen, is the same thing\nwhether in cryptogams or in elephants, in animalcules or in men. What,\nin fact, Mr. Huxley seeks, probably, is living protein\u2014protein, so to\nspeak, struck into life. Just such appears to him to be the nature of\nprotoplasm, and in it he believes himself to possess at last _a living\nclay_ wherewith to build the whole organic world.\n\nThe question, What is Protoplasm? is answered, then; but, for the\nunderstanding of what is to follow, there is still one general\nconsideration to be premised.\n\nMr. Huxley\u2019s conception of protoplasm, as we have seen, is that of\nliving matter, living protein; what we may call, perhaps, elementary\nlife-stuff. Now, is it quite certain that Mr. Huxley is correct in this\nconception? Are we to understand, for example, that cells have now\ndefinitively vanished, and left in their place only a uniform and\nuniversal _matter_ of quite indefinite proportions? No; such an\nunderstanding would be quite wrong. Whatever may be the opinion of the\nadherents of the molecular theory of generation, it is certain that all\nthe great German histologists still hold by the cell, and can hardly\nopen their mouths without mention of it. I do not allude here to any\nspecial adherents of either nucleus or membrane, but to the most\nadvanced innovators in both respects; to such men as Schultze and Br\u00fccke\nand K\u00fchne. These, as we have seen, pretty well confine their attention,\nlike Mr. Huxley, to the protoplasm. But they do not the less on that\naccount talk of the cell. For them, it is only in cells that protoplasm\nexists. To their view, we cannot fancy protoplasm as so much matter in a\npot, in an ointment-box, any portion of which scooped out in an\near-picker would be so much life-stuff, and, though a part, quite as\ngood as the whole. This seems to be Mr. Huxley\u2019s conception, but it is\nnot theirs. A certain _measure_ goes with protoplasm to constitute it an\norganism to them, and worthy of their attention. They refuse to give\nconsideration to any mere protoplasm-_shred_ that may not have yet\nceased, perhaps, to exhibit all sign of contractility under the\nmicroscope, and demand a protoplasm-_cell_. In short, protoplasm is to\nthem still distributed into cells, and only that measure of protoplasm\nis cell that is adequate to the whole group of vital manifestations.\nBr\u00fccke, for example, of all innovators probably the most innovating, and\ndenying, or inclined to deny, both nucleus and membrane, does not\nhesitate, according to Stricker, to speak still of cells as\nself-complete organisms, that move and grow, that nourish and reproduce\nthemselves, and that perform specific function. \u201cOmnis cellula e\ncellul\u00e2,\u201d is the rubric they work under as much now as ever. The heart\nof a turtle, they say, is not a turtle; so neither is a protoplasm-shred\na protoplasm-cell.\n\nThis, then, is the general consideration which I think it necessary to\npremise; and it seems, almost of itself, to negate Mr. Huxley\u2019s\nreasonings in advance, for it warrants us in denying that physiological\nclay of which all living things are but bricks baked, Mr. Huxley\nintimates, and in establishing in its place cells as before\u2014living cells\nthat differ infinitely the one from the other, and so differ from the\nvery first moment of their existence. This consideration shall not be\nallowed to pre-termit, however, an examination of Mr. Huxley\u2019s own\nproofs, which will only the more and more avail to indicate the\ndifference suggested.\n\nThese proofs, as has been said, would, by means of the single fulcrum of\nprotoplasm, establish, first, the identity, and, second, the\nmateriality, of all vegetable and animal life. These are, shortly, the\ntwo propositions which we have already seen, and to which, in their\norder, we now pass.\n\nAll organisms, then, whether animal or vegetable, have been understood\nfor some time back to originate in and consist of cells; but the\nprogress of physiology has _seemed_ now to substitute for cells a single\nmatter of life, protoplasm; and it is here that Mr. Huxley sees his cue.\nMr. Huxley\u2019s very first word is the \u201cphysical basis or matter of life;\u201d\nand he supposes \u201cthat to many the idea that there is such a thing may be\nnovel.\u201d This, then, so far, is what is _new_ in Mr. Huxley\u2019s\ncontribution. He seems to have said to himself, if formerly the whole\nworld was thought kin in an \u201cideal\u201d or formal element, organization, I\nshall now finally complete this identification in a \u201cphysical\u201d or\nmaterial element, protoplasm. In short, what at this stage we are asked\nto witness in the essay is, the identification of all living beings\nwhatever in the identity of protoplasm. As there is a single matter,\nclay, which is the matter of all bricks, so there is a single matter,\nprotoplasm, which is the matter of all organisms. \u201cProtoplasm is the\nclay of the potter, which, bake it and paint it as he will, remains\nclay, separated by artifice, and not by nature, from the commonest brick\nor sun-dried clod.\u201d Now here I cannot help stopping a moment to remark\nthat Mr. Huxley puts emphatically his whole soul into this sentence, and\nevidently believes it to be, if we may use the word, a _clincher_. But,\nafter all, does it say much? or rather, does it say anything? To the\nquestion, \u201cOf what are you made?\u201d the answer, for a long time now, and\nby the great mass of human beings who are supposed civilized, has been\n\u201cDust.\u201d Dust, and the same dust, has been allowed to constitute us all.\nBut materialism has not on that account been the irresistible result.\nAttention hitherto\u2014and surely excusably, or even laudably in such a\ncase\u2014has been given not so much to the dust as to the \u201cpotter,\u201d and the\n\u201cartifice\u201d by which he could so transform, or, as Mr. Huxley will have\nit, _modify_ it. To ask us to say, instead of dust, clay, or even\nprotoplasm, is not to ask us for much, then, seeing that even to Mr.\nHuxley there still remain both the \u201cpotter\u201d and his \u201cartifice.\u201d\n\nBut to return: To Mr. Huxley, when he says all bricks, being made of\nclay, are the same thing, we answer, Yes, undoubtedly, if they are made\nof the same clay. That is, the bricks are identical if the clay is\nidentical; but, on the other hand, by as much as the clay differs will\nthe bricks differ. And, similarly, all organisms can be identified only\nif their composing protoplasm can be identified. To this stake is the\nargument of Mr. Huxley bound.\n\nThis argument itself takes, as we have seen, a threefold course: Mr.\nHuxley will prove his position in this place by reference, firstly, to\nunity of faculty; secondly, to unity of form; and thirdly, to unity of\nsubstance. It is this course of proof, then, which we have now to\nfollow, but taking the question of substance, as simplest, first, and\nthe others later.\n\nBy substance, Mr. Huxley understands the internal or chemical\ncomposition; and, with a mere reference to the action of reagents, he\nasserts the protoplasm of all living beings to be an identical\ncombination of carbon, hydrogen, oxygen, and nitrogen. It is for us to\nask, then, Are all samples of protoplasm identical, first, in their\nchemical composition, and, second, under the action of the various\nreagents?\n\nOn the first clause, we may say, in the first place, towards a proof of\ndifference which will only cumulate, I hope, that, even should we grant\nin all protoplasm an identity of chemical ingredients, what is called\n_Allotropy_ may still have introduced no inconsiderable variety. Ozone\nis not antozone, nor is oxygen either, though in chemical constitution\nall are alike. In the second place, again, we may say that, with\n_varying proportions_, the same component parts produce very various\nresults. By way of illustration, it will suffice to refer to such\ndifferent things as the proteids, gluten, albumen, fibrin, gelatine,\netc., compared with the urinary products, urea and uric acid; or with\nthe biliary products, glycocol, glycocolic acid, bili-rubin,\nbili-verdin, etc.; and yet all these substances, varying so much the one\nfrom the other, are, as protoplasm is, compounds of carbon, hydrogen,\noxygen, and nitrogen. But, in the third place, we are not limited to a\n_may say_; we can assert the fact that all protoplasm is not chemically\nidentical. All the tissues of the organism are called protoplasm by Mr.\nHuxley; but can we predicate chemical identity of muscle and bone, for\nexample? In such cases Mr. Huxley, it is true, may bring the word\n\u201cmodified\u201d into use; but the objection of modification we shall examine\nlater. In the mean time, we are justified, by Mr. Huxley\u2019s very\nargument, in regarding all organized tissues whatever as protoplasm; for\nif these tissues are not to be identified in protoplasm, we must suppose\ndenied what it was his one business to affirm. And it is against that\naffirmation that we point to the fact of much chemical difference\nobtaining among the tissues, not only in the _proportions_ of their\nfundamental elements, but also in the _addition_ (and proportions as\nwell) of such others as chlorine, sulphur, phosphorus, potash, soda,\nlime, magnesia, iron, etc. Vast differences vitally must be legitimately\nassumed for tissues that are so different chemically. But, in the fourth\nplace, we have the authority of the Germans for asserting that the cells\nthemselves\u2014and they now, to the most advanced, are only protoplasm\u2014do\ndiffer chemically, some being found to contain glycogen, some\ncholesterine, some protogon, and some myosin. Now such substances, let\nthe chemical analogy be what it may, must still be allowed to introduce\nchemical difference. In the last place, Mr. Huxley\u2019s analysis is an\nanalysis of _dead_ protoplasm, and indecisive, consequently, for that\nwhich lives. Mr. Huxley betrays sensitiveness in advance to this\nobjection; for he seeks to rise above the sensitiveness and the\nobjection at once by styling the latter \u201cfrivolous.\u201d Nevertheless the\nGermans say pointedly that it is unknown whether the same elements are\nto be referred to the cells after as before death. K\u00fchne does not\nconsider it proved that living muscle contains syntonin; yet Mr. Huxley\ntells us, in his Physiology, that \u201csyntonin is the chief constituent of\nmuscle and flesh.\u201d In general, we may say, according to Stricker, that\nall weight is put now on the examination of living tissue, and that the\ndifference is fully allowed between that and dead tissue.\n\nOn the second clause now, or with regard to the action of reagents,\nthese must be denied to produce the like result on the various forms of\nprotoplasm. With reference to temperature, for example, K\u00fchne reports\nthe movements of the amoeba to be arrested in iced water; while, in the\nsame medium, the ova of the trout furrow famously, but perish even in a\nwarmed room. Others, again, we are told, may be actually dried, and yet\nlive. Of ova in general, in this connection, it is said that they live\nor die according as the temperature to which they are exposed differs\nlittle or much from that which is natural to the organisms producing\nthem. In some, according to Max Schultze, even distilled water is enough\nto arrest movement. Now, not to dwell longer here, both amoeba and ova\nare to Mr. Huxley pure protoplasm; and such difference of result,\naccording to difference of temperature, etc., must assuredly be allowed\nto point to a difference of original nature. Any conclusion so far,\nthen, in regard to unity of substance, whether the chemical composition\nor the action of reagents be considered, cannot be said to bear out the\nviews of Mr. Huxley.\n\nWhat now of the unities of form and power in protoplasm? By form, Mr.\nHuxley will be found to mean the general appearance and structure; and\nby faculty or power, the action exhibited. Now it will be very easy to\nprove that, in neither respect, do all specimens of protoplasm agree.\nMr. Huxley\u2019s representative protoplasm, it appears, is that of the\nnettle-sting; and he describes it as a granulated, semi-fluid body,\ncontractile in mass, and contractile also in detail to the development\nof a species of circulation. Stricker, again, speaks of it as a\nhomogeneous substance, in which any granules that may appear must be\nconsidered of foreign importation, and in which there are no evidences\nof circulation. In this last respect, then, that Mr. Huxley should talk\nof \u201ctiny Maelstroms,\u201d such as even in the silence of a tropical noon\nmight stun us, if heard, as \u201cwith the roar of a great city,\u201d may be\nviewed, perhaps, as a rise into poetry beyond the occasion.\n\nFurther, according to Stricker, protoplasm varies almost infinitely in\nconsistence, in shape, in structure, and in function. In consistence, it\nis sometimes so fluid as to be capable of forming in drops; sometimes\nsemi-fluid and gelatinous; sometimes of considerable resistance. In\nshape\u2014for to Stricker the cells are now protoplasm\u2014we have club-shaped\nprotoplasm, globe-shaped protoplasm, cup-shaped protoplasm,\nbottle-shaped protoplasm, spindle-shaped protoplasm\u2014branched, threaded,\nciliated protoplasm,\u2014circle-headed protoplasm\u2014flat, conical,\ncylindrical, longitudinal, prismatic, polyhedral, and palisade-like\nprotoplasm. In structure, again, it is sometimes uniform and sometimes\nreticulated into interspaces that contain fluid. In function, lastly\u2014and\nhere we have entered on the consideration of faculty or power\u2014some\nprotoplasm is vagrant (so to translate _wandernd_), and of unknown use,\nlike the colorless blood-corpuscles.\n\nIn reference to these, as strengthening the argument, and throwing much\nlight generally, I break off a moment to say that, very interesting as\nthey are in themselves, and as Recklinghausen, in especial, has made\nthem, Mr. Huxley\u2019s theory of them disagrees considerably with the\nprevalent German one. He speaks of them as the source of the body in\ngeneral, yet, in his Physiology, he talks of the spleen, the lymphatics,\nand even the liver\u2014_parts_ of the body\u2014as _their_ source. They are so\nfew in number that, while Mr. Huxley is thankful to be able to point to\nthe inside of the lips as a seat for them, they bear to the red\ncorpuscles only the proportion of 1 to 450. This disproportion, however,\nis no bar to Mr. Huxley\u2019s derivation of the latter from the former. But\nthe fact is questioned. The Germans, generally, for their, part,\ndescribe the colorless, or vagrant, blood-corpuscles as probably media\nof conjugation or reparation, but acknowledge their function to be as\nyet quite unknown; while Rindfleisch, characterizing the spleen as the\ngrave of the red, and the womb of the white, corpuscles, evidently\nrefers the latter to the former. This, indeed, is a matter of direct\nassertion with Preyer, who has \u201cshown that pieces of red\nblood-corpuscles may be eaten by the amoeboid cells of the frog,\u201d and\nholds that the latter (the white corpuscles) proceed directly from the\nformer (the red corpuscles); so that it seems to be determined in the\nmean time that there is no proof of the reverse being the fact.\n\nIn function, then, to resume, some protoplasm is vagrant, and of unknown\nuse. Some again produces pepsine, and some fat. Some at least contains\npigment. Then there is nerve-protoplasm, brain-protoplasm,\nbone-protoplasm, muscle-protoplasm, and protoplasm of all the other\ntissues, no one of which but produces only its own kind, and is\nuninterchangeable with the rest. Lastly, on this head, we have to point\nto the overwhelming fact that there is the infinitely different\nprotoplasm of the various infinitely different plants and animals, in\neach of which its own protoplasm, as in the case of that of the various\ntissues, but produces its own kind, and is uninterchangeable with that\nof the rest.\n\nIt may be objected, indeed, that these latter are examples of modified\nprotoplasm. The objection of modification, as said, we have to see by\nitself later; but, in the mean time, it may be asked, Where are we to\nbegin, _not_ to have modified protoplasm? We have the example of Mr.\nHuxley himself, who, in the nettle-sting, begins already with modified\nprotoplasm; and we have the authority of Rindfleisch for asserting that\n\u201cin every different tissue we must look for a different initial term of\nthe productive series.\u201d This, evidently, is a very strong light on the\noriginal multiplicity of protoplasm, which the consideration, as we have\nseen, of the various plants and animals, has made, further, infinite.\nThis is enough; but there is no wish to evade beginning with the very\nbeginning\u2014with absolutely pure initial protoplasm, if it can but be\ngiven us in any reference. The simple egg\u2014that, probably is the\nbeginning\u2014that, probably, is the original identity; yet even there we\nfind already distribution of the identity into infinite difference.\nThis, certainly, with reference to the various organisms, but with\nreference also to the various tissues. That we regard the egg as the\nbeginning, and that we do not start, like the smaller exceptional\nphysiological school, with molecules themselves, depends on this, that\nthe great Germans so often alluded to, K\u00fchne among them, still trust in\nthe experiments of Pasteur; and while they do not deny the possibility,\nor even the fact, of molecular generation, still feel justified in\ndenying the existence of any observation that yet unassailably attests a\n_generatio \u00e6quivoca_. By such authority as this the simple philosophical\nspectator has no choice but to take his stand; and therefore it is that\nI assume the egg as the established beginning, so far, of all vegetable\nand animal organisms. To the egg, too, as the beginning, Mr. Huxley,\nthough the lining of the nettle-sting is his representative protoplasm,\nat least refers. \u201cIn the earliest condition of the human organism,\u201d he\nsays, in allusion to the white (vagrant) corpuscles of the blood, \u201cin\nthat state in which it has but just become distinguished from the egg in\nwhich it arises, it is nothing but an aggregation of such corpuscles,\nand every organ of the body was once no more than such an aggregation.\u201d\nNow, in beginning with the egg\u2014an absolute beginning being denied us in\nconsequence of the pre-existent infinite difference of the egg or eggs\nthemselves\u2014we may gather from the German physiologists some such account\nof the actual facts as this.\n\nThe first change signalized in the impregnated egg seems that of\n_Furchung_, or furrowing\u2014what the Germans call the _Furchungskugeln_,\nthe _Dotterkugeln_, form. Then these _Kugeln_\u2014clumps, eminences,\nmonticles, we may translate the word\u2014break into cells; and these are the\ncells of the embryo. Mr. Huxley, as quoted, refers to the whole body,\nand every organ of the body, as at first but an aggregation of colorless\nblood-corpuscles; but in the very statement which would render the\nidentity alone explicit, the difference is quite as plainly implicit. As\nmuch as this lies in the word \u201corgans,\u201d to say nothing of \u201chuman.\u201d The\ncells of the \u201corgans,\u201d to which he refers, are even then\nuninterchangeable, and produce but themselves. The Germans tell us of\nthe _Keimblatt_, the germ-leaf, in which all these organs originate.\nThis _Blatt_, or leaf, is threefold, it seems; but even these folds are\nnot indifferent. The various cells have their distinct places in them\nfrom the first. While what in this connection are called the epithelial\nand endorthelial tissues spring respectively from the _upper_ and\n_under_ leaf, connective tissues, with muscle and blood, spring from the\n_middle_ one. Surely in such facts we have a perfect warrant to assert\nthe initial non-identity of protoplasm, and to insist on this, that,\nfrom the very earliest moment\u2014even literally _ab ovo_\u2014brain-cells only\ngenerate brain-cells, bone-cells bone-cells, and so on.\n\nThese considerations on function all concern faculty or power; but we\nhave to notice now that the characteristic and fundamental form of power\nis to Mr. Huxley _contractility_. He even quotes Goethe in proof of\ncontractility being the main power or faculty of _Man_! Nevertheless it\nis to be said at once that, while there are differences in what\nprotoplasm _is_ contractile, all protoplasm is not contractile, nor\ndependent on contractility for its functions. In the former respect, for\nexample, muscle, while it is the contractile tissue special, is also to\nMr. Huxley protoplasm; yet Stricker asserts the inner construction of\nthe contractile substance, of which muscle-fibre virtually consists, to\nbe essentially different from contractile protoplasm. Here, then, we\nhave the contractile _substance_ proper \u201cessentially different\u201d from the\ncontractile _source_ proper. In the latter respect, again, we shall not\ncall in the _un_contractible substances which Mr. Huxley himself\ndenominates protoplasm\u2014bread, namely, roast mutton, and boiled lobster;\nbut we may ask where\u2014even in the case of a living body\u2014is the\ncontractility of white of egg? In this reference, too, we may remark\nthat K\u00fchne, who divides the protoplasm of the epidermis into three\nclasses, has been unable to distinguish contractility in his own third\nclass. Lastly, where, in relation to the protoplasm of the nervous\nsystem, is there evidence of its contractility? Has any one pretended\nthat thought is but the contraction of the brain; or is it by\ncontraction that the very nerves operate contraction\u2014the nerves that\nsupply muscles, namely? Mr. Huxley himself, in his Physiology, describes\nnervous action very differently. There _conduction_ is spoken of without\na hint of contraction. Of the higher faculties of man I have to speak\nagain; but let us just ask where, in the case of any pure\nsensation\u2014smell, taste, touch, sound, color\u2014is there proof of any\ncontraction? Are we to suppose that between the physical cause of heat\nwithout and the mental sensation of heat within, contraction is anywhere\ninterpolated? Generally, in conclusion here, while reminding of\nVirchow\u2019s testimony to the inherent inequalities of cell-capacity, let\nus but, on the question of faculty, contrast the kidney and the brain,\neven as these organs are viewed by Mr. Huxley. To him the one is but a\nsieve for the extrusion of refuse: the other thinks Newton\u2019s \u2018Principia\u2019\nand Iliads of Homer.\n\nProbably, then, in regard to any continuity in protoplasm of power, of\nform, or of substance, we have seen _lacun\u00e6_ enow. Nay, Mr. Huxley\nhimself can be adduced in evidence on the same side. Not rarely do we\nfind in his essay admissions of _probability_ where it is _certainty_\nthat is alone in place. He says, for example, \u201cIt is more than probable\nthat _when_ the vegetable world _is_ thoroughly explored we _shall_ find\nall plants in possession of the same powers.\u201d When a conclusion is\ndecidedly announced, it is rather disappointing to be told, as here,\nthat the premises are still to collect. \u201c_So far_,\u201d he says again, \u201cas\nthe conditions of the manifestations of the phenomena of contractility\nhave _yet_ been studied.\u201d Now, such a _so far_ need not be _very far_;\nand we may confess in passing, that from Mr. Huxley the phrase, \u201cthe\nconditions of the _manifestations_ of the _phenomena_\u201d grates. We hear\nagain that it is \u201cthe rule _rather_ than the exception,\u201d or that\n\u201cweighty authorities have _suggested_\u201d that such and such things\n\u201cprobably occur,\u201d or, while contemplating the nettle-sting, that such\n\u201c_possible_ complexity\u201d in other cases \u201c_dawns_ upon one.\u201d On other\noccasions he expresses himself to the effect that \u201cperhaps it would not\nyet be safe to say that _all_ forms,\u201d etc. Nay, not only does he\ndirectly _say_ that \u201cit is by no means his intention to suggest that\nthere is no difference between the lowest plant and the highest, or\nbetween plants and animals,\u201d but he directly proves what he says, for he\ndemonstrates in plants and animals an _essential difference of power_.\nPlants _can_ assimilate inorganic matters, animals can _not_, etc.\nAgain, here is a passage in which he is seen to cut his own \u201c_basis_\u201d\nfrom beneath his own feet. After telling us that all forms of protoplasm\nconsist of carbon, hydrogen, oxygen, and nitrogen \u201cin very complex\nunion,\u201d he continues, \u201cTo this complex combination, _the nature of which\nhas never been determined with exactness_, the name of protein has been\napplied.\u201d This, plainly, is an identification, on Mr. Huxley\u2019s own part,\nof protoplasm and protein; and what is said of the one being necessarily\ntrue of the other, it follows that Mr. Huxley admits the nature of\nprotoplasm never to have been determined with exactness, and that, even\nin his eyes, the _lis_ is still _sub judice_. This admission is\nstrengthened by the words, too, \u201cIf we use this term\u201d (protein) \u201cwith\nsuch _caution_ as may properly arise out of our _comparative ignorance_\nof the things for which it stands;\u201d which entitle us to recommend, in\nconsequence \u201cof our _comparative ignorance_ of the things for which it\nstands,\u201d \u201c_caution_\u201d in the use of the term protoplasm. In such a state\nof the case we cannot wonder that Mr. Huxley\u2019s own conclusion here is:\nTherefore \u201call living matter is more or less albuminoid.\u201d All living\nmatter is more or less albuminoid! That, indeed, is the single\nconclusion of Mr. Huxley\u2019s whole industry; but it is a conclusion that,\nfar from requiring the intervention of protoplasm, had been reached long\nbefore the word itself had been, in this connection, used.\n\nIt is in this way, then, that Mr. Huxley can be adduced in refutation of\nhimself; and I think his resort to an epigram of Goethe\u2019s for reduction\nof the powers of man to those of contraction, digestion, and\nreproduction, can be regarded as an admission to the same effect. The\nepigram runs thus:\u2014\n\n   \u201cWarum treibt sich das Volk so, und schreit? Es will sich ern\u00e4hren,\n    Kinder zeugen, und die n\u00e4hren so gut es vermag.\n    Weiter bringt es kein Mensch, stell\u2019 er sich wie er auch will.\u201d\n\nThat means, quite literally translated, \u201cWhy do the folks bustle and\nbawl? They want to feed themselves, get children, and then feed them as\nbest they can; no man does more, let him do as he may.\u201d This, really, is\nMr. Huxley\u2019s sole proof for his classification of the powers of man. Is\nit sufficient? Does it not apply rather to the birds of the air, the\nfish of the sea, and the beasts of the field, than to man? Did Newton\nonly feed himself, beget children, and then feed them? Was it impossible\nfor him to do any more, let him do as he might? And what we ask of\nNewton we may ask of all the rest. To elevate, therefore, the passing\nwhim of mere literary _Laune_ into a cosmical axiom and a proof in\nplace\u2014this we cannot help adding to the other productions here in which\nMr. Huxley appears against himself.\n\nBut were it impossible either for him or us to point to these _lacun\u00e6_,\nit would still be our right and our duty to refer to the present\nconditions of microscopic science in general as well as in particular,\nand to demur to the erection of its _dicta_, constituted as they yet\nare, into established columns and buttresses in support of any theory of\nlife, material or other.\n\nThe most delicate and dubious of all the sciences, it is also the\nyoungest. In its manipulations the slightest change may operate as a\ndestructive drought, or an equally destructive deluge. Its very tools\nmay positively create the structure it actually examines. The present\nstate of the science, and what warrant it gives Mr. Huxley to dogmatize\non protoplasm, we may understand from this avowal of K\u00fchne\u2019s: \u201cTo-day we\nbelieve that we see\u201d such or such fact, \u201cbut know not that further\nimprovements in the means of observation will not reveal what is assumed\nfor certainty to be only illusion.\u201d With such authority to lean on\u2014and\nit is the highest we can have\u2014we may be allowed to entertain the\nconjecture, that it is just possible that some certainties, even of Mr.\nHuxley, may yet reveal themselves as illusions.\n\nBut, in resistance to any sweeping conclusions built on it, we are not\nconfined to a reference to the imperfections involved in the very nature\nand epoch of the science itself in general. With yet greater assurance\nof carrying conviction with us, we may point in particular to the actual\nopinions of its present professors. We have seen already, in the\nconsideration premised, that Mr. Huxley\u2019s hypothesis of a protoplasm\n_matter_ is unsupported, even by the most innovating Germans, who as yet\nwill not advance, the most advanced of them, beyond a protoplasm-cell;\nand that his whole argument is thus sapped in advance. But what\nthreatens more absolute extinction of this argument still, _all_ the\nGerman physiologists do _not_ accept even the protoplasm-cell.\nRindfleisch, for example, in his recently-published \u2018Lehrbuch der\npathologischen Gewebelehre\u2019 speaks of the cell very much as we\nunderstand Virchow to have spoken of it. To him there is in the cell not\nonly protoplasm but nucleus, and perhaps membrane as well. To him, too,\nthe cell propagates itself quite as we have been hitherto fancying it to\ndo, by division of the nucleus, increase of the protoplasm, and ultimate\npartition of the cell itself. Yet he knows withal of the opinions of\nothers, and accepts them in a manner. He mentions K\u00fchne\u2019s account of the\nmembrane as at first but a mere physical limit of two fluids\u2014a mere\nperipheral film or curdling; still he assumes a formal and decided\nmembrane at last. Even Leydig and Schultze, who shall be the express\neliminators of the membrane\u2014the one by initiation and the other by\nconsummation\u2014confess that, as regards the cells of certain tissues, they\nhave never been able to detect in them the absence of a membrane.\n\nAs regards the nucleus again, the case is very much stronger. When we\nhave admitted with Br\u00fccke that certain cryptogam cells, with Haeckel\nthat certain protists, with Cienkowsky that two monads, and with\nSchultze that one amoeba, are without nucleus\u2014when we have admitted that\ndivision of the cell _may_ take place without implicating that of the\nnucleus\u2014that the movements of the nucleus _may_ be passive and due to\nthose of the protoplasm\u2014that Baer and Stricker demonstrate the\ndisappearance of the original nucleus in the impregnated egg,\u2014when we\nhave admitted this, we have admitted also all that can be said in\ndegradation of the nucleus. Even those who say all this still attribute\nto the nucleus an important and unknown _r\u00f4le_, and describe the\nformation in the impregnated egg of a new nucleus; while there are\nothers again who resist every attempt to degrade it. B\u00f6ttcher asserts\nmovement for the nucleus, even when wholly removed from the cell;\nNeumann points to such movement in dead or dying cells; and there is\nother testimony to a like effect, as well as to peculiarities of the\nnucleus otherwise that indicate spontaneity. In this reference we may\nallude to the weighty opinion of the late Professor Goodsir, who\nanticipated in so remarkable a manner certain of the determinations of\nVirchow. Goodsir, in that anticipation, wonderfully rich and ingenious\nas he is everywhere, is perhaps nowhere more interesting and successful\nthan in what concerns the nucleus. Of the whole cell, the nucleus is to\nhim, as it was to Schleiden, Schwann, and others, the most important\nelement. And this is the view to which I, who have little business to\nspeak, wish success. This universe is not an accidental cavity, in which\nan accidental dust has been accidentally swept into heaps for the\naccidental evolution of the majestic spectacle of organic and inorganic\nlife. That majestic spectacle is a spectacle as plainly for the eye of\nreason as any diagram of the mathematician. That majestic spectacle\ncould have been constructed, was constructed, only in reason, for\nreason, and by reason. From beyond Orion and the Pleiades, across the\ngreen hem of earth, up to the imperial personality of man, all, the\nfurthest, the deadest, the dustiest, is for fusion in the invisible\npoint of the single Ego\u2014_which alone glorifies it_. _For_ the subject,\nand on the model of the subject, all is made. Therefore it is\nthat\u2014though, precisely as there are acephalous monsters by way of\nexception and deformity, there may be also at the very extremity of\nanimated existence cells without a nucleus\u2014I cannot help believing that\nthis nucleus itself, as analogue of the subject will yet be proved the\nmost important and indispensable of all the normal cell-elements. Even\nthe phenomena of the impregnated egg seem to me to support this view. In\nthe egg, on impregnation, it seems to me natural (I say it with a smile)\nthat the old sun that ruled it should go down, and that a new sun,\nstronger in the combination of the new and the old, should ascend into\nits place!\n\nBe these things as they may, we have now overwhelming evidence before us\nfor concluding, with reference to Mr. Huxley\u2019s first proposition,\nthat\u2014in view of the nature of microscopic science\u2014in view of the state\nof belief that obtains at present as regards nucleus, membrane, and\nentire cell\u2014even in view of the supporters of protoplasm itself\u2014Mr.\nHuxley is not authorized to speak of a physical matter of life; which,\nfor the rest, if granted, would, for innumerable and, as it appears to\nme, irrefragable reasons, be obliged to acknowledge for itself, not\nidentity, but an infinite diversity in power, in form and in substance.\n\nSo much for the first proposition in Mr. Huxley\u2019s essay, or that which\nconcerns protoplasm, as a supposed matter of life, identical itself, and\ninvolving the identity of all the various organs and organisms which it\nis assumed to compose. What now of the second proposition, or that which\nconcerns the materiality at once of protoplasm, and of all that is\nconceived to derive from protoplasm? In other words, though, so to\nspeak, for organic bricks anything like an organic clay still awaits the\nproof, I ask, if the bricks are not the same because the clay is not the\nsame, what if the materiality of the former is equally unsupported by\nthe materiality of the latter? Or what if the functions of protoplasm\nare not properties of its mere molecular constitution?\n\nFor this is Mr. Huxley\u2019s second proposition, namely, That all vital and\nintellectual functions are but the properties of the molecular\ndisposition and changes of the material basis (protoplasm) of which the\nvarious animals and vegetables consist. With the conclusions now before\nus, it is evident that to enter at all on this part of Mr. Huxley\u2019s\nargumentation is, so far as we are concerned, only a matter of grace. In\norder that it should have any weight, we must grant the fact, at once of\nthe existence of a matter of life, and of all organs and organisms being\nbut aggregates of it. This, obviously, we cannot now do. By way of\nhypothesis, however, we may assume it. Let it be granted, then, that\n_pro hac vice_ there _is_ a physical basis of life with all the\nconsequences named; and now let us see how Mr. Huxley proceeds to\nestablish its materiality.\n\nThe whole former part of Mr. Huxley\u2019s essay consists (as said) of fifty\nparagraphs, and the argument immediately concerned is confined to the\nlatter ten of them. This argument is the simple chemical analogy that,\nunder stimulus of an electric spark, hydrogen and oxygen uniting into an\nequivalent weight of water, and, under stimulus of pre\u00ebxisting\nprotoplasm, carbon, hydrogen, oxygen, and nitrogen uniting into an\nequivalent weight of protoplasm, there is the same warrant for\nattributing the properties of the consequent to the properties of the\nantecedents in the latter case as in the former. The properties of\nprotoplasm are, in origin and character, precisely on the same level as\nthe properties of water. The cases are perfectly parallel. It is as\nabsurd to attribute a new entity vitality to protoplasm, as a new entity\naquosity to water. Or, if it is by its mere chemical and physical\nstructure that water exhibits certain properties called aqueous, it is\nalso by its mere chemical and physical structure that protoplasm\nexhibits certain properties called vital. All that is necessary in\neither case is, \u201cunder certain conditions,\u201d to bring the chemical\nconstituents together. If water is a molecular complication, protoplasm\nis equally a molecular complication, and for the description of the one\nor the other there is no change of language required. A new substance\nwith new qualities results in precisely the same way here, as a new\nsubstance with new qualities there; and the derivative qualities are not\nmore different from the primitive qualities in the one instance, than\nthe derivative qualities are different from the primitive qualities in\nthe other. Lastly, the _modus operandi_ of pre\u00ebxistent protoplasm is not\nmore unintelligible than that of the electric spark. The conclusion is\nirresistible, then, that all protoplasm being reciprocally convertible,\nand consequently identical, the properties it displays, vitality and\nintellect included, are as much the result of molecular constitution as\nthose of water itself.\n\nIt is evident, then, that the fulcrum on which Mr. Huxley\u2019s second\nproposition rests, is a single inference from a chemical analogy.\nAnalogy, however, being never identity, is apt to betray. The difference\nit hides may be essential, that is, while the likeness it shows may be\ninessential\u2014so far as the conclusion is concerned. That this mischance\nhas overtaken Mr. Huxley here, it will, I fancy, not be difficult to\ndemonstrate.\n\nThe analogy to which Mr. Huxley trusts has two references: one, to\nchemical composition, and one to a certain stimulus that determines it.\nAs regards chemical composition, we are asked, by virtue of the analogy\nobtaining, to identify, as equally simple instances of it, protoplasm\nhere and water there; and, as regards the stimulus in question, we are\nasked to admit the action of the electric spark in the one case to be\nquite analogous to the action of pre\u00ebxisting protoplasm in the other. In\nboth references I shall endeavor to point out that the analogy fails;\nor, as we may say it also, that, even to Mr. Huxley, it can only seem to\nsucceed by discounting the elements of difference that still subsist.\n\nTo begin with chemical combination, it is not unjust to demand that the\nanalogy which must be admitted to exist in that, and a general physical\nrespect, should not be strained beyond its legitimate limits. Protoplasm\ncannot be denied to be a chemical substance; protoplasm cannot be denied\nto be a physical substance. As a compound of carbon, hydrogen, oxygen\nand nitrogen, it comports itself chemically\u2014at least in ultimate\ninstance\u2014in a manner not essentially different from that in which water,\nas a compound of hydrogen and oxygen, comports itself chemically. In\nmere physical aspect, again, it may count quality for quality with water\nin the same aspect. In short, so far as it is on chemical and physical\nstructure that the possession of distinctive properties in any case\ndepends, both bodies may be allowed to be pretty well on a par. The\nanalogy must be allowed to hold so far: so far but no farther. One step\nfarther and we see not only that protoplasm has, like water, a chemical\nand physical structure; but that, unlike water, it has also an organized\nor organic structure. Now this, on the part of protoplasm, is a\npossession in excess; and with relation to that excess there can be no\ngrounds for analogy. This, perhaps, is what Mr. Huxley has omitted to\nconsider. When insisting on attributing to protoplasm the qualities it\npossessed, because of its chemical and physical structure, if it was for\nchemical and physical structure that we attributed to water _its_\nqualities, he has simply forgotten the addition to protoplasm of a third\nstructure that can only be named organic. \u201cIf the phenomena exhibited by\nwater are its properties, so are those presented by protoplasm, living\nor dead, its properties.\u201d When Mr. Huxley speaks thus, Exactly so, we\nmay answer: \u201cliving or dead!\u201d That alternative is simply slipped in and\npassed; but it is in that alternative that the whole matter lies.\nChemically, dead protoplasm is to Mr. Huxley quite as good as living\nprotoplasm. As a sample of the article, he is quite content with dead\nprotoplasm, and even swallows it, he says, in the shape of bread,\nlobster, mutton, etc., with all the satisfactory results to be\ndesired.\u2014Still, as concerns the argument, it must be pointed out that it\nis only these that can be placed on the same level as water; and that\nliving protoplasm is not only unlike water, but it is unlike dead\nprotoplasm. Living protoplasm, namely, is identical with dead protoplasm\nonly so far as its chemistry is concerned (if even so much as that); and\nit is quite evident, consequently, that difference between the two\ncannot depend on that in which they are identical\u2014cannot depend on the\nchemistry. Life, then, is no affair of chemical and physical structure,\nand must find its explanation in something else. It is thus that, lifted\nhigh enough, the light of the analogy between water and protoplasm is\nseen to go out. Water, in fact, when formed from hydrogen and oxygen,\nis, in a certain way and in relation to them, no new product; it has\nstill, like them, only chemical and physical qualities; it is still, as\nthey are, inorganic. So far as _kind_ of power is concerned, they are\nstill on the same level. But not so protoplasm, where, with preservation\nof the chemical and physical likeness there is the addition of the\nunlikeness of life, of organization, and of ideas. But the addition is a\nnew world\u2014a new and higher world, the world of a self-realizing thought,\nthe world of an _entelechy_. The change of language objected to by Mr.\nHuxley is thus a matter of necessity, for it is _not_ mere molecular\ncomplication that we have any longer before us, and the qualities of the\nderivative are essentially and absolutely different from the qualities\nof the primitive. If we did invent the term aquosity, then, as an\nabstract sign for all the qualities of water, we should really do very\nlittle harm; but aquosity and vitality would still remain essentially\nunlike. While for the invention of aquosity there is little or no call,\nhowever, the fact in the other case is that we are not only compelled to\ninvent, but to _perceive_ vitality. We are quite willing to do as Mr.\nHuxley would have us to do: look on, watch the phenomena, and name the\nresults. But just in proportion to our faithfulness in these respects is\nthe necessity for the recognition of a new world and a new nomenclature.\nThere are certainly different states of water, as ice and steam; but the\nrelation of the solid to the liquid, or of either to the vapor, surely\noffers no analogy to the relation of protoplasm dead to protoplasm\nalive. That relation is not an analogy but an antithesis, the antithesis\nof antitheses. In it, in fact, we are in presence of the one\nincommunicable gulf\u2014the gulf of all gulfs\u2014that gulf which Mr. Huxley\u2019s\nprotoplasm is as powerless to efface as any other material expedient\nthat has ever been suggested since the eyes of men first looked into\nit\u2014the mighty gulf between death and life.\n\nThe differences alluded to (they are, in order, organization and life,\nthe objective idea\u2014design, and the subjective idea\u2014thought), it may be\nremarked, are admitted by those very Germans to whom protoplasm, name\nand thing, is due. They, the most advanced and innovating of them,\ndirectly avow that there is present in the cell \u201can architectonic\nprinciple that has not yet been detected.\u201d In pronouncing protoplasm\ncapable of active or vital movements, they do by that refer, they admit\nalso, to an immaterial force, and they ascribe the processes exhibited\nby protoplasm\u2014in so many words\u2014not to the molecules, but to organization\nand life. It is remarked by Kant that \u201cthe reason of the specific mode\nof existence of every part of a living body lies in the whole, whilst\nwith dead masses each part bears this reason within itself;\u201d and this\nindeed is how the two worlds are differentiated. A drop of water, once\nformed, is there passive for ever, susceptible to influence, but\nindifferent to influence, and what influence reaches it is wholly from\nwithout. It may be added to, it may be subtracted from; but infinitely\napathetic quantitatively, it is qualitatively independent. It is\nindifferent to its own physical parts. It is without contractility,\nwithout alimentation, without reproduction, without specific function.\nNot so the cell, in which the parts are dependent on the whole, and the\nwhole on the parts; which has its activity and _raison d\u2019\u00eatre_ within;\nwhich manifests all the powers which we have described water to want;\nand which requires for its continuance conditions of which water is\nindependent. It is only so far as organization and life are concerned,\nhowever, that the cell is thus different from water. Chemically and\nphysically, as said, it can show with it quality for quality. How\nstrangely Mr. Huxley\u2019s deliverances show beside these facts! He can \u201csee\nno break in the series of steps in molecular complication;\u201d but,\nglaringly obvious, there is a step added that is not molecular at all,\nand that has its supporting conditions completely elsewhere. The\nmolecules are as fully accounted for in protoplasm as in water; but the\nsum of qualities, thus exhausted in the latter, is not so exhausted in\nthe former, in which there are qualities due, plainly, not to the\nmolecules as molecules, but to the form into which they are thrown, and\nthe force that makes that form one. When the chemical elements are\nbrought together, Mr. Huxley says, protoplasm is formed, \u201cand this\nprotoplasm exhibits the phenomena of life;\u201d but he ought to have added\nthat these phenomena are themselves added to the phenomena for which all\nthat relates to chemistry stands, and are there, consequently, only by\nreason of some other determinant. New consequents necessarily demand new\nantecedents. \u201cWe think fit to call different kinds of matter carbon,\noxygen, hydrogen, and nitrogen, and to speak of the various powers and\nactivities of these substances as the properties of the matter of which\nthey are composed.\u201d That, doubtless, is true, we say; but such\nstatements do not exhaust the facts. We call water hydrogen and oxygen,\nand attribute _its_ properties to the properties of them. In a chemical\npoint of view, we ought to do the same thing for ice and steam; yet, for\nall the chemical identity, water is not ice, nor is either steam. Do we,\nthen, in these cases, make nothing of the _difference_, and in its\ndespite enjoy the satisfaction of viewing the three as one? Not so; we\nask a reason for the difference; we demand an antecedent that shall\nrender the consequent intelligible. The chemistry of oxygen and hydrogen\nis not enough in explanation of the threefold form; and by the very\nnecessity of the facts we are driven to the addition of heat. It is\nprecisely so with protoplasm in its twofold form. The chemistry\nremaining the same in each (if it really does so), we are compelled to\nseek elsewhere a reason for the difference of living from dead\nprotoplasm. As the differences of ice and steam from water lay not in\nthe hydrogen and oxygen, but in the heat, so the difference of living\nfrom dead protoplasm lies not in the carbon, the hydrogen, the oxygen,\nand the nitrogen, but in the vital organization. In all cases, for the\nnew quality, plainly, we must have a new explanation. The qualities of a\nsteam-engine are not the results of its simple chemistry. We do apply to\nprotoplasm the same conceptions, then, that are legitimate elsewhere,\nand in allocating properties and explaining phenomena we simply insist\non Mr. Huxley\u2019s own distinction of \u201cliving or dead.\u201d That, in fact, is\nto us the distinction of distinctions, and we admit no vital action\nwhatever, not even the dullest, to be the result of the _molecular_\naction of the protoplasm that displays it. The very protoplasm of the\nnettle-sting, with which Mr. Huxley begins, is already vitally\norganized, and in that organization as much superior to its own\nmolecules as the steam-engine, in its mechanism, to its own wood and\niron. It were indeed as rational to say that there is no principle\nconcerned in a steam-engine or a watch but that of its molecular forces,\nas to make this assertion of organized matter. Still there are degrees\nin organization, and the highest forms of life are widely different from\nthe lowest. Degrees similar we see even in the inorganic world. The\npersistent flow of a river is, to the mighty reason of the solar system,\nin some such proportion, perhaps, as the rhizopod to man. In protoplasm,\neven the lowest, then, but much more conspicuously in the highest, there\nis, in addition to the molecular force, another force unsignalized by\nMr. Huxley\u2014the force of vital organization.\n\nBut this force is a rational unity, and that is an idea; and this I\nwould point to as a second form of the addition to the chemistry and\nphysics of protoplasm. We have just seen, it is true, that an idea may\nbe found in inorganic matter, as in the solar and sidereal systems\ngenerally. But the idea in organized matter is not one operative, so to\nspeak, from without: it is one operative from within, and in an\ninfinitely more intimate and pervading manner. The units that form the\ncomplement of an inorganic system are but independently and externally\nin place, like units in a procession; but in what is organized there is\nno individual that is not sublated into the unity of the single life.\nThis is so even in protoplasm. Mr. Huxley, it is true, desiderates, as\nresult of mere ordinary chemical process, a life-stuff in mass, as it\nwere in the web, to which he has only to resort for cuttings and\ncuttings in order to produce, by aggregation, what organized individual\nhe pleases. But the facts are not so: we cannot have protoplasm in the\nweb, but the piece. There is as yet no _matter_ of life; there are still\n_cells_ of life. It is no shred of protoplasm\u2014no spoonful or\ntoothpickful\u2014that can be recognized as adequate to the function and the\nname. Such shred may wriggle a moment, but it produces nought, and it\ndies. In the smallest, lowest protoplasm-cell, then, we have this\nrational unity of a complement of individuals that only are for the\nwhole and exist in the whole. This is an idea, therefore; this is\ndesign: the organized concert of many to a single common purpose. The\nrudest savage that should, as in Paley\u2019s illustration, find a watch, and\nshould observe the various contrivances all controlled by the single end\nin view, would be obliged to acknowledge\u2014though in his own way\u2014that what\nhe had before him was no mere physical, no mere molecular product. So in\nprotoplasm: even from the first, but, quite undeniably, in the completed\norganization at last, which alone it was there to produce; for a single\nidea has been its one manifestation throughout. And in what machinery\ndoes it not at length issue? Was it molecular powers that invented a\nrespiration\u2014that perforated the posterior ear to give a balance of\nair\u2014that compensated the _fenestra ovalis_ by a _fenestra rotunda_\u2014that\nplaced in the auricular sacs those _otolithes_, those express stones for\nhearing? Such machinery! The _chord\u00e6 tendine\u00e6_ are to the valves of the\nheart exactly adjusted check-strings; and the contractile _column\u00e6\ncarne\u00e6_ are set in, under contraction and expansion, to equalize their\nlength to their office. Membranes, rods, and liquids\u2014it required the\nexpress experiment of man to make good the fact that the inventor of the\near had availed himself of the most perfect apparatus possible for his\npurpose. And are we to conceive such machinery, such apparatus, such\ncontrivances merely molecular? Are molecules adequate to such\nthings\u2014molecules in their blind passivity, and dead, dull insensibility?\nIs it to molecular agency Mr. Huxley himself owes that \u201csingular inward\nlaboratory\u201d of which he speaks, and without which all the protoplasm in\nthe world would be useless to him? Surely, in the presence of these\nmanifest ideas, it is impossible to attribute the single peculiar\nfeature of protoplasm\u2014its vitality, namely\u2014to mere molecular chemistry.\nProtoplasm, it is true, breaks up into carbon, hydrogen, oxygen, and\nnitrogen, as water does into hydrogen and oxygen; but the watch breaks\nsimilarly up into mere brass, and steel, and glass. The loose materials\nof the watch\u2014even its chemical material if you will\u2014replace its weight,\nquite as accurately as the constituents carbon, etc., replace the weight\nof the protoplasm. But neither these nor those replace the vanished\nidea, which was alone the important element. Mr. Huxley saw no break in\nthe series of steps in molecular complication; but, though not\nmolecular, it is difficult to understand what more striding, what more\nabsolute break could be desired than the break into an idea. It is of\nthat break alone that we think in the watch; and it is of that break\nalone that we should think in the protoplasm which, far more cunningly,\nfar more rationally, constructs a heart, an eye or an ear. That is the\nbreak of breaks, and explain it as we may, we shall never explain it by\nmolecules.\n\nBut, if inorganic elements as such are inadequate to account either for\nvital organization or the objective idea of design, much more are they\ninadequate, in the third place, to account for the subjective idea, for\nthe phenomena of thought as thought. Yet Mr. Huxley tells us that\nthought is but the expression of the molecular changes of protoplasm.\nThis he only tells us; this he does not prove. He merely says that, if\nwe admit the functions of the lowest forms of life to be but \u201cdirect\nresults of the nature of the matter of which they are composed,\u201d we must\nadmit as much for the functions of the highest. We have not admitted Mr.\nHuxley\u2019s presupposition; but, even with its admission, we should not\nfeel bound to admit his conclusion. In such a mighty system of\ndifferences, there are ample room and verge enough for the introduction\nof new motives. We can say here at once, in fact, that as thought, let\nits connection be what it may with, has never been proved to result\nfrom, organization, no improvement of the proof required will be found\nin protoplasm. No one power that Mr. Huxley signalizes in protoplasm can\naccount for thought: not alimentation, and not reproduction, certainly;\nbut not even contractility. We have seen already that there is no proof\nof contraction being necessary even for the simplest sensation; but much\nless is there any proof of a necessity of contraction for the inner and\nindependent operations of the mind. Mr. Huxley himself admits this. He\nsays: \u201cSpeech, gesture, and every other form of human action are, in the\nlong-run, resolvable into muscular contraction;\u201d and so, \u201ceven those\nmanifestations of intellect, of feeling, and of will, which we rightly\nname the higher faculties, are not excluded from this classification,\ninasmuch as to every one _but the subject of them_, they are known only\nas transitory changes in the relative positions of parts of the body.\u201d\nThe concession is made here, we see that these manifestations are\ndifferently known to the subject of them. But we may first object that,\nif even that privileged \u201cevery one but the subject\u201d were limited to a\nknowledge of contractions, he would not know much. It is only because he\nknows, first of all, a thinker and willer of contractions that these\nthemselves cease to be but passing externalities, and transitory\ncontingencies. Neither is it reasonable to assert an identity of nature\nfor contractions, and for that which they only represent. It would\nhardly be fair to confound either the receiver or the sender of a\ntelegraphic message, with the movements which alone bore it, and without\nwhich it would have been impossible. The sign is not the thing\nsignified, it is but the servant of the signifier\u2014his own arbitrary\nmark\u2014and intelligible, in the first place, only to him. It is the\nmeaning, in all cases, that is alone vital; the sign is but an accident.\nTo convert the internality into the arbitrary externality that simply\nexpresses it, is for Mr. Huxley only an oversight. Your ideas are made\nknown to your neighbors by contractions, therefore your ideas are of the\nsame nature as contractions! Or, even to take it from the other side,\nyour neighbor perceives in you contractions only, and therefore your\nideas are contractions! Are not the vital elements here present the two\ncorrespondent internalities, between which the contractions constitute\nbut an arbitrary chain of external communication, that is so now, but\nmay be otherwise again? The ringing of the bell at the window is not\nprecisely the dwarf within. Nor are Engineer Chappe\u2019s \u201cwooden arms and\nelbow-joints jerking and fugling in the air,\u201d to be identified with\nEngineer Chappe himself. For the higher faculties, even for speech,\netc., assuredly Mr. Huxley might have well spared himself this\nsuperfluous and inapplicable reference to contraction.\n\nBut, in the middle of it, as we have seen, Mr. Huxley concedes that\nthese manifestations are differently known to the subject of them. If\nso, what becomes of his assertion of but a certain number of powers for\nprotoplasm? The manifestations of the higher faculties are not known to\nthe subject of them by contraction, etc. By what, then, are they known?\nAccording to Mr. Huxley, they can only be known by the powers of\nprotoplasm; and therefore, by his own showing, protoplasm must possess\npowers other than those of his own assertion. Mr. Huxley\u2019s one great\npower of contractility, Mr. Huxley himself confesses to be inapplicable\nhere. Indeed, in his Physiology (p. 193), he makes such an avowal as\nthis: \u201cWe class _sensations_, along with _emotions_, and _volitions_,\nand _thoughts_, under the common head of states of _consciousness_; but\nwhat consciousness is we know not, and how it is that anything so\nremarkable as a state of consciousness comes about as the result of\nirritating nervous tissue, is just as unaccountable as the appearance of\nthe Djin when Aladdin rubbed his lamp in the story.\u201d Consciousness\nplainly was not muscular contraction to Mr. Huxley when he wrote his\nPhysiology; it is only since then that he has gone over to the assertion\nof no power in protoplasm but the triple power, contractility, etc. But\nthe truth is only as his Physiology has it\u2014the cleft is simply, as Mr.\nHuxley acknowledges it there, absolute. On one side, there is the world\nof externality, where all is body by body, and away from one another\u2014the\nboundless reciprocal exclusion of the infinite object. On the other\nside, there is the world of internality, where all is soul to soul, and\naway into one another\u2014the boundless reciprocal inclusion of the infinite\nsubject. This\u2014even while it is true that, for subject to be subject, and\nobject, object, the boundless intussuscepted multiplicity of the single\ninvisible point of the one is but the dimensionless casket into which\nthe illimitable Genius of the other must retract and withdraw itself\u2014is\nthe difference of differences; and certainly it is not internality that\ncan be abolished before externality. The proof for the absoluteness of\nthought, the subject, the mind, is, on its side, pretty well perfect. It\nis not necessary here, however, to enter into that proof at length.\nBefore passing on, I may simply point to the fact that, if thought is to\nbe called a function of matter, it must be acknowledged to be a function\nwholly peculiar and unlike any other. In all other functions, we are\npresent to processes which are in the same sense physical as the organs\nthemselves. So it is with lung, stomach, liver, kidney, where every step\ncan be followed, so to speak, with eye and hand; but all is changed when\nwe have to do with mind as the function of brain. Then, indeed, as Mr.\nHuxley thought in his Physiology, we are admitted, as if by touch of\nAladdin\u2019s lamp, to a world absolutely different and essentially new\u2014to a\nworld, on its side of the incommunicable cleft, as complete, entire,\nindependent, self-contained, and absolutely _sui generis_, as the world\nof matter on the other side. It will be sufficient here to allude to as\nmuch as this, with special reference to the fact that, so far as this\nargument is concerned, protoplasm has not introduced any the very\nslightest difference. All the ancient reasons for the independence of\nthought as against organization, can be used with even more striking\neffect as against protoplasm; but it will be sufficient to indicate\nthis, so much are the arguments in question a common property now.\nThought, in fact, brings with it its own warrant; or it brings with it,\nto use the phrase of Burns, \u201cits patent of nobility direct from Almighty\nGod.\u201d And that is the strongest argument on this whole side. Throughout\nthe entire universe, organic and inorganic, thought is the controlling\nsovereign; nor does matter anywhere refuse its allegiance. So it is in\nthought, too, that man has _his_ patent of nobility, believes that he is\ncreated in the image of God, and knows himself a free-man of infinitude.\n\nBut the analogy, in the hands of Mr. Huxley, has, we have seen, a second\nreference\u2014that, namely, to the excitants, if we may call them so, which\n_determine_ combination. The _modus operandi_, Mr. Huxley tells us, of\npre\u00ebxisting protoplasm in determining the formation of new protoplasm,\nis not more unintelligible than the _modus operandi_ of the electric\nspark in determining the formation of water; and so both, we are left to\ninfer, are perfectly analogous. The inferential turn here is rather a\nfavorite with Mr. Huxley. \u201cBut objectors of this class,\u201d he says on an\nearlier occasion, in allusion to those who hesitate to conclude from\ndead to living matter, \u201cdo not seem to reflect that it is also, in\nstrictness, true that we know nothing about the composition of any body\nwhatever as it is.\u201d In the same neighborhood, too, he argues that,\nthough impotent to restore to decomposed calc-spar its original form, we\ndo not hesitate to accept the chemical analysis assigned to it, and\nshould not, consequently, any more hesitate because of any mere\ndifference of form to accept the analysis of dead for that of living\nprotoplasm. It is certainly fair to point out that, if we bear ignorance\nand impotence with equanimity in one case, we may equally so bear them\nin another; but it is not fair to convert ignorance into knowledge, nor\nimpotence into power. Yet it is usual to take such statements loosely,\nand let them pass. It is not considered that, if we know nothing about\nthe composition of any body whatever as it is, then we do know nothing,\nand that it is strangely idle to offer absolute ignorance as a support\nfor the most dogmatic knowledge. If such statements are, as is really\nexpected for them, to be accepted, yet not accepted, they are the\nstultification of all logic. Is the chemistry of living to be seen to be\nthe same as the chemistry of dead protoplasm, because we know nothing\nabout the composition of any body whatever as it is? We know perfectly\nwell that black is white, for we are absolutely ignorant of either as it\nis! The _form_ of the calc-spar, which (the spar) we _can_ analyze, we\ncannot restore; therefore the _form_ of the protoplasm, which we\n_cannot_ analyze, has nothing to do with the matter in hand; and the\nchemistry of what is dead may be accepted as the chemistry of what is\nliving! In the case of reasoning so irrelevant it is hardly worth while\nreferring to what concerns the forms themselves; that they are totally\nincommensurable, that in all forms of calc-spar there is no question but\nof what is physical, while in protoplasm the change of form is\nintroduction into an entire new world. As in these illustrations, so in\nthe case immediately before us. No appeal to ignorance in regard to\nsomething else, the electric spark, should be allowed to transform\nanother ignorance, that of the action of pre\u00ebxisting protoplasm, into\nknowledge, here into _the_ knowledge that the two unknown things,\nbecause of non-knowledge, are\u2014perfectly analogous! That this analogy\ndoes not exist\u2014that the electric spark and pre\u00ebxisting protoplasm are,\nin their relative places, _not_ on the same chemical level\u2014this is the\nmain point for us to see; and Mr. Huxley\u2019s allusion to our ignorance\nmust not be allowed to blind us to it. Here we have in a glass vessel so\nmuch hydrogen and oxygen, into which we discharge an electric spark, and\nwater is the result. Now what analogy is it possible to perceive between\nthis production of water by external experiment and the production of\nprotoplasm by protoplasm? The discrepancy is so palpable that it were\nimpertinent to enlarge on it. The truth is just this, that the measured\nand mixed gases, the vessel, and the spark, in the one case, are as\nunlike the fortuitous food, the living organs, and the long process of\nassimilation in the other case, as the product water is unlike the\nproduct protoplasm. No; that the action of the electric spark should be\nunknown, is no reason why we should not insist on protoplasm for\nprotoplasm, on life for life. Protoplasm can only be produced by\nprotoplasm, and each of all the innumerable varieties of protoplasm,\nonly by its own kind. For the protoplasm of the worm we must go to the\nworm, and for that of the toad-stool to the toad-stool. In fact, if all\nliving beings come from protoplasm, it is quite as certain that, but for\nliving beings, protoplasm would disappear. Without an egg you cannot\nhave a hen\u2014that is true; but it is equally true that, without a hen, you\ncannot have an egg. So in protoplasm; which, consequently, in the\nproduction of itself, offers no analogy to the production, or\nprecipitation by the electric spark, not of itself, but of water.\nBesides, if for protoplasm, pre\u00ebxisting protoplasm, is always necessary,\nhow was there ever a first protoplasm?\n\nGenerally, then, Mr. Huxley\u2019s analogy does not hold, whether in the one\nreference or the other, and Mr. Huxley has no warrant for the reduction\nof protoplasm to the mere chemical level which he assigns it in either.\nThat level is brought very prominently forward in such expressions as\nthese: That it is only necessary to bring the chemical elements\n\u201ctogether,\u201d \u201cunder certain conditions,\u201d to give rise to the more complex\nbody, protoplasm, just as there is a similar expedient to give rise to\nwater; and that, under the influence of pre\u00ebxisting living protoplasm,\ncarbonic acid, water, and ammonia disappear, and an equivalent weight of\nprotoplasm makes its appearance, just as, under the influence of the\nelectric spark, hydrogen and oxygen disappear, and an equivalent weight\nof water makes its appearance. All this, plainly, is to assume for\nprotoplasm such mere chemical place and nature as consist not with the\nfacts. The cases are, in truth, not parallel, and the \u201ccertain\nconditions\u201d are wholly diverse. All that is said we can do at will for\nwater, but nothing of what is said can we do at will for protoplasm. To\nsay we can feed protoplasm, and so make protoplasm at will produce\nprotoplasm, is very much, in the circumstances, only to say, and is not\nto say, that, in this way, we make a chemical experiment. To insist on a\nchemical analogy, in fact, between water and protoplasm, is to omit the\ndifferences not covered by the analogy at all\u2014thought, design, life, and\nall the processes of organization; and it is but simple procedure to\nomit these differences only by an appeal to ignorance elsewhere.\n\nIt is hardly worth while, perhaps, to refer now again to the\ndifference\u2014here, however, once more incidentally suggested\u2014between\nprotoplasm and protoplasm. Mr. Huxley, that is, almost in his very last\nword on this part of the argument, seems to become aware of the bearing\nof this on what relates to materiality, and he would again stamp\nprotoplasm (and with it life and intellect), into an indifferent\nidentity. In order that there should be no break between the lowest\nfunctions and the highest (the functions of the fungus and the functions\nof man), he has \u201cendeavored to prove,\u201d he says, that the protoplasm of\nthe lowest organisms is \u201cessentially identical with, and most readily\nconverted into that of any animal.\u201d On this alleged reciprocal\n_convertibility_ of protoplasm, then, Mr. Huxley would again found as\nwell an inference of identity, as the further conclusion that the\nfunctions of the highest, not less than those of the lowest animals, are\nbut the molecular manifestations of their common protoplasm.\n\nPlainly here it is only the consideration, not of function, but of the\nalleged reciprocal _convertibility_ that is left us now. Is this true,\nthen? Is it true that every organism can digest every other organism,\nand that thus a relation of identity is established between that which\ndigests and whatever is digested? These questions place Mr. Huxley\u2019s\ngeneral enterprise, perhaps, in the most glaring light yet; for it is\nvery evident that there is an end of the argument if all foods and all\nfeeders are essentially identical both with themselves and with each\nother. The facts of the case, however, I believe to be too well known to\nrequire a single word here on my part. It is not long since Mr. Huxley\nhimself pointed out the great difference between the foods of plants and\nthe foods of animals; and the reader may be safely left to think for\nhimself of _ruminantia_ and _carnivora_, of soft bills and hard bills,\nof molluscs and men. Mr. Huxley talks feelingly of the possibility of\nhimself feeding the lobster quite as much as of the lobster feeding him;\nbut such pathos is not always applicable; it is not likely that a sponge\nwould be to the stomach of Mr. Huxley any more than Mr. Huxley to the\nstomach of a sponge.\n\nBut a more important point is this, that the functions themselves remain\nquite apart from the alleged convertibility. We can neither acquire the\nfunctions of what we eat, nor impart our functions to what eats us. We\nshall not come to fly by feeding on vultures, nor they to speak by\nfeeding on us. No possible manure of human brains will enable a\ncorn-field to reason. But if functions are inconvertible, the\nconvertibility of the protoplasm is idle. In this inconvertibility,\nindeed, functions will be seen to be independent of mere chemical\ncomposition. And that is the truth: for functions there is more required\nthan either chemistry or physics.\n\nIt is to be acknowledged\u2014to notice one other incidental suggestion, for\nthe sake of completeness, and by way of transition to the final\nconsideration of possible objections\u2014that Mr. Huxley would be very much\nassisted in his identification of differences, were but the theories of\nthe molecularists, on the one hand, and of Mr. Darwin, on the other,\nonce for all established. The three modes of theorizing indicated,\nindeed, are not without a tendency to approach one another; and it is\nprecisely their union that would secure a definitive triumph for the\ndoctrine of materialism. Mr. Huxley, as we have seen\u2014though what he\ndesiderates is an auto-plastic living _matter_ that, produced by\nordinary chemical processes, is yet capable of continuing and developing\nitself into new and higher forms\u2014still begins with the egg. Now the\ntheory of the molecularists would, for its part, remove all the\ndifficulties that, for materialism, are involved in this beginning; it\nwould place protoplasm undeniably at length on a merely chemical level;\nand would fairly enable Mr. Darwin, supplemented by such a life-stuff,\nto account by natural means for everything like an idea or thought that\nappears in creation. The misfortune is, however, that we must believe\nthe theory of the molecularists still to await the proof; while the\ntheory of Mr. Darwin has many difficulties peculiar to itself. This\ntheory, philosophically, or in ultimate analysis, is an attempt to prove\nthat design, or the objective idea, especially in the organic world, is\ndeveloped _in time_ by natural means. The time which Mr. Darwin demands,\nit is true, is an infinite time; and he thus gains the advantage of his\nprocesses being allowed greater _clearness_ for the understanding, in\nconsequence of the _obscurity_ of the infinite past in which they are\nplaced, and of which it is difficult in the first instance to deny any\npossibility whatever. Still it remains to be asked, Are such processes\ncredible in any time? What Mr. Darwin has done in aid of his view is,\nfirst, to lay before us a knowledge of facts in natural history of\nsurprising richness; and, second, to support this knowledge by an\ninexhaustible ingenuity of hypothesis in arrangement of appearances.\nNow, in both respects, whether for information or even interest, the\nvalue of Mr. Darwin\u2019s contribution will probably always remain\nindependent of the argument or arguments that might destroy his leading\nproposition; and it is with this proposition that we have here alone to\ndo. As said, we ask only, Is it true that the objective idea, the design\nwhich we see in the organized world, is the result in infinite time of\nthe necessary adaption of living structures to the peculiarities of the\nconditions by which they are surrounded?\n\nAgainst this theory, then, its own absolute generalization may be viewed\nas our first objection. In ultimate abstraction, that is, the only\nagency postulated by Mr. Darwin is time\u2014infinite time; and as regards\nactually existent beings and actually existent conditions, it is hardly\npossible to deny any possibility whatever to infinitude. If told, for\nexample, that the elephant, if only obliged _infinitely_ to run, might\nbe converted into the stag, how should we be able to deny? So also, if\nthe lengthening of the giraffe\u2019s neck were hypothetically attributed to\na succession of dearths in infinite time that only left the leaves of\ntrees for long-necked animals to live on, we should be similarly\nsituated as regards denial. Still it can be pointed out that ingenuity\nof natural conjecture has, in such cases, no less wide a field for the\nnegation than for the affirmation; and that, on the question of fact,\nnothing is capable of being determined. But we can also say more than\nthat\u2014we can say that any fruitful application even of _infinite time_ to\nthe _general problem of difference_ in the world is inconceivable. To\nexplain all from an absolute beginning requires us to commence with\nnothing; but to this nothing time itself is an addition. Time is an\nentity, a something, a difference added to the original identity: whence\nor how came time? Time cannot account for its own self; how is it that\nthere is such a thing as time? Then no conceivable brooding even of\ninfinite time could hatch the infinitude of space. How is it there is\nsuch a thing as space? No possible clasps of time and space, further,\ncould ever conceivably thicken into matter. How is it there is such a\nthing as matter? Lastly, so far, no conceivable brooding, or even\ngyrating, of a single matter in time and space could account for the\nspecification of matter\u2014carbon, gold, iodine, etc.\u2014as we see and know\nit. Time, space, matter, and the whole inorganic world, thus remain\nimpassive to the action even of infinite time; all _these_ differences\nremain incapable of being accounted for so.\n\nBut suppose no curiosity had ever been felt in this reference, which,\nthough scientifically indefensible, is quite possible, how about the\ntransition of the inorganic into the organic? Mr. Huxley tells us that,\nfor food, the plant needs nothing but its bath of smelling-salts.\nSuppose this bath now\u2014a pool of a solution of carbonate of ammonia; can\nany action of sun, or air, or electricity, be conceived to develop a\ncell\u2014or even so much lump-protoplasm\u2014in this solution? The production of\nan initial cell in any such manner will not allow itself to be realized\nto thought. Then we have just to think for a moment of the vast\ndifferences into which, for the production of the present organized\nworld, this cell must be distributed, to shake our heads and say we\ncannot well refuse anything to an infinite time, but still we must\npronounce a problem of this reach hopeless.\n\nIt is precisely in conditions, however, that Mr. Darwin claims a\nsolution of this problem. Conditions concern all that relates to air,\nheat, light, land, water, and whatever they imply. Our second objection,\nconsequently, is, that conditions are quite inadequate to account for\npresent organized differences, from a single cell. Geological time, for\nexample, falls short, after all, of infinite time; or, in known\ngeological eras, let us calculate them as liberally as we may, there is\nnot time enough to account for the presently-existing varieties, from\none, or even several, primordial forms. So to speak, it is not _in_\ngeological time to account for the transformation of the elephant into\nthe stag from acceleration, or for that of the stag into the elephant\nfrom retardation, of movement. And we may speak similarly of the growth\nof the neck of the giraffe, or even of the elevation of the monkey into\nman. Moreover, time apart, conditions have no such power in themselves.\nIt is impossible to conceive of animal or vegetable effluvia ever\ncreating the nerve by which they are felt, and so gradually the\nSchneiderian membrane, nose, and whole olfactory apparatus. Yet these\neffluvia are the conditions of smell, and, _ex hypothesi_, ought to have\ncreated it. Did light, or did the pulsations of the air, ever by any\nlength of time, indent into the sensitive cell, eyes, and a pair of\neyes\u2014ears, and a pair of ears? Light conceivably might shine for ever\nwithout such a wonderfully complicated result as an eye. Similarly, for\ndelicacy and marvellous ingenuity of structure, the ear is scarcely\ninferior to the eye; and surely it is possible to think of a whole\ninfinitude of those fitful and fortuitous air-tremblings, which we call\nsound, without indentation into anything whatever of such an organ.\n\nA third objection to Mr. Darwin\u2019s theory is, that the play of natural\ncontingency in regard to the vicissitudes of conditions, has no title to\nbe named _selection_. Naturalists have long known and spoken of the\n\u201cinfluence of accidental causes;\u201d but Mr. Darwin was the first to apply\nthe term _selection_ to the action of these, and thus convert accident\ninto design. The agency to which Mr. Darwin attributes all the changes\nwhich he would signalize in animals is really the fortuitous contingency\nof brute nature; and it is altogether fallacious to call such process,\nor such non-process, by a term involving foresight and a purpose. We\nhave here, indeed, only a metaphor wholly misapplied. The German writer\nwho, many years ago, said \u201ceven the _genera_ are wholly a prey to the\nchanges of the external universal life,\u201d saw precisely what Mr. Darwin\nsees, but it never struck him to style contingency selection. Yet, how\ndangerous, how infectious, has not this ungrounded metaphor proved! It\nhas become a _principle_, a _law_, and been transferred by very genuine\nmen into their own sciences of philology and what not. People will\nwonder at all this by-and-by. But to point out the inapplicability of\nsuch a word to the processes of nature referred to by Mr. Darwin, is to\npoint out also the impossibility of any such contingencies proceeding,\nby graduated rise, from stage to stage, into the great symmetrical\norganic system\u2014the vast plan\u2014the grand harmonious whole\u2014by which we are\nsurrounded. This rise, this system, is really the objective idea; but it\nis utterly incapable of being accounted for by any such agency as\nnatural contingency in geological, or infinite, or any time. But it is\nthis which the word selection tends to conceal.\n\nWe may say, lastly, in objection, here, that, in the fact of \u201creversion\u201d\nor \u201catavism,\u201d Mr. Darwin acknowledges his own failure. We thus see that\nthe species as species is something independent, and holds its own\n_insita vis natur\u00e6_ within itself.\n\nProbably it is not his theory, then, that gives value to Mr. Darwin\u2019s\nbook; nor even his ready ingenuity, whatever interest it may lend: it is\nthe material information it contains. The ingenuity, namely, verges\nsomewhat on that Humian expedient of natural conjecture so copiously\nexemplified, on occasion of a few trite texts, in Mr. Buckle. But that\nnatural conjecture is always insecure, equivocal, and many-sided. It may\nbe said that ancient warfare, for example, giving victory always to the\npersonally ablest and bravest, must have resulted in the improvement of\nthe race; or that, the weakest being always necessarily left at home,\nthe improvement was balanced by deterioration; or that the ablest were\nnecessarily the most exposed to danger, and so, etc., etc., according,\nto ingenuity _usque ad infinitum_. Trustworthy conclusion is not\npossible to this method, but only to the induction of facts, or to\nscientific demonstration.\n\nNeither molecularists nor Darwinians, then, are able to level out the\ndifference between organic and inorganic, or between genera and genera\nor species and species. The differences persist despite of both; the\ndistributed identity remains unaccounted for. Nor, consequently, is Mr.\nDarwin\u2019s theory competent to explain the objective idea by any reference\nto time and conditions. Living beings do exist in a mighty chain from\nthe moss to the man; but that chain, far from founding, is founded in\nthe idea, and is not the result of any mere natural _growth_ of this\ninto that. That chain is itself the most brilliant stamp, the\nsign-manual, of design. On every ledge of nature, from the lowest to the\nhighest, there is a life that is _its_,\u2014a creature to represent it,\nreflect it\u2014so to speak, pasture on it. The last, highest, brightest link\nof this chain is man; the incarnation of thought itself, which is the\nsummation of this universe; man, that includes in himself all other\nlinks and their single secret\u2014the personified universe, the subject of\nthe world. Mr. Huxley makes but small reference to thought; he only\ntucks it in, as it were, as a mere appendicle of course.\n\nIt may be objected, indeed\u2014to reach the last stage in this\ndiscussion\u2014that, if Mr. Huxley has not disproved the conception of\nthought and life \u201cas a something which works through matter, but is\nindependent of it,\u201d neither have we proved it. But it is easy for us to\nreply that, if \u201c_independent of_\u201d means here \u201c_unconnected with_,\u201d we\nhave had no such object. We have had no object whatever, in fact, but to\nresist, now the extravagant assertion that all organized tissue, from\nthe lichen to Leibnitz, is alike in faculty, and again the equally\nextravagant assertion that life and thought are but ordinary products of\nmolecular chemistry. As regards the latter assertion, we have endeavored\nto show that the processes of vital organization (as self-production,\netc.) belong to another sphere, higher than, and very different from,\nthose of mechanical juxtaposition or chemical neutralization; that life,\nthen, is no mere product of matter as matter; that if no life can be\npointed to independent of matter, neither is there any life-stuff\nindependent of life; and that life, consequently, adds a new and higher\nforce to chemistry, as chemistry a new and higher force to mechanics,\netc. As for thought, the endeavor was to show that it was as independent\non the one side as matter on the other, that it controlled, used,\nsummed, and was the reason of matter. Thought, then, is not to be\nreached by any bridge from matter, that is a hybrid of both, and\nexplains the connection. The relation of matter to mind is not to be\nexplained as a transition, but as a _contrecoup_. In this relation,\nhowever, it is not the material, but the mental side, which the whole\nuniverse declares to be the dominant one.\n\nAs regards any objection to the arguments which we have brought against\nthe identity of protoplasm, again, these will lie in the phrase,\nprobably, \u201cdifference not of kind, but degree,\u201d or in the word\n\u201cmodification.\u201d The \u201cphrase\u201d may be now passed, for generic or specific\ndifference must be allowed in protoplasm, if not for the overwhelming\nreason that an infinitude of various kinds exist in it, each of which is\nself-productive and uninterchangeable with the rest, then for Mr.\nHuxley\u2019s own reason, that plants assimilate inorganic matter and animals\nonly organic. As for the objection \u201cmodification,\u201d again, the same\nconsideration of generic difference must prove fatal to it. This were\notherwise, indeed, could but the molecularists and Mr. Darwin succeed in\ndestroying generic difference; but in this, as we have seen, they have\nfailed. And this will be always so: who dogs identity, difference dogs\nhim. It is quite a justifiable endeavor, for example, to point out the\nidentity that obtains between veins and arteries on the one hand, as\nbetween these and capillaries on the other; but all the time the\ndifference is behind us; and when we turn to look, we see, for\ncirculation, the valves of the veins and the elastic coats of the\narteries as opposed to one another, and, for irrigation, the permeable\nwalls of the capillaries as opposed to both.\n\nGeneric differences exist then, and we cannot allow the word\n\u201cmodification\u201d to efface them in the interest of the identity claimed\nfor protoplasm. Brain-protoplasm is not bone-protoplasm, nor the\nprotoplasm of the fungus the protoplasm of man. Similarly, it is very\nquestionable how far the word \u201cmodification\u201d will warrant us in\nregarding with Mr. Huxley the \u201cducts, fibres, pollen, and ovules\u201d of the\nnettle as identical with the protoplasm of its sting. Things that\noriginate alike may surely eventuate in others which, chemically and\nvitally, far from being mere modifications, must be pronounced totally\ndifferent. Such eventuation must be held competent to what can only be\nnamed generic or specific difference. The \u201cchild\u201d is only \u201c_father_ of\nthe man\u201d\u2014it is not the man; who, moreover, in the course of an ordinary\nlife, we are told, has totally changed himself, not once, but many\ntimes, retaining at the last not one single particle of matter with\nwhich he set out. Such eventuations, whether called modifications or\nnot, certainly involve essential difference. And so situated are the\n\u201cducts, fibres, pollen, and ovules\u201d of the nettle, which, whether\ncompared with the protoplasm of the nettle-sting, or with that in which\nthey originated, must be held to here assumed, by their own actions,\nindisputable differences, physical, chemical, and vital, or in form,\nsubstance, and faculty.\n\nMuch, in fact, depends on definition here; and, in reference to\nmodification, it may be regarded as arbitrary when identity shall be\nadmitted to cease and difference to begin. There are the old Greek\npuzzles of the Bald Head and the Heap, for example. How many grains, or\nhow many hairs, may we remove before a heap of wheat is no heap, or a\nhead of hair bald? These concern quantity alone; but, in other cases,\nbone, muscle, brain, fungus, tree, man, there is not only a\nquantitative, but a qualitative difference; and in regard to such\ndifferences, the word modification can be regarded as but a cloak, under\nwhich identity is to be shuffled into difference, but remain identity\nall the same. The brick is but modified clay, Mr. Huxley intimates, bake\nit and paint it as you may; but is the difference introduced by the\nbaking and painting to be ignored? Is what Mr. Huxley calls the\n\u201cartifice\u201d not to be taken into account, leave alone the \u201cpotter?\u201d The\nstrong firm rope is about as exact an example of modification\nproper\u2014modification of the weak loose hemp\u2014as can well be found; but are\nwe to exclude from our consideration the whole element of difference due\nto the hand and brain of man? Not far from Burn\u2019s Monument, on the\nCalton Hill of Edinburgh, there lies a mass of stones which is\npotentially a church, the former Trinity College Church. Were this\nchurch again realized, would it be fair to call it a mere modification\nof the previous stones? Look now to the egg and the full-feathered fowl.\nChaucer describes to us the cock, \u201chight chaunteclere,\u201d that was to his\n\u201cfaire Pertelotte\u201d so dear:\u2014\n\n            \u201cHis comb was redder than the fine corall,\n             Embattled, as it were a castle-wall;\n             His bill was black, and as the jet it shone;\n             Like azure were his legges and his tone (toes);\n             His nailes whiter than the lilie flour,\n             And like the burned gold was his color.\u201d\n\nWould it be even as fair to call this fine fellow\u2014comb, wattles, spurs,\nand all\u2014a modified yolk, as to call the church but modified stones? If,\nin the latter case, an element of difference, altogether undeniable,\nseems to have intervened, is not such intervention at least quite as\nwell marked in the former? It requires but a slight analysis to detect\nthat all the stones in question are marked and numbered; but will any\nanalysis point out within the shell the various parts that only need\narrangement to become the fowl? Are the men that may take the stones,\nand, in a re-erected Trinity College Church, realize anew the idea of\nits architect, in any respect more wonderful than the unknown disposers\nof the materials of the fowl? That what realizes the idea should, in the\none case, be from without, and, in the other, from within, is no reason\nfor seeing more modification and less wonder in the latter than the\nformer. There is certainly no more reason for seeing the fowl in the\negg, and as identical with the egg, than for seeing a re-built Trinity\nCollege Church as identical with its unarranged materials. A part cannot\nbe taken for the whole, whether in space _or in time_. Mr. Huxley misses\nthis. He is so absorbed in the identity out of which, that he will not\nsee the difference into which, progress is made. As the idea of the\nchurch has the stones, so the idea of the fowl has the egg, for its\ncommencement. But to this idea, and in both cases, the terminal\nadditions belong, quite as much as the initial materials. If the idea,\nthen, add sulphur, phosphorus, iron, and what not, it must be credited\nwith these not less than with the carbon, hydrogen, etc., with which it\nbegan. It is not fair to mutter modification, as if it were a charm to\ndestroy all the industry of time. The protoplasm of the egg of the fowl\nis no more the fowl than the stones the church; and to identify, by\njuggle of a mere word, parts in time and wholes in time so different, is\nbut self-deception. Nay, in protoplasm, as we have so often seen,\ndifference is as much present at first as at last. Even in its germ,\neven in its initial identity, to call it so, protoplasm is already\ndifferent, for it issues in differences infinite.\n\nOmission of the consideration of difference, it is to be acknowledged,\nis not now-a-days restricted to Mr. Huxley. In the wonder that is\nusually expressed, for example, at Oken\u2019s _identification_ of the skull\nwith so many vertebr\u00e6, it is forgot that there is still implicated the\nwonder which we ought to feel at the unknown power that could, in the\nend, so _differentiate_ them. If the cornea of the eye and the enamel of\nthe teeth are alike but modified protoplasm, we must be pardoned for\nthinking more of the adjective than of the substantive. Our wonder is\nhow, for one idea, protoplasm could become one thing here, and, for\nanother idea, another so different thing there. We are more curious\nabout the modification than the protoplasm. In the difference, rather\nthan in the identity, it is, indeed, that the wonder lies. Here are\nseveral thousand pieces of protoplasm; analysis can detect no difference\nin them. They are to us, let us say, as they are to Mr. Huxley,\nidentical in power, in form, and in substance; and yet on all these\nseveral thousand little bits of apparently indistinguishable matter an\nelement of difference so pervading and so persistent has been impressed,\nthat, of them all, not one is interchangeable with another! Each seed\nfeeds its own kind. The protoplasm of the gnat will no more grow into\nthe fly than it will grow into an elephant. Protoplasm is protoplasm:\nyes, but man\u2019s protoplasm is man\u2019s protoplasm, and the mushroom\u2019s the\nmushroom\u2019s. In short, it is quite evident that the word modification, if\nit would conceal, is powerless to withdraw, the difference; which\ndifference, moreover, is one of kind and not of degree.\n\nThis consideration of possible objections, then, is the last we have to\nattend to; and it only remains to draw the general conclusion. All\nanimal and vegetable organisms are alike in power, in form, and in\nsubstance, only if the protoplasm of which they are composed is\nsimilarly alike; and the functions of all animal and vegetable organisms\nare but properties of the molecular affections of their chemical\nconstituents, only if the functions of the protoplasm, of which they are\ncomposed, are but properties of the molecular affections of _its_\nchemical constituents. In disproof of the affirmative in both clauses,\nthere has been no object but to demonstrate, on the one hand, the\ninfinite non-identity of protoplasm, and, on the other, the dependence\nof its functions upon other factors than its molecular constituents.\n\nIn short, the whole position of Mr. Huxley, that all organisms consist\nalike of the same life-matter, which life-matter is, for its part, due\nonly to chemistry, must be pronounced untenable\u2014nor less untenable the\nmaterialism he would found on it.\n\n\n------------------------------------------------------------------------\n\n\n\n\n                   _ON THE HYPOTHESIS OF EVOLUTION_:\n\n                       PHYSICAL AND METAPHYSICAL.\n\n\n\n\n------------------------------------------------------------------------\n\n\n\n\n                                 ON THE\n\n                        HYPOTHESIS OF EVOLUTION:\n\n                      _PHYSICAL AND METAPHYSICAL_.\n\n\u201cMan shall not live by bread alone, but by every word that proceedeth\n    out of the mouth of God shall man live.\u201d ch-hd-end There is\n    apparently considerable repugnance in the minds of many excellent\n    people to the acceptance, or even consideration, of the hypothesis\n    of development, or that of the gradual creation by descent, with\n    modification from the simplest beginnings, of the different forms of\n    the organic world. This objection probably results from two\n    considerations: first, that the human species is certainly involved,\n    and man\u2019s descent from an ape asserted; and, secondly, that the\n    scheme in general seems to conflict with that presented by the\n    Mosaic account of the Creation, which is regarded as communicated to\n    its author by an infallible inspiration.\n\n    As the truth of the hypothesis is held to be infinitely probable by\n    a majority of the exponents of the natural sciences at the present\n    day, and is held as absolutely demonstrated by another portion, it\n    behooves those interested to restrain their condemnation, and on the\n    other hand to examine its evidences, and look any consequent\n    necessary modification of our metaphysical or theological views\n    squarely in the face.\n\n    The following pages state a few of the former; if they suggest some\n    of the latter, it is hoped that they may be such as any logical mind\n    would deduce from the premises. That they will coincide with the\n    spirit of the most advanced Christianity, I have no doubt; and that\n    they will add an appeal through the reason to that direct influence\n    of the Divine Spirit which should control the motives of human\n    action, seems an unavoidable conclusion.\n\n\n                         I. PHYSICAL EVOLUTION.\n\n    It is well known that a species is usually represented by a great\n    number of individuals, distinguished from all other similar\n    associations by more or less numerous points of structure, color,\n    size, etc., and by habits and instincts also, to a certain extent;\n    that the individuals of such associations reproduce their like, and\n    cannot be produced by individuals of associations or species which\n    present differences of structure, color, etc., as defined by\n    naturalists; that the individuals of any such series or species are\n    incapable of reproducing with those of any other species, with some\n    exceptions; and that in the latter cases the offspring are usually\n    entirely infertile.\n\n    The hypothesis of Cuvier assumes that each species was created by\n    Divine power as we now find it at some definite point of geologic\n    time. The paleontologist holding this view sees, in accordance\n    therewith, a succession of creations and destructions marking the\n    history of life on our planet from its commencement.\n\n    The development hypothesis states that all existing species have\n    been derived from species of pre\u00ebxistent geological periods, as\n    offspring or by direct descent; that there have been no total\n    destructions of life in past time, but only a transfer of it from\n    place to place, owing to changes of circumstance; that the types of\n    structure become simpler and more similar to each other as we trace\n    them from later to earlier periods; and that finally we reach the\n    simplest forms consistent with one or several original parent types\n    of the great divisions into which living beings naturally fall.\n\n    It is evident, therefore, that the hypothesis does not include\n    change of species by hybridization, nor allow the descent of living\n    species from any other _living_ species: both these propositions are\n    errors of misapprehension or misrepresentation.\n\n    In order to understand the history of creation of a complex being,\n    it is necessary to analyze it and ascertain of what it consists. In\n    analyzing the construction of an animal or plant we readily arrange\n    its characters into those which it possesses in common with other\n    animals or plants, and those in which it resembles none other: the\n    latter are its _individual_ characters, constituting its\n    individuality. Next we find a large body of characters, generally of\n    a very obvious kind, which it possesses in common with a generally\n    large number of individuals, which, taken collectively, all men are\n    accustomed to call a species; these characters we consequently name\n    _specific_. Thirdly, we find characters, generally in parts of the\n    body which are of importance in the activities of the animal, or\n    which lie in near relation to its mechanical construction in\n    details, which are shared by a still larger number of individuals\n    than those which were similar in specific characters. In other\n    words, it is common to a large number of species. This kind of\n    character we call _generic_, and the grouping it indicates is a\n    genus.\n\n    Farther analysis brings to light characters of organism which are\n    common to a still greater number of individuals; this we call a\n    _family_ character. Those which are common to still more numerous\n    individuals are the _ordinal_: they are usually found in parts of\n    the structure which have the closest connection with the whole\n    life-history of the being. Finally, the individuals composing many\n    orders will be found identical in some important character of the\n    systems by which ordinary life is maintained, as in the nervous and\n    circulatory: the divisions thus outlined are called _classes_.\n\n    By this process of analysis we reach in our animal or plant those\n    peculiarities which are common to the whole animal or vegetable\n    kingdom, and then we have exhausted the structure so completely that\n    we have nothing remaining to take into account beyond the\n    cell-structure or homogeneous protoplasm by which we know that it is\n    organic, and not a mineral.\n\n    The history of the origin of a type, as species, genus, order, etc.,\n    is simply the history of the origin of the structure or structures\n    which define those groups respectively. It is nothing more nor less\n    than this, whether a man or an insect be the object of\n    investigation.\n\n\n                        EVIDENCES OF DERIVATION.\n\n                       \u03b1. Of Specific Characters.\n\n    The evidences of derivation of species from species, within the\n    limits of the genus, are abundant and conclusive. In the first\n    place, the rule which naturalists observe in defining species is a\n    clear consequence of such a state of things. It is not amount and\n    degree of difference that determine the definition of species from\n    species, but it is the _permanency_ of the characters in all cases\n    and under all circumstances. Many species of the systems include\n    varieties and extremes of form, etc., which, were they at all times\n    distinct, and not connected by intermediate forms, would be\n    estimated as species by the same and other writers, as can be easily\n    seen by reference to their works.\n\n    Thus, species are either \u201crestricted\u201d or \u201cprotean,\u201d the latter\n    embracing many, the former few variations; and the varieties\n    included by the protean species are often as different from each\n    other in their typical forms as are the \u201crestricted\u201d species. As an\n    example, the species _Homo sapiens_ (man) will suffice. His primary\n    varieties are as distinct as the species of many well-known genera,\n    but cannot be defined, owing to the existence of innumerable\n    intermediate forms between them.\n\n    As to the common origin of such \u201cvarieties\u201d of the protean species,\n    naturalists never had any doubt, yet when it comes to the restricted\n    \u201cspecies,\u201d the anti-developmentalist denies it _in toto_. Thus the\n    varieties of most of the domesticated animals are some of them\n    known\u2014others held with great probability to have had a common\n    origin. Varieties of plumage in fowls and canaries are of every-day\n    occurrence, and are produced under our eyes. The cart-horse and\n    racer, the Shetland pony and the Norman, are without doubt derived\n    from the same parentage. The varieties of pigeons and ducks are of\n    the same kind, but not every one is aware of the extent and amount\n    of such variations. The varieties in many characters seen in hogs\n    and cattle, especially when examples from distant countries are\n    compared, are very striking, and are confessedly equal in degree to\n    those found to _define_ species in a state of nature: here, however,\n    they are not _definitive_.\n\n    It is easy to see that all that is necessary to produce in the mind\n    of the anti-developmentalist the illusion of distinct origin by\n    creation of many of these forms, would be to destroy a number of the\n    intermediate conditions of specific form and structure, and thus to\n    leave remaining definable groups of individuals, and therefore\n    \u201cspecies.\u201d\n\n    That such destructions and extinctions have been going on ever since\n    the existence of life on the globe is well known. That it should\n    affect intermediate forms, such as bind together the types of a\n    protean species as well as restricted species, is equally certain.\n    That its result has been to produce _definable_ species cannot be\n    denied, especially in consideration of the following facts: Protean\n    species nearly always have a wide geographical distribution. They\n    exist under more varied circumstances than do individuals of a more\n    restricted species. The subordinate variations of the protean\n    species are generally, like the restricted species, confined to\n    distinct subdivisions of the geographical area which the whole\n    occupies. As in geological time changes of level have separated\n    areas once continuous by bodies of water or high mountain ranges, so\n    have vast numbers of individuals occupying such areas been\n    destroyed. Important alterations of temperature, or great changes in\n    abundance or character of vegetable life over given areas, would\n    produce the same result.\n\n    This part of the subject might be prolonged, were it necessary, but\n    it has been ably discussed by Darwin. The _rationale_ of the \u201corigin\n    of species\u201d as stated by him may be examined a few pages farther on.\n\n                 \u03b2. Of the Characters of Higher Groups.\n\n    _a. Relations of Structures._ The evidences of derivative origin of\n    the structures defining the groups called genera, and all those of\n    higher grade, are of a very different character from those discussed\n    in relation to specific characters; they are more difficult of\n    observation and explanation.\n\n    Firstly: It would appear to be supposed by many that the creation of\n    organic types was an irregular and capricious process, variously\n    pursued by its Author as regards time and place, and without\n    definite final aim; and this notwithstanding the wonderful evidences\n    we possess, in the facts of astronomy, chemistry, sound, etc., of\n    His adhesion to harmonious and symmetrical sequences in His modes\n    and plans.\n\n    Such regularity of plan is found to exist in the relations of the\n    great divisions of the animal and vegetable kingdoms as at present\n    existing on the earth. Thus, with animals we have a great class of\n    species which consists of nothing more than masses or cells of\n    protoplasmic matter, without distinct organs; or the Protozoa. We\n    have then the C\u0153lenterata (example, corals,) where the organism is\n    composed of many cells arranged in distinct parts, but where a\n    single very simple system of organs, forming the only internal\n    cavity of the body, does the work of the many systems of the more\n    complex animals. Next, the Echinodermata (such as star-fish) present\n    us with a body containing distinct systems of organs enclosed in a\n    visceral cavity, including a rudimental nervous system in the form\n    of a ring. In the Molluscs to this condition is added additional\n    complication, including extensions of the nervous system from the\n    ring as a starting-point, and a special organ for a heart. In the\n    Articulates (crabs, insects,) we have like complications, and a long\n    distinct nervous axis on the lower surface of the body. The last\n    branch or division of animals is considered to be higher, because\n    all the systems of life organs are most complex or specialized. The\n    nervous ring is almost obliterated by a great enlargement of its\n    usual ganglia, thus become a brain, which is succeeded by a long\n    axis on the upper side of the body. This and other points define the\n    Vertebrata.\n\n    Plans of structure, independent of the simplicity or perfection of\n    the special arrangement or structure of organs, also define these\n    great groups. Thus the Protozoa present a spiral, the C\u0153lenterata a\n    radiate, the Echinodermata a bilateral radiate plan. The Articulates\n    are a series of external rings, each in one or more respects\n    repeating the others. The Molluscs are a sac, while a ring above a\n    ring, joined together by a solid center-piece, represents the plan\n    of each of the many segments of the Vertebrates which give the\n    members of that branch their form.\n\n    These bulwarks of distinction of animal types are entered into here\n    simply because they are the most inviolable and radical of those\n    with which we have to deal, and to give the anti-developmentalist\n    the best foothold for his position. I will only allude to the\n    relations of their points of approach, as these are affected by\n    considerations afterward introduced.\n\n    The Vertebrates approach the Molluscs at the lowest extreme of the\n    former and higher of the latter. The lamprey eels of the one possess\n    several characters in common with the cuttle-fish or squids of the\n    latter. The amphioxus is called the lowest Vertebrate, and though it\n    is nothing else, the definition of the division must be altered to\n    receive it; it has no brain!\n\n    The lowest forms of the Molluscs and Articulates are scarcely\n    distinguishable from each other, so far as adhesion to the \u201cplan\u201d is\n    concerned, and some of the latter division are very near certain\n    Echinodermata. As we approach the boundary-lines of the two lowest\n    divisions, the approaches become equally close, and the boundaries\n    very obscure.\n\n    More instructive is the evidence of the relation of the subordinate\n    classes of any one of these divisions. The conditions of those\n    organs or parts which define classes exhibit a regular relation,\n    commencing with simplicity and ending with complication; first\n    associated with weak exhibitions of the highest functions of the\n    nervous system\u2014at the last displaying the most exalted traits found\n    in the series.\n\n    For example: In the classes of Vertebrates we find the lowest\n    nervous system presents great simplicity\u2014the brain cannot be\n    recognized; next (in lampreys), the end of the nervous axis is\n    subdivided, but scarcely according to the complex type that follows.\n    In fishes the cerebellum and cerebral hemispheres are minute, and\n    the intermediate or optic lobes very large: in the reptiles the\n    cerebral hemispheres exceed the optic lobes, while the cerebellum is\n    smaller. In birds the cerebellum becomes complex and the cerebrum\n    greatly increases. In mammals the cerebellum increases in complexity\n    or number of parts, the optic lobes diminish, while the cerebral\n    hemispheres become wonderfully complex and enlarged, bringing us to\n    the highest development, in man.\n\n    The history of the circulatory system in the Vertebrates is the\n    same.[45] First, a heart with one chamber, then one with two\n    divisions: three divisions belong to a large series, and the highest\n    possess four. The origins of the great artery of the body, the\n    aorta, are first five on each side: they lose one in the succeeding\n    class in the ascending scale, and one in each succeeding class or\n    order, till the Mammalia, including man, present us with but one on\n    one side.\n\nFootnote 45:\n\n      See a homological system of the circulatory system in the author\u2019s\n      Origin of Genera, p. 22.\n\n    From an infinitude of such considerations as the above, we derive\n    the certainty that the general arrangement of the various groups of\n    the organic world is in scales, the subordinate within the more\n    comprehensive divisions. The identification of all the parts in such\n    a complexity of organism as the highest animals present, is a matter\n    requiring much care and attention, and constitutes the study of\n    homologies. Its pursuit has resulted in the demonstration that every\n    individual of every species of a given branch of the animal kingdom\n    is composed of elements common to all, and that the differences\n    which are so radical in the higher groups are but the modifications\n    of the same elemental parts, representing completeness or\n    incompleteness, obliteration or subdivision. Of the former character\n    are rudimental organs, of which almost every species possesses an\n    example in some part of its structure.\n\n    But we have other and still more satisfactory evidence of the\n    meaning of these relations. By the study of embryology we can prove\n    most indubitably that the simple and less complex are inferior to\n    the more complex. Selecting the Vertebrates again as an example, the\n    highest form of mammal\u2014_e.g._, man\u2014presents in his earliest stages\n    of embryonic growth a skeleton of cartilage, like that of the\n    lamprey: he also possesses five origins of the aorta and five slits\n    on the neck, both which characters belong to the lamprey and the\n    shark. If the whole number of these parts does not coexist in the\n    embryonic man, we find in embryos of lower forms more nearly related\n    to the lamprey that they do. Later in the life of the mammal but\n    four aortic origins are found, which arrangement, with the heart now\n    divided into two chambers, from a beginning as a simple tube, is\n    characteristic of the class of Vertebrates next in order\u2014the bony\n    fishes. The optic lobes of the human brain have also at this time a\n    great predominance in size\u2014a character above stated to be that of\n    the same class. With advancing development the infant mammal follows\n    the scale already pointed out. Three chambers of the heart and three\n    aortic origins follow, presenting the condition permanent in the\n    batrachia; and two origins, with enlarged cerebral hemispheres of\n    the brain, resemble the reptilian condition. Four heart-chambers,\n    and one aortic root on each side, with slight development of the\n    cerebellum, follow all characters defining the crocodiles, and\n    immediately precede the special conditions defining the mammals.\n    These are, the single aorta root from one side, and the full\n    development of the cerebellum: later comes that of the cerebrum also\n    in its higher mammalian and human traits.\n\n    Thus we see the order already pointed out to be true, and to be an\n    ascending one. This is the more evident as each type or class passes\n    through the conditions of those below it, as did the mammal; each\n    scale being shorter as its highest terminus is lower. Thus the\n    crocodile passes through the stage of the lamprey, the fish, the\n    batrachian and the reptile proper.\n\n    _b. In Time._ We have thus a scale of relations of existing forms of\n    animals and plants of a remarkable kind, and such as to stimulate\n    greatly our inquiries as to its significance. When we turn to the\n    remains of the past creation preserved to us in the deposits\n    continued throughout geologic time, we are not disappointed, for\n    great light is at once thrown upon the subject.\n\n    We find, in brief, that the lowest division of the animal kingdom\n    appeared first, and long before any type of a higher character was\n    created. The Protozo\u00f6n, Eozo\u00f6n, is the earliest of animals in\n    geologic time, and represents the lowest type of animal life now\n    existing. We learn also that the highest branch appeared last. No\n    remains of Vertebrates have been found below the lower Devonian\n    period, or not until the Echinoderms and Molluscs had reached a\n    great pre\u00ebminence. It is difficult to be sure whether the Protozoa\n    had a greater numerical extent in the earliest periods than now, but\n    there can be no doubt that the C\u0153lenterata (corals) and Echinoderms\n    (crinoids) greatly exceeded their present bounds, in Paleozoic time,\n    so that those at present existing are but a feeble remnant. If we\n    examine the subdivisions known as classes, evidence of the nature of\n    the succession of creation is still more conclusive. The most\n    polyp-like of the Molluscs (brachiopoda) constituted the great mass\n    of its representatives during Paleozoic time. Among Vertebrates the\n    fishes appear first, and had their greatest development in size and\n    numbers during the earliest periods of the existence of the\n    division. Batrachia were much the largest and most important of land\n    animals during the Carboniferous period, while the higher\n    Vertebrates were unknown. The later Mesozoic periods saw the reign\n    of reptiles, whose position in structural development has been\n    already stated. Finally, the most perfect, the mammal, came upon the\n    scene, and in his humblest representatives. In Tertiary times\n    mammalia supplanted the reptiles entirely, and the unspiritual\n    mammals now yield to man, the only one of his class in whom the\n    Divine image appears.\n\n    Thus the structural relations, the embryonic characters, and the\n    successive appearance in time of animals coincide. The same is very\n    probably true of plants.\n\n    That the existing state of the geological record of organic types\n    should be regarded as anything but a fragment is, from our\n    stand-point, quite preposterous. And more, it may be assumed with\n    safety that when completed it will furnish us with a series of\n    regular successions, with but slight and regular interruptions, if\n    any, from the species which represented the simplest beginnings of\n    life at the dawn of creation, to those which have displayed\n    complication and power in later or in the present period.\n\n    For the labors of the paleontologist are daily bringing to light\n    structures intermediate between those never before so connected, and\n    thus creating lines of succession where before were only\n    interruptions. Many such instances might be adduced: two may be\n    selected as examples from American paleontology;[46] _i.e._, the\n    near approach to birds made by the reptiles L\u00e6laps and Megadactylus;\n    and the combination of characters of the sub-orders of Cryptodire\n    and Pleurodire Tortoises in the Adocus of New Jersey.\n\nFootnote 46:\n\n      Professor Huxley, in the last anniversary lecture before the\n      Geological Society of London, recalls his opinion, enunciated in\n      1862, that \u201cthe positively-ascertained truths of Paleontology\u201d\n      negative \u201cthe doctrines of progressive modification, which suppose\n      that modification to have taken place by a necessary progress from\n      more to less embryonic forms, from more to less generalized types,\n      within the limits of the period represented by the fossiliferous\n      rocks; that it shows no evidence of such modification; and as to\n      the nature of that modification, it yields no evidence whatsoever\n      that the earlier members of any long-continued group were more\n      generalized in structure than the later ones.\u201d\n\n      Respecting this position, he says: \u201cThus far I have endeavored to\n      expand and enforce by fresh arguments, but not to modify in any\n      important respect, the ideas submitted to you on a former\n      occasion. But when I come to the propositions respecting\n      progressive modification, it appears to me, with the help of the\n      new light which has broken from various quarters, that there is\n      much ground for softening the somewhat Brutus-like severity with\n      which I have dealt with a doctrine for the truth of which I should\n      have been glad enough to be able to find a good foundation in\n      1862. So far indeed as the Invertebrata and the lower Vertebrata\n      are concerned, the facts, and the conclusions which are to be\n      drawn from them, appear to me to remain what they were. For\n      anything that as yet appears to the contrary, the earliest known\n      marsupials may have been as highly organized as their living\n      congeners; the Permian lizards show no signs of inferiority to\n      those of the present day; the labyrinthodonts cannot be placed\n      below the living salamander and triton; the Devonian ganoids are\n      closely related to polypterus and lepidosiren.\u201d\n\n      To this it may be replied: 1. The scale of progression of the\n      Vertebrata is measured by the conditions of the circulatory\n      system, and in some measure by the nervous, and not by the\n      osseous: tested by this scale, there has been successional\n      complication of structure among Vertebrata in time. 2. The\n      question with the evolutionist is, not what types have persisted\n      to the present day, but the order in which types appeared in time.\n      3. The Marsupials, Permian saurians, labyrinthodonts and Devonian\n      ganoids are remarkably generalized groups, and predecessors of\n      types widely separated in the present period. 4. Professor Huxley\n      adduces many such examples among the mammalian subdivisions in the\n      remaining portion of his lecture. 5. Two alternatives are yet open\n      in the explanation of the process of evolution: since generalized\n      types, which combine the characters of higher and lower groups of\n      later periods, must thus be superior to the lower, the lower must\n      (first) be descended from such a generalized form by degradation;\n      or (second) not descended from it at all, but from some lower\n      contemporaneous type by advance; the higher only of the two being\n      derived from the first-mentioned. The last I suspect to be a true\n      explanation, as it is in accordance with the homologous groups.\n      This law will shorten the demands of paleontologists for time,\n      since, instead of deriving all reptilia, batrachia, etc., from\n      common origins, it points to the derivation of higher reptilia of\n      a higher order from higher reptilia of a lower order, lower\n      reptilia of the first from lower reptilia of the second; finally,\n      the several groups of the lowest or most generalized order of\n      reptilia from a parallel series of the class below, or batrachia.\n\n    We had no more reason to look for intermediate or connecting forms\n    between such types as these, than between any others of similar\n    degree of remove from each other with which we are acquainted. And\n    inasmuch as almost all groups, as genera, orders, etc., which are\n    held to be distinct, but adjacent, present certain points of\n    approximation to each other, the almost daily discovery of\n    intermediate forms gives us confidence to believe that the pointings\n    in other cases will also be realized.\n\n                           \u03b3. Of Transitions.\n\n    The preceding statements were necessary to the comprehension of the\n    supposed mode of metamorphosis or development of the various types\n    of living beings, or, in other words, of the single structural\n    features which define them.... As it is evident that the more\n    comprehensive groups, or those of highest rank, have had their\n    origin in remote ages, cases of transition from one to the other by\n    change of character cannot be witnessed at the present day. We\n    therefore look to the most nearly related divisions, or those of the\n    lowest rank, for evidence of such change.\n\n    It is necessary to premise that embryology teaches that all the\n    species of a given branch of the animal kingdom (_e.g._, Vertebrate,\n    Mollusc, etc.) are quite identical in structural character at their\n    first appearance on the germinal layer of the yolk of the parent\n    egg. It shows that the character of the respective groups of high\n    rank appear first, then those of less grade, and last of all those\n    structures which distinguish them as genera. But among the earliest\n    characters which appear are those of the species, and some of those\n    of the individual.\n\n    We find the characters of different _genera_ to bear the same\n    relation to each other that we have already seen in the case of\n    those definitive of orders, etc. In a natural assemblage of related\n    genera we discover that some are defined by characters found only in\n    the embryonic stages of others; while a second will present a\n    permanent condition of its definitive part, which marks a more\n    advanced stage of that highest. In this manner many stages of the\n    highest genus appear to be represented by permanent genera in all\n    natural groups. Generally, however, this resemblance does not\n    involve, an entire identity, there being some other immaturities\n    found in the highest genus at the time it presents the character\n    preserved in permanency by the lower, which the lower loses. Thus\n    (to use a very coarse example) a frog at one stage of growth has\n    four legs and a tail: the salamander always preserves four legs and\n    a tail, thus resembling the young frog. The latter is, however, not\n    a salamander at that time, because, among other things, the skeleton\n    is represented by cartilage only, and the salamander\u2019s is ossified.\n    This relation is therefore an imitation only, and is called _inexact\n    parallelism_.\n\n    As we compare nearer and nearer relations\u2014_i.e._, the genera which\n    present fewest points of difference\u2014we find the differences between\n    undeveloped stages of the higher and permanent conditions of the\n    lower to grow fewer and fewer, until we find numerous instances\n    where the lower genus is exactly the same as the undeveloped stage\n    of the higher. This relation is called that of _exact parallelism_.\n\n    It must now be remembered that the permanence of a character is what\n    gives it its value in defining genus, order, etc., in the eyes of\n    the systematist. So long as the condition is permanent no transition\n    can be seen: there is therefore no development. If the condition is\n    transitional, it defines nothing, and nothing is developed; at\n    least, so says the anti-developmentalist. It is the old story of the\n    settler and the Indian: \u201cWill you take owl and I take turkey, or I\n    take turkey and you owl?\u201d\n\n    If we find a relation of _exact parallelism_ to exist between two\n    sets of species in the condition of a certain organ, and the\n    difference so expressed the only one which distinguishes them as\n    sets from each other\u2014if that condition is always the same in each\n    set\u2014we call them two genera: if in any species the condition is\n    variable at maturity, or sometimes the undeveloped condition of the\n    part is persistent and sometimes transitory, the sets characterized\n    by this difference must be united by the systematist, and the whole\n    is called a single genus.\n\n    We know numerous cases where different individuals of the same\n    species present this relation of _exact parallelism_ to each other;\n    and as we ascribe common origin to the individuals of a species, we\n    are assured that the condition of the inferior individual is, in\n    this case, simply one of repressed growth, or a failure to fulfill\n    the course accomplished by the highest. Thus, certain species of the\n    salamandrine genus amblystoma undergo a metamorphosis involving\n    several parts of the osseous and circulatory systems, etc., while\n    half grown; others delay it till fully grown; one or two species\n    remain indifferently unchanged or changed, and breed in either\n    condition, while another species breeds unchanged, and has never\n    been known to complete a metamorphosis.\n\n    The nature of the relation of _exact parallelism_ is thus explained\n    to be that of checked or advanced growth of individuals having a\n    common origin. The relation of _inexact parallelism_ is readily\n    explained as follows: With a case of _exact parallelism_ in the\n    mind, let the repression producing the character of the lower,\n    parallelize the latter with a stage of the former in which a second\n    part is not quite mature: we will have a slight want of\n    correspondence between the two. The lower will be immature in but\n    one point, the incompleteness of the higher being seen in two\n    points. If we suppose the immaturity to consist in a repression at a\n    still earlier point in the history of the higher, the latter will be\n    undeveloped in other points also: thus, the spike-horned deer of\n    South America have the horn of the second year of the North American\n    genus. They would be generically identical with that stage of the\n    latter, were it not that these still possess their milk dentition at\n    two years of age. In the same way the nature of the parallelisms\n    seen in higher groups, as orders, etc., may be accounted for.\n\n    The theory of homologous groups furnishes important evidence in\n    favor of derivation. Many orders of animals (probably all, when we\n    come to know them) are divisible into two or more sections, which I\n    have called _homologous_. These are series of genera or families,\n    which differ from each other by some marked character, but whose\n    contained genera or families differ from each other in the same\n    points of detail, and in fact correspond exactly. So striking is\n    this correspondence that were it not for the general and common\n    character separating the homologous series, they would be regarded\n    as the same, each to each. Now it is remarkable that where studied\n    the difference common to all the terms of two homologous groups is\n    found to be one of _inexact parallelism_, which has been shown above\n    to be evidence of descent. Homologous groups always occupy different\n    geographical areas on the earth\u2019s surface, and their relation is\n    precisely that which holds between successive groups of life in the\n    periods of geologic time.\n\n    In a word, we learn from this source that distinct geologic epochs\n    coexist at the same time on the earth. I have been forced to this\n    conclusion[47] by a study of the structure of terrestrial life, and\n    it has been remarkably confirmed by the results of recent deep-sea\n    dredgings made by the United States Coast Survey in the Gulf Stream,\n    and by the British naturalists in the North Atlantic. These have\n    brought to light types of Tertiary life, and of even the still more\n    ancient Cretaceous periods, living at the present day. That this\n    discovery invalidates in any wise the conclusions of geology\n    respecting lapse of time is an unwarranted assumption that some are\n    forward to make. If it changes the views of some respecting the\n    parallelism or co\u00ebxistence of faun\u00e6 in different regions of the\n    earth, it is only the anti-developmentalists whose position must be\n    changed.\n\nFootnote 47:\n\n      _Origin of Genera_, pages 70, 77, 79.\n\n    For, if we find distinct geologic faun\u00e6, or epochs defined by faun\u00e6,\n    co\u00ebxisting during the present period, and fading or emerging into\n    one another as they do at their geographical boundaries, it is proof\n    positive that the geologic epochs and periods of past ages had in\n    like manner no trenchant boundaries, but also passed the one into\n    the other. The assumption that the apparent interruptions are the\n    result of transfer of life rather than destruction, or of want of\n    opportunities of preservation, is no doubt the true one.\n\n                      \u03b4. Rationale of Development.\n\n    _a. In Characters of Higher Groups._ It is evident in the case of\n    the species in which there is an irregularity in the time of\n    completion of metamorphosis that some individuals traverse a longer\n    developmental line than those who remain more or less incomplete. As\n    both accomplish growth in the same length of time, it is obvious\n    that it proceeds with greater rapidity in one sense in that which\n    accomplishes most: its growth is said to be accelerated. This\n    phenomenon is especially common among insects, where the females of\n    perfect males are sometimes larv\u00e6 or nearly so, or pup\u00e6, or lack\n    wings or some character of final development. Quite as frequently,\n    some males assume characters in advance of others, sometimes in\n    connection with a peculiar geographical range.\n\n    In cases of _exact parallelism_ we reasonably suppose the cause to\n    be the same, since the conditions are identical, as has been shown;\n    that is, the higher conditions have been produced by a crowding back\n    of the earlier characters and an acceleration of growth, so that a\n    given succession in order of advance has extended over a longer\n    range of growth than its predecessor in the same allotted time. That\n    allotted time is the period before maturity and reproduction, and it\n    is evident that as fast as modifications or characters should be\n    assumed sufficiently in advance of that period, so certainly would\n    they be conferred upon the offspring by reproduction. The\n    _acceleration_ in the assumption of a character, progressing more\n    rapidly than the same in another character, must soon produce, in a\n    type whose stages were once the exact parallel of a permanent lower\n    form, the condition of _inexact parallelism_. As all the more\n    comprehensive groups present this relation to each other, we are\n    compelled to believe that _acceleration_ has been the principle of\n    their successive evolution during the long ages of geologic time.\n\n    Each type has, however, its day of supremacy and perfection of\n    organism, and a retrogression in these respects has succeeded. This\n    has no doubt followed a law the reverse of acceleration, which has\n    been called _retardation_. By the increasing slowness of the growth\n    of the individuals of a genus, and later and later assumption of the\n    characters of the latter, they would be successively lost.\n\n    To what power shall we ascribe this acceleration, by which the first\n    beginnings of structure have accumulated to themselves through the\n    long geologic ages complication and power, till from the germ that\n    was scarcely born into a sand-lance, a human being climbed the\n    complete scale, and stood easily the chief of the whole?\n\n    In the cases of species, where some individuals develop farther than\n    others, we say the former possess more growth-force, or \u201cvigor,\u201d\n    than the latter. We may therefore say that higher types of structure\n    possess more \u201cvigor\u201d than the lower. This, however, we do not know\n    to be true, nor can we readily find means to demonstrate it.\n\n    The food which is taken by an adult animal is either assimilated, to\n    be consumed in immediate activity of some kind, or stored for future\n    use, and the excess is rejected from the body. We have no reason to\n    suppose that the same kind of material could be made to subserve the\n    production of life-force by any other means than that furnished by a\n    living animal organism. The material from which this organism is\n    constructed is derived first from the parent, and afterward from the\n    food, etc., assimilated by the individual itself so long as growth\n    continues. As it is the activity of assimilation directed to a\n    special end during this latter period which we suppose to be\n    increased in accelerated development, the acceleration is evidently\n    not brought about by increased facilities for obtaining the means of\n    life which the same individual possesses as an adult. That it is not\n    in consequence of such increased facilities possessed by its parents\n    over those of the type preceding it, seems equally improbable when\n    we consider that the characters in which the parent\u2019s advance has\n    appeared are rarely of a nature to increase those facilities.\n\n    The nearest approach to an explanation that can be offered appears\n    to be somewhat in the following direction:\n\n    There is every reason to believe that the character of the\n    atmosphere has gradually changed during geologic time, and that\n    various constituents of the mixture have been successively removed\n    from it, and been stored in the solid material of the earth\u2019s crust\n    in a state of combination. Geological chemistry has shown that the\n    cooling of the earth has been accompanied by the precipitation of\n    many substances only gaseous at high temperatures. Hydrochloric and\n    sulphuric acids have been transferred to mineral deposits or aqueous\n    solutions. The removal of carbonic acid gas and the vapor of water\n    has been a process of much slower progress, and after the expiration\n    of all the ages a proportion of both yet remains. Evidence of the\n    abundance of the former in the earliest periods is seen in the vast\n    deposits of limestone rock; later, in the prodigious quantities of\n    shells which have been elaborated from the same in solution. Proof\n    of its abundance in the atmosphere in later periods is seen in the\n    extensive deposits of coal of the Carboniferous, Triassic and\n    Jurassic periods. If the most luxuriant vegetation of the present\n    day takes but fifty tons of carbon from the atmosphere in a century,\n    per acre, thus producing a layer over that extent of less than a\n    third of an inch in thickness, what amount of carbon must be\n    abstracted in order to produce strata of thirty-five feet in depth?\n    No doubt it occupied a long period, but the atmosphere, thus\n    deprived of a large proportion of carbonic acid, would in subsequent\n    periods undoubtedly possess an improved capacity for the support of\n    animal life.\n\n    The successively higher degree of oxidization of the blood in the\n    organs designed for that function, whether performing it in water or\n    air, would certainly accelerate the performances of all the vital\n    functions, and among others that of growth. Thus it may be that\n    _acceleration_ can be accounted for, and the process of the\n    development of the orders and sundry lesser groups of the Vertebrate\n    kingdom indicated; for, as already pointed out, the definitions of\n    such are radically placed in the different structures of the organs\n    which aerate the blood and distribute it to its various\n    destinations.\n\n    But the great question, What determined the direction of this\n    acceleration? remains unanswered. One cannot understand why more\n    highly-oxidized blood should hasten the growth of partition of the\n    ventricle of the heart in the serpent, the more perfectly to\n    separate the aerated from the impure fluid; nor can we see why a\n    more perfectly-constructed circulatory system, sending purer blood\n    to the brain, should direct accelerated growth to the cerebellum or\n    cerebral hemispheres in the crocodile.\n\n    _b. In Characters of the Specific Kind._ Some of the characters\n    usually placed in the specific category have been shown to be the\n    same in kind as those of higher categories. The majority are,\n    however, of a different kind, and have been discussed several pages\n    back.\n\n    The cause of the origin of these characters is shrouded in as much\n    mystery as that of those which have occupied the pages immediately\n    preceding. As in that case, we have to assume, as Darwin has done, a\n    tendency in Nature to their production. This is what he terms \u201cthe\n    principle of variation.\u201d Against an unlimited variation the great\n    law of heredity or atavism has ever been opposed, as a conservator\n    and multiplier of type. This principle is exemplified in the fact\n    that like produces like\u2014that children are like their parents,\n    frequently even in minuti\u00e6. It may be compared to habit in\n    metaphysical matters, or to that singular love of time or rhythm\n    seen in man and lower animals, in both of which the tendency is to\n    repeat in continual cycles a motion or state of the mind or sense.\n\n    Further, but a proportion of the lines of variation is supposed to\n    have been perpetuated, and the extinction of intermediate forms, as\n    already stated, has left isolated groups or species.\n\n    The effective cause of these extinctions is stated by Darwin to have\n    been a \u201cnatural selection\u201d\u2014a proposition which distinguishes his\n    theory from other development hypotheses, and which is stated in\n    brief by the expression, \u201cthe preservation of the fittest.\u201d Its\n    meaning is this: that those characters appearing as results of this\n    spontaneous variation which are little adapted to the conflict for\n    subsistence, with the nature of the supply, or with rivals in its\n    pursuit, dwindle and are sooner or later extirpated; while those\n    which are adapted to their surroundings, and favored in the struggle\n    for means of life and increase, predominate, and ultimately become\n    the centers of new variation. \u201cI am convinced,\u201d says Darwin, \u201cthat\n    natural selection has been the main, but not exclusive, means of\n    modification.\u201d\n\n    That it has been to a large extent the means of preservation of\n    those structures known as specific, must, I think, be admitted. They\n    are related to their peculiar surroundings very closely, and are\n    therefore more likely to exist under their influence. Thus, if a\n    given genus extends its range over a continent, it is usually found\n    to be represented by peculiar species\u2014one in a maritime division,\n    another in the desert, others in the forest, in the swamp or the\n    elevated areas of the region. The wonderful interdependence shown by\n    Darwin to exist between insects and plants in the fertilization of\n    the latter, or between animals and their food-plants, would almost\n    induce one to believe that it were the true expression of the whole\n    law of development.\n\n    But the following are serious objections to its universal\n    application:\n\n    First: The characters of the higher groups, from genera up, are\n    rarely of a character to fit their possessors especially for\n    surrounding circumstances; that is, the differences which separate\n    genus from genus, order from order, etc., in the ascending scale of\n    each, do not seem to present a superior adaptation to surrounding\n    circumstances in the higher genus to that seen in the lower genus,\n    etc. Hence, superior adaptation could scarcely have caused their\n    selection above other forms not existing. Or, in other words, the\n    different structures which indicate successional relation, or which\n    measure the steps of progress, seem to be equally well fitted for\n    the same surroundings.\n\n    Second: The higher groups, as orders, classes, etc., have been in\n    each geologic period alike distributed over the whole earth, under\n    all the varied circumstances offered by climate and food. Their\n    characters do not seem to have been modified in reference to these.\n    Species, and often genera, are, on the other hand, eminently\n    restricted according to climate, and consequently vegetable and\n    animal food.\n\n    The law of development which we seek is indeed not that which\n    preserves the higher forms and rejects the lower after their\n    creation, but that which explains why higher forms were created at\n    all. Why in the results of a creation we see any relation of higher\n    and lower, and not rather a world of distinct types, each perfectly\n    adapted to its situation, but none properly higher than another in\n    an ascending scale, is the primary question. Given the principle of\n    advance, then natural selection has no doubt modified the details;\n    but in the successive advances we can scarcely believe such a\n    principle to be influential. _We look rather upon a progress as the\n    result of the expenditure of some force fore-arranged for that end._\n\n    It may become, then, a question whether in characters of high grade\n    the habit or use is not rather the result of the acquisition of the\n    structure than the structure the result of the encouragement offered\n    to its assumed beginnings by use, or by liberal nutrition derived\n    from the increasingly superior advantages it offers.\n\n                     \u03b5. The Physical Origin of Man.\n\n    If the hypothesis here maintained be true, man is the descendant of\n    some pre\u00ebxistent generic type, the which, if it were now living, we\n    would probably call an ape.\n\n    Man and the chimpanzee were in Linn\u00e6us\u2019 system only two species of\n    the same genus, but a truer anatomy places them in separate genera\n    and distinct families. There is no doubt, however, that Cuvier went\n    much too far when he proposed to consider Homo as the representative\n    of an order distinct from the quadrumana, under the name of bimana.\n    The structural differences will not bear any such interpretation,\n    and have not the same value as those distinguishing the orders of\n    mammalia; as, for instance, between carnivora and bats, or the\n    cloven-footed animals and the rodents, or rodents and edentates. The\n    differences between man and the chimpanzee are, as Huxley well puts\n    it, much less than those between the chimpanzee and lower\n    quadrumana, as lemurs, etc. In fact, man is the type of a family,\n    Hominid\u00e6, of the order Quadrumana, as indicated by the characters of\n    the dentition, extremities, brain, etc. The reader who may have any\n    doubts on this score may read the dissections of Geoffroy St.\n    Hilaire, made in 1856, before the issue of Darwin\u2019s _Origin of\n    Species_. He informs us that the brain of man is nearer in structure\n    to that of the orang than the orang\u2019s is to that of the South\n    American howler, and that the orang and howler are more nearly\n    related in this regard than are the howler and the marmoset.\n\n    The modifications presented by man have, then, resulted from an\n    acceleration in development in some respects, and retardation\n    perhaps in others. But until the _combination_ now characteristic of\n    the genus Homo was attained the being could not properly be called\n    man.\n\n    And here it must be observed that as an organic type is\n    characterized by the co\u00ebxistence of a number of peculiarities which\n    have been developed independently of each other, its distinctive\n    features and striking functions are not exhibited until that\n    co\u00ebxistence is attained which is necessary for these ends.\n\n    Hence, the characters of the human genus were probably developed\n    successively; but few of the indications of human superiority\n    appeared until the combination was accomplished. Let the opposable\n    thumb be first perfected, but of what use would it be in human\n    affairs without a mind to direct? And of what use a mind without\n    speech to unlock it? And speech could not be possible though all the\n    muscles of the larynx but one were developed, or but a slight\n    abnormal convexity in one pair of cartilages remained.\n\n    It would be an objection of little weight could it be truly urged\n    that there have as yet no remains of apelike men been discovered,\n    for we have frequently been called upon in the course of\n    paleontological discovery to bridge greater gaps than this, and\n    greater remain, which we expect to fill. But we _have_ apelike\n    characters exhibited by more than one race of men yet existing.\n\n    But the remains of that being which is supposed to have been the\n    progenitor of man may have been discovered a short time since in the\n    cave of Naulette, Belgium, with the bones of the extinct rhinoceros\n    and elephant.\n\n    We all admit the existence of higher and lower races, the latter\n    being those which we now find to present greater or less\n    approximations to the apes. The peculiar structural characters that\n    belong to the negro in his most typical form are of that kind,\n    however great may be the distance of his remove therefrom. The\n    flattening of the nose and prolongation of the jaws constitute such\n    a resemblance; so are the deficiency of the calf of the leg, and the\n    obliquity of the pelvis, which approaches more the horizontal\n    position than it does in the Caucasian. The investigations made at\n    Washington during the war with reference to the physical\n    characteristics of the soldiers show that the arms of the negro are\n    from one to two inches longer than those of the whites: another\n    approximation to the ape. In fact, this race is a species of the\n    genus Homo, as distinct in character from the Caucasian as those we\n    are accustomed to recognize in other departments of the animal\n    kingdom; but he is not distinct by isolation, since intermediate\n    form\u2019s between him and the other species can be abundantly found.\n\n    And here let it be particularly observed that two of the most\n    prominent characters of the negro are those of immature stages of\n    the Indo-European race in its characteristic types. The deficient\n    calf is the character of infants at a very early stage; but, what is\n    more important, the flattened bridge of the nose and shortened nasal\n    cartilages are universally immature conditions of the same parts in\n    the Indo-European. Any one may convince himself of that by examining\n    the physiognomies of infants. In some races\u2014_e.g._, the Slavic\u2014this\n    undeveloped character persists later than in some others. The Greek\n    nose, with its elevated bridge, coincides not only with \u00e6sthetic\n    beauty, but with developmental perfection.\n\n    This is, however, only \u201c_inexact_ parallelism,\u201d as the characters of\n    the hair, etc., cannot be explained on this principle _among\n    existing races_. The embryonic characters mentioned are probably a\n    remnant of those characteristic of the primordial race or species.\n\n    But the man of Naulette, if he be not a monstrosity, in a still more\n    distinct and apelike species. The chin, that marked character of\n    other species of men, is totally wanting, and the dentition is quite\n    approximate to the man-like apes, and different from that of modern\n    men. The form is very massive, as in apes. That he was not abnormal\n    is rendered probable by approximate characters seen in a jaw from\n    the cave of Puy-sur-Aube, and less marked in the lowest races of\n    Australia and New Caledonia.\n\n    As to the single or multiple origin of man, science as yet furnishes\n    no answer. It is very probable that, in many cases, the species of\n    one genus have descended from corresponding species of another by\n    change of generic characters only. It is a remarkable fact that the\n    orang possesses the peculiarly developed malar bones and the copper\n    color characteristic of the Mongolian inhabitants of the regions in\n    which this animal is found, while the gorilla exhibits the\n    prognathic jaws and black hue of the African races near whom he\n    dwells. This kind of geographical imitation is very common in the\n    animal kingdom.\n\n                         \u03b6. The Mosaic Account.\n\n    As some persons imagine that this hypothesis conflicts with the\n    account of the creation of man given in Genesis, a comparison of\n    some of the points involved is made below.\n\n    First: In Genesis i. 26, 27, we read, \u201cAnd God said, Let us make man\n    in our image, after our likeness,\u201d etc. \u201cSo God created man in his\n    own image, in the image of God created he him; male and female\n    created he them.\u201d Those who believe that this \u201cimage\u201d is a physical,\n    material form, are not disposed to admit the entrance of anything\n    apelike into its constitution, for the ascription of any such\n    appearance to the Creator would be impious and revolting. But we are\n    told that \u201cGod is a Spirit,\u201d and Christ said to his disciples after\n    his resurrection, \u201cA spirit hath not flesh and bones, as ye see me\n    have.\u201d Luke xxiv. 39. It will require little further argument to\n    show that a mental and spiritual image is what is meant, as it is\n    what truly exists. Man\u2019s conscience, intelligence and creative\n    ingenuity show that he possesses an \u201cimage of God\u201d within him, the\n    possession of which is really necessary to his limited comprehension\n    of God and of God\u2019s ways to man.\n\n    Second: In Genesis ii. 7, the text reads, \u201cAnd the Lord God formed\n    man of the dust of the ground, and breathed into his nostrils the\n    breath of life; and man became a living soul.\u201d The fact that man is\n    the result of the modification of an apelike predecessor nowise\n    conflicts with the above statement as to the materials of which his\n    body is composed. Independently of origin, if the body of man be\n    composed of dust, so must that of the ape be, since the composition\n    of the two is identical. But the statement simply asserts that man\n    was created of the same materials which compose the earth: their\n    condition as \u201cdust\u201d depending merely on temperature and subdivision.\n    The declaration, \u201cDust thou art, and unto dust thou shalt return,\u201d\n    must be taken in a similar sense, for we know that the decaying body\n    is resolved not only into its earthly constituents, but also into\n    carbonic acid gas and water.\n\n    When God breathed into man\u2019s nostrils the breath of life, we are\n    informed that he became, not a living body, but \u201ca living soul.\u201d His\n    descent from a pre\u00ebxistent being involved the possession of a living\n    body; but when the Creator breathed into him we may suppose for the\n    present that He infused into this body the immortal part, and at\n    that moment man became a conscientious and responsible being.\n\n\n                      II. METAPHYSICAL EVOLUTION.\n\n    It is infinitely improbable that a being endowed with such\n    capacities for gradual progress as man has exhibited, should have\n    been full fledged in accomplishments at the moment when he could\n    first claim his high title, and abandon that of his simious\n    ancestors. We are therefore required to admit the growth of human\n    intelligence from a primitive state of inactivity and absolute\n    ignorance; including the development of one important mode of its\n    expression\u2014speech; as well as that of the moral qualities, and of\n    man\u2019s social system\u2014the form in which his ideas of morality were\n    first displayed.\n\n    The expression \u201cevolution of morality\u201d need not offend, for the\n    question in regard to the _laws_ of this evolution is the really\n    important part of the discussion, and it is to the opposing views on\n    this point that the most serious interest attaches.\n\n                  *       *       *       *       *\n\n    The two views of evolution already treated of, held separately, are\n    quite opposed to each other. The first (and generally received) lays\n    stress on the influence of external surroundings, as the stimulus to\n    and guidance of development: it is the counterpart of Darwin\u2019s\n    principle called Natural Selection in material progress. This might\n    be called the _Conflict theory_. The second view recognizes the\n    workings of a force whose nature we do not know, whose exhibitions\n    accord perfectly with their external surroundings (or other\n    exhibitions of itself), without being under their influence or more\n    related to them, as effect to cause, than the notes of the musical\n    octave or the colors of the spectrum are to each other. This is the\n    _Harmonic theory_. In other words, the first principle deduces\n    perfection from struggle and discord; the second, from the\n    coincident progress of many parts, forming together a divine harmony\n    comparable to music. That these principles are both true is rendered\n    extremely probable by the actual phenomena of development, material\n    and immaterial. In other words, struggle and discord ever await that\n    which is not in the advance, and which fails to keep pace with the\n    harmonious development of the whole.\n\n    All who have studied the phenomena of the creation believe that\n    there exists in it a grand and noble harmony, such as was described\n    to Job when he was told that \u201cthe morning stars sang together, and\n    all the sons of God shouted for joy.\u201d\n\n                    \u03b1. Development of Intelligence.\n\n    If the brain is the organ of mind, we may be surprised to find that\n    the brain of the intelligent man scarcely differs in structure from\n    that of the ape. Whence, then, the difference of power? Though no\n    one will now deny that many of the Mammalia are capable of reasoning\n    upon observed facts, yet how greatly the results of this capacity\n    differ in number and importance from those achieved by human\n    intelligence! Like water at the temperatures of 50\u00b0 and 53\u00b0, where\n    we perceive no difference in essential character, so between the\n    brains of the lower and higher monkeys no difference of function or\n    of intelligence is perceptible. But what a difference do the two\n    degrees of temperature from 33\u00b0 to 31\u00b0 produce in water! In like\n    manner the difference between the brain of the higher ape and that\n    of man is accompanied by a difference in function and power, on\n    which, man\u2019s earthly destiny depends. In development, as with the\n    water so with the higher ape: some Rubicon has been crossed, some\n    floodgate has been opened, which marks one of Nature\u2019s great\n    transitions, such as have been called \u201cExpression points\u201d of\n    progress.\n\n    What point of progress in such a history would account for this\n    accession of the powers of the human intelligence? It has been\n    answered, with considerable confidence, The power of speech. Let us\n    picture man without speech. Each generation would learn nothing from\n    its predecessors. Whatever originality or observation might yield to\n    a man would die with him. Each intellectual life would begin where\n    every other life began, and would end at a point only differing with\n    its original capacity. Concert of action, by which man\u2019s power over\n    the material world is maintained, would not exceed, if it equaled,\n    that which is seen among the bees; and the material results of his\n    labors would not extend beyond securing the means of life and the\n    employment of the simplest modes of defence and attack.\n\n    The first men, therefore, are looked upon by the developmentalists\n    as extremely embryonic in all that characterizes humanity, and they\n    appeal to the facts of history in support of this view. If they do\n    not derive much assistance from written history, evidence is found\n    in the more enduring relics of human handiwork.\n\n    The opposing view is, that the races which present or have presented\n    this condition of inferiority or savagery have reached it by a\n    process of degradation from a higher state\u2014as some believe, through\n    moral delinquency. This position may be true in certain cases, which\n    represent perhaps a condition of senility, but in general we believe\n    that savagery was the condition of the first man, which has in some\n    races continued to the present day.\n\n                     _\u03b2. Evidence from Arch\u00e6ology._\n\n    As the object of the present essay is not to examine fully into the\n    evidences for the theories of evolution here stated, but rather to\n    give a sketch of such theories and their connection, a few facts\n    only will be noticed.\n\n    _Improvement in the use of Materials._ As is well known, the remains\n    of human handiwork of the earliest periods consist of nothing but\n    rude implements of stone and bone, useful only in procuring food and\n    preparing it for use. Even when enterprise extended beyond the\n    ordinary routine, it was restrained by the want of proper\n    instruments. Knives and other cutting implements of flint still\n    attest the skill of the early races of men from Java to the Cape of\n    Good Hope, from Egypt to Ireland, and through North and South\n    America. Hatchets, spear-heads and ornaments of serpentine, granite,\n    silex, clay slates, and all other suitable rock materials, are found\n    to have been used by the first men, to the exclusion of metals, in\n    most of the regions of the earth.\n\n    Later, the probably accidental discovery of the superiority of some\n    of the metals resulted in the substitution of them for stone as a\n    material for cutting implements. Copper\u2014the only metal which, while\n    malleable, is hard enough to bear an imperfect edge\u2014was used by\n    succeeding races in the Old World and the New. Implements of this\n    material are found scattered over extensive regions. So desirable,\n    however, did the hardening of the material appear for the\n    improvement of the cutting edge that combinations with other metals\n    were sought for and discovered. The alloy with tin, forming bronze\n    and brass, was discovered and used in Europe, while that with silver\n    appears to have been most readily produced in America, and was\n    consequently used by the Peruvians and other nations.\n\n    The discovery of the modes of reducing iron ores placed in the hands\n    of man the best material for bringing to a shape, convenient for his\n    needs the raw material of the world. All improvements in this\n    direction made since that time have been in the quality of iron\n    itself, and not through the introduction of any new metal.\n\n    The prevalent phenomena of any given period are those which give it\n    its character, and by which we distinguish it. But this fact does\n    not exclude the co\u00ebxistence of other phenomena belonging to prior or\n    subsequent stages. Thus, during the many stages of human progress\n    there have been men more or less in advance of the general body, and\n    their characteristics have given a peculiar stamp to the later and\n    higher condition of the whole. It furnishes no objection to this\n    view that we find, as might have been anticipated, the stone, bronze\n    and iron periods overlaping one another, or men of an inferior\n    culture supplanting in some cases a superior people. A case of this\n    kind is seen in North America, where the existing \u201cIndians,\u201d\n    stone-men, have succeeded the mound-builders, copper-men. The\n    successional relation of discoveries is all that it is necessary to\n    prove, and this seems to be established.\n\n    The period at which the use of metallic implements was introduced is\n    unknown, but Whitney says that the language of the Aryans, the\n    ancestors of all the modern Indo-Europeans, indicates an\n    acquaintance with such implements, though it is not certain whether\n    those of iron are to be included. The dispersion of the daughter\n    races, the Hindoos, the Pelasgi, Teutons, Celts, etc., could not, it\n    is thought, have taken place later than 3000 B. C.\u2014a date seven\n    hundred years prior, to that assigned by the old chronology to the\n    Deluge. Those races co\u00ebxisted with the Egyptian and Chinese nations,\n    already civilized, and as distinct from each other in feature as\n    they are now.\n\n    _Improvement in Architecture._ The earliest periods, then, were\n    characterized by the utmost simplicity of invention and\n    construction. Later, the efforts for defence from enemies and for\n    architectural display, which have always employed so much time and\n    power, began to be made. The megalithic period has left traces over\n    much of the earth. The great masses of stone piled on each other in\n    the simplest form in Southern India, and the circles of stones\n    planted on end in England at Stonehenge and Abury, and in Peru at\n    Sillustani, are relics of that period. More complex are the great\n    Himyaritic walls of Arabia, the works of the ancestors of the\n    Ph\u0153nicians in Asia Minor, and the titanic workmanship of the Pelasgi\n    in Greece and Italy. In the iron age we find granitic hills shaped\n    or excavated into temples; as, for example, everywhere in Southern\n    India. Near Madura the circumference of an acropolis-like hill is\n    cut into a series of statues in high relief, of sixty feet in\n    elevation. Easter Island, composed of two volcanic cones, one\n    thousand miles from the west coast of South America, in the bosom of\n    the Pacific, possesses several colossi cut from the intrusive\n    basalt, some in high relief on the face of the rock, others in\n    detached blocks removed by human art from their original positions\n    and brought nearer the sea-shore.\n\n    Finally, at a more advanced stage, the more ornate and complex\n    structures of Central America, of Cambodia, Nineveh and Egypt,\n    represent the period of greatest display of architectural\n    expenditure. The same amount of human force has perhaps never been\n    expended in this direction since, though higher conceptions of\n    beauty have been developed in architecture with increasing\n    intellectuality.\n\n    Man has passed through the block-and-brick building period of his\n    boyhood, and should rise to higher conceptions of what is the true\n    disposition of power for \u201chim who builds for aye,\u201d and learn that\n    \u201cspectacle\u201d is often the unwilling friend of progress.\n\n    No traces of metallic implements have ever been found in the\n    salt-mines of Armenia, the turquoise-quarries in Arabia, the cities\n    of Central America or the excavations for mica in North Carolina,\n    while the direct evidence points to the conclusion that in those\n    places flint was exclusively used.\n\n    The simplest occupations, as requiring the least exercise of mind,\n    are the pursuit of the chase and the tending of flocks and herds.\n    Accordingly, we find our first parents engaged in these occupations.\n    Cain, we are told, was, in addition, a tiller of the ground.\n    Agriculture in its simplest forms requires but little more\n    intelligence than the pursuits just mentioned, though no employment\n    is capable of higher development. If we look at the savage nations\n    at present occupying nearly half the land surface of the earth, we\n    shall find many examples of the former industrial condition of our\n    race preserved to the present day. Many of them had no knowledge of\n    the use of metals until they obtained it from civilized men who\n    visited them, while their pursuits were and are those of the chase,\n    tending domestic animals, and rudimental agriculture.\n\n                    \u03b3. The Development of Language.\n\n    In this department the fact of development from the simple to the\n    complex has been so satisfactorily demonstrated by philologists as\n    scarcely to require notice here. The course of that development has\n    been from monosyllabic to polysyllabic forms, and also in a process\n    of differentiation, as derivative races were broken off from the\n    original stock and scattered widely apart. The evidence is clear\n    that simple words for distinct objects formed the bases of the\n    primal languages, just as the ground, tree, sun and moon represent\n    the character of the first words the infant lisps. In this\n    department also the facts point to an infancy of the human race.\n\n                    \u03b4. Development of the Fine Arts.\n\n    If we look at representation by drawing or sculpture, we find that\n    the efforts of the earliest races of which we have any knowledge\n    were quite similar to those which the untaught hand of infancy\n    traces on its slate or the savage depicts on the rocky faces of\n    hills. The circle or triangle for the head and body, and straight\n    lines for the limbs, have been preserved as the first attempts of\n    the men of the stone period, as they are to this day the sole\n    representations of the human form which the North American Indian\n    places on his buffalo robe or mountain precipice. The stiff,\n    barely-outlined form of the deer, the turtle, etc., are literally\n    those of the infancy of civilized man.\n\n    The first attempts at sculpture were marred by the influence of\n    modism. Thus the idols of Coban and Palenque, with human faces of\n    some merit, are overloaded with absurd ornament, and deformed into\n    frightful asymmetry, in compliance with the demand of some imperious\n    mode. In later days we have the stiff, conventionalized figures of\n    the palaces of Nineveh and the temples of Egypt, where the\n    representation of form has somewhat improved, but is too often\n    distorted by false fashion or imitation of some unnatural standard,\n    real or artistic. This is distinguished as the day of archaic\n    sculpture, which disappeared with the Etruscan nation. So the\n    drawings of the child, when he abandons the simple lines, are stiff\n    and awkward, and but a stage nearer true representation; and how\n    often does he repeat some peculiarity or absurdity of his own! So\n    much easier is it to copy than to conceive.\n\n    The introduction of the action and pose of life into sculpture was\n    not known before the early days of Greece, and it was there that the\n    art was brought to perfection. When art rose from its medi\u00e6val\n    slumber, much the same succession of development may be discovered.\n    First, the stiff figures, with straightened limbs and cylindric\n    drapery, found in the old Northern churches\u2014then the forms of life\n    that now adorn the porticoes and palaces of the cities of Germany.\n\n            \u03b5. Rationale of the Development of Intelligence.\n\n    The history of material development shows that the transition from\n    stage to stage of development, experienced by the most perfect forms\n    of animals and plants in their growth from the primordial cell, is\n    similar to the succession of created beings which the geological\n    epochs produced. It also shows that the slow assumption of main\n    characters in the line of succession in early geological periods\n    produced the condition of inferiority, while an increased rapidity\n    of growth in later days has resulted in an attainment of\n    superiority. It is not to be supposed that in \u201cacceleration\u201d the\n    period of growth is shortened: on the contrary, it continues the\n    same. Of two beings whose characters are assumed at the same rate of\n    succession, that with the quickest or shortest growth is necessarily\n    inferior. \u201cAcceleration\u201d means a gradual increase of the rate of\n    assumption of successive characters in the same period of time. A\n    fixed rate of assumption of characters, with gradual increase in the\n    length of the period of growth, would produce the same result\u2014viz.,\n    a longer developmental scale and the attainment of an advanced\n    position. The first is in part the relation of sexes of a species;\n    the last of genera, and of other types of creation. If from an\n    observed relation of many facts we derive a law, we are permitted,\n    when we see in another class of facts similar relations, to suspect\n    that a similar law has operated, differing only in its objects. We\n    find a marked resemblance between the facts of structural progress\n    in matter and the phenomena of intellectual and spiritual progress.\n\n    If the facts entering into the categories enumerated in the\n    preceding section bear us out, we conclude that in the beginning of\n    human history the progress of the individual man was very slow, and\n    that but little was attained to; that through the profitable\n    direction of human energy, means were discovered from time to time\n    by which the process of individual development in all metaphysical\n    qualities has been accelerated; and that up to the present time the\n    consequent advance of the whole race has been at an increasing rate\n    of progress, This is in accordance with the general principle, that\n    high development in intellectual things is accomplished by rapidity\n    in traversing the preliminary stages of inferiority common to all,\n    while low development signifies sluggishness in that progress, and a\n    corresponding retention of inferiority.\n\n    How much meaning may we not see, from this stand-point, in the\n    history of the intelligence of our little ones! First they crawl,\n    they walk on all fours: when they first assume the erect position\n    they are generally speechless, and utter only inarticulate sounds.\n    When they run about, stones and dirt, the objects that first meet\n    the eye, are the delight of their awakening powers, but these are\n    all cast aside when the boy obtains his first jackknife. Soon,\n    however, reading and writing open a new world to him; and finally as\n    a mature man he seizes the forces of nature, and steam and\n    electricity do his bidding in the active pursuit of power for still\n    better and higher ends.\n\n    So with the history of the species: first the quadrumane\u2014then the\n    speaking man, whose humble industry was, however, confined to the\n    objects that came first to hand, this being the \u201cstone age\u201d of\n    pre-historic time. When the use of metals was discovered, the range\n    of industries expanded wonderfully, and the \u201ciron age\u201d saw many\n    striking efforts of human power. With the introduction of letters it\n    became possible to record events and experiences, and the spread of\n    knowledge was thereby greatly increased, and the delays and mistakes\n    of ignorance correspondingly diminished in the fields of the world\u2019s\n    activity.\n\n    From the first we see in history a slow advance as knowledge gained\n    by the accumulation of tradition and by improvements in habit based\n    on experience; but how slow was this advance while the use of the\n    metals was still unknown! The iron age brought with it not only new\n    conveniences, but increased means of future progress; and here we\n    have an acceleration in the rate of advance. With the introduction\n    of letters this rate was increased many fold, and in the application\n    of steam we have a change equal in utility to any that has preceded\n    it, and adding more than any to the possibilities of future advance\n    in many directions. By its power, knowledge and means of happiness\n    were to be distributed among the many.\n\n    The uses to which human intelligence has successively applied the\n    materials furnished by nature have been\u2014First, subsistence and\n    defence: second, the accumulation of power in the shape of a\n    representative of that labor which the use of matter involves; in\n    other words, the accumulation of wealth. The possession of this\n    power involves new possibilities, for opportunity is offered for the\n    special pursuits of knowledge and the assistance of the weak or\n    undeveloped part of mankind in its struggles.\n\n    Thus, while the first men possessed the power of speech, and could\n    advance a little in knowledge through the accumulation of the\n    experiences of their predecessors, they possessed no means of\n    accumulating the power of labor, no control over the activity of\n    numbers\u2014in other words, no wealth.\n\n    But the accumulation of knowledge finally brought this advance\n    about. The extraction and utilization of the metals, especially\n    iron, formed the most important step, since labor was thus\n    facilitated and its productiveness increased in an incalculable\n    degree. We have little evidence of the existence of a medium of\n    exchange during the first or stone period, and no doubt barter was\n    the only form of trade. Before the use of metals, shells and other\n    objects were used: remains of money of baked clay have been found in\n    Mexico. Finally, though in still ancient times, the possession of\n    wealth in money gradually became possible and more common, and from\n    that day to this avenues for reaching this stage in social progress\n    has ever been opening.\n\n    But wealth merely indicates a stage of progress, since it is but a\n    comparative term. All men could not become rich, for in that case\n    all would be equally poor. But labor has a still higher goal; for,\n    thirdly, as capital, it constructs and employs machinery, which does\n    the work of many hands, and thus cheapens products, which is\n    equivalent in effect to an accumulation of wealth to the consumer.\n    And this increase of power may be used for the intellectual and\n    spiritual advance of men, or otherwise, at the will of the men thus\n    favored. Machinery places man in the position of a creator,\n    operating on Nature through an increased number of \u201csecondary\n    causes.\u201d\n\n    Development of intelligence is seen, then, in the following\n    directions: First, in the knowledge of facts, including science;\n    second, in language; third, in the apprehension of beauty; and, as\n    consequences of the first of these, the accumulation of power by\n    development\u2014First, of means of subsistence; and second, of\n    mechanical invention.\n\n    Thus we have two terms to start with in estimating the beginning of\n    human development in knowledge and power: First, the primary\n    capacities of the human mind itself; second, a material world, whose\n    infinitely varied components are so arranged as to yield results to\n    the energies of that mind. For example, the transition points of\n    vaporization and liquefaction are so placed as to be within the\n    reach of man\u2019s agents; their weights are so fixed as to accord with\n    the muscular or other forces which he is able to exert; and other\n    living organizations are subject to his convenience and rule, and\n    not, as in previous geological periods, entirely beyond his control.\n    These two terms being given, it is maintained that the present\n    situation of the most civilized men has been attained through the\n    operation of a law of mutual action and reaction\u2014a law whose\n    results, seen at the present time, have depended on the acceleration\n    or retardation of its rate of action; which rate has been regulated,\n    according to the degree in which a third great term, viz., the law\n    of moral or (what is the same thing) true religious development has\n    been combined in the plan. What it is necessary to establish in\n    order to prove the above hypothesis is\u2014\n\n    I. That in each of the particulars above enumerated the development\n    of the human species is similar to that of the individual from\n    infancy to maturity.\n\n    II. That from a condition of subserviency to the laws of matter,\n    man\u2019s intelligence enables him, by an accumulation of power, to\n    become in a sense independent of those laws, and to increase greatly\n    the rate of intellectual and spiritual progress.\n\n    III. That failure to accomplish a moral or spiritual development\n    will again reduce him to a subserviency to the laws of matter.\n\n    This brings us to the subject of moral development. And here I may\n    be allowed to suggest that the weight of the evidence is opposed to\n    the philosophy, \u201cfalsely so called,\u201d of necessitarianism, which\n    asserts that the first two terms alone were sufficient to work out\n    man\u2019s salvation in this world and the next; and, on the other hand,\n    to that anti-philosophy which asserts that all things in the\n    progress of the human race, social and civil, are regulated by\n    immediate Divine interposition instead of through instrumentalities.\n    Hence the subject divides itself at once into two great\n    departments\u2014viz., that of the development of mind or intelligence,\n    and that of the development of morality.\n\n    That these laws are distinct there can be no doubt, since in the\n    individual man one of them may produce results without the aid of\n    the other. Yet it can be shown that each is the most invaluable aid\n    and stimulant to the other, and most favorable to the rapid advance\n    of the mind in either direction.\n\n\n                  III. SPIRITUAL OR MORAL DEVELOPMENT.\n\n    In examining this subject, we first inquire (Sect. _\u03b1_) whether\n    there is any connection between physical and moral or religious\n    development; then (_\u03b2_), what indications of moral development may\n    be derived from history. Finally (_\u03b3_), a correlation of the results\n    of these inquiries, with the nature of the religious development in\n    the individual, is attempted. Of course in so stupendous an inquiry\n    but a few leading points can be presented here.\n\n    If it be true that the period of human existence on the earth has\n    seen a gradually increasing predominance of higher motives over\n    lower ones among the mass of mankind, and if any parts of our\n    metaphysical being have been derived by inheritance from pre\u00ebxistent\n    beings, we are incited to the inquiry whether any of the moral\n    qualities are included among the latter; and whether there be any\n    resemblance between moral and intellectual development.\n\n    Thus, if there have been a physical derivation from a pre\u00ebxistent\n    genus, and an embryonic condition of those physical characters which\n    distinguish Homo\u2014if there has been also an embryonic or infantile\n    stage in intellectual qualities\u2014we are led to inquire whether the\n    development of the individual in moral nature will furnish us with a\n    standard of estimation of the successive conditions or present\n    relations of the human species in this aspect also.\n\n              _a. Relations of Physical and Moral Nature._\n\n    Although men are much alike in the deeper qualities of their nature,\n    there is a range of variation which is best understood by a\n    consideration of the extremes of such variation, as seen in men of\n    different latitudes, and women and children.\n\n    (_a._) _In Children._ Youth is distinguished by a peculiarity, which\n    no doubt depends upon an immature condition of the nervous center\n    concerned, which might be called _nervous impressibility_. It is\n    exhibited in a greater tendency to tearfulness, in timidity, less\n    mental endurance, a greater facility in acquiring knowledge, and\n    more ready susceptibility to the influence of sights, sounds and\n    sensations. In both sexes the emotional nature predominates over the\n    intelligence and judgment. In those years the _character_ is said to\n    be in embryo, and theologians in using the phrase, \u201creaching years\n    of religious understanding,\u201d mean that in early years the religious\n    _capacities_ undergo development coincidentally with those of the\n    body.\n\n    (_b._) _In Women._ If we examine the metaphysical characteristics of\n    women, we observe two classes of traits\u2014namely, those which are also\n    found in men, and those which are absent or but weakly developed in\n    men. Those of the first class are very similar in essential nature\n    to those which men exhibit at an early stage of development. This\n    may be in some way related to the fact that physical maturity occurs\n    earlier in women.\n\n    The gentler sex is characterized by a greater impressibility, often\n    seen in the influence exercised by a stronger character, as well as\n    by music, color or spectacle generally; warmth of emotion,\n    submission to its influence rather than that of logic; timidity and\n    irregularity of action in the outer world. All these qualities\n    belong to the male sex, as a general rule, at some period of life,\n    though different individuals lose them at very various periods.\n    Ruggedness and sternness may rarely be developed in infancy, yet at\n    some still prior time they certainly do not exist in any.\n\n    Probably most men can recollect some early period of their lives\n    when the emotional nature predominated\u2014a time when emotion at the\n    sight of suffering was more easily stirred than in maturer years. I\n    do not now allude to the benevolence inspired, kept alive or\n    developed by the influence of the Christian religion on the heart,\n    but rather to that which belongs to the natural man. Perhaps all men\n    can recall a period of youth when they were hero-worshipers\u2014when\n    they felt the need of a stronger arm, and loved to look up to the\n    powerful friend who could sympathize with and aid them. This is the\n    \u201cwoman stage\u201d of character: in a large number of cases it is early\n    passed; in some it lasts longer; while in a very few men it persists\n    through life. Severe discipline and labor are unfavorable to its\n    persistence. Luxury preserves its bad qualities without its good,\n    while Christianity preserves its good elements without its bad.\n\n    It is not designed to say that woman in her emotional nature does\n    not differ from the undeveloped man. On the contrary, though she\n    does not differ in kind, she differs greatly in degree, for her\n    qualities grow with her growth, and exceed in _power_ many fold\n    those exhibited by her companion at the original point of departure.\n    Hence, since it might be said that man is the undeveloped woman, a\n    word of explanation will be useful. Embryonic types abound in the\n    fields of nature, but they are not therefore immature in the usual\n    sense. Maintaining the lower essential quality, they yet exhibit the\n    usual results of growth in individual characters; that is, increase\n    of strength, powers of support and protection, size and beauty. In\n    order to maintain that the masculine character coincides with that\n    of the undeveloped woman, it would be necessary to show that the\n    latter during her infancy possesses the male characters\n    predominating\u2014that is, unimpressibility, judgment, physical courage,\n    and the like.\n\n    If we look at the second class of female characters\u2014namely, those\n    which are imperfectly developed or absent in men, and in respect to\n    which man may be called undeveloped woman\u2014we note three prominent\n    points: facility in language, tact or finesse, and the love of\n    children. The first two appear to me to be altogether developed\n    results of \u201cimpressibility,\u201d already considered as an indication of\n    immaturity. Imagination is also a quality of impressibility, and,\n    associated with finesse, is apt to degenerate into duplicity and\n    untruthfulness.\n\n    The third quality is different. It generally appears at a very early\n    period of life. Who does not know how soon the little girl selects\n    the doll, and the boy the toy-horse or machine? Here man truly never\n    gets beyond undeveloped woman. Nevertheless, \u201cimpressibility\u201d seems\n    to have a great deal to do with this quality also.\n\n    Thus the metaphysical relation of the sexes would appear to be one\n    of _inexact parallelism_, as defined in Sect. I. That the physical\n    relation is a remote one of the same kind, several characters seem\n    to point out. The case of the vocal organs will suffice. Their\n    structure is identical in both sexes in early youth, and both\n    produce nearly similar sounds. They remain in this condition in the\n    woman, while they undergo a metamorphosis and change both in\n    structure and vocal power in the man. In the same way, in many of\n    the lower creation, the females possess a majority of embryonic\n    features, though not invariably. A common example is to be found in\n    the plumage of birds, where the females and young males are often\n    undistinguishable.[48] But there are few points in the physical\n    structure of man also in which the male condition is the immature\n    one. In regard to structure, the point at which the relation between\n    the sexes is that of _exact parallelism_, or where the mature\n    condition of the one sex accords with the undeveloped condition of\n    the other, is when reproduction is no longer accomplished by budding\n    or gemmation, but requires distinct organs. Metaphysically, this\n    relation is to be found where distinct individuality of the sexes\n    first appears; that is, where we pass from the hermaphrodite to the\n    bisexual condition.\n\nFootnote 48:\n\n      Meehan states that the upper limbs and strong laterals in conifer\u00e6\n      and other trees produce female flowers and cones, and the lower\n      and more interior branches the male flowers. What he points out is\n      in harmony with the position here maintained\u2014namely, that the\n      female characters include more of those which are embryonic in the\n      males, than the male characters include of those which are\n      embryonic in the female: the female flowers are the product of the\n      younger and more growing portions of the tree\u2014that is, those last\n      produced (the upper limbs and new branches)\u2014while the male flowers\n      are produced by the older or more mature portions\u2014that is, lower\n      limbs or more axial regions.\n\n      Meehan\u2019s observations coincide with those of Thury and others on\n      the origin of sexes in animals and plants, which it appears to\n      admit of a similar explanation.\n\n    But let us put the whole interpretation on this partial\n    undevelopment of woman.\n\n    The types or conditions of organic life which have been the most\n    prominent in the world\u2019s history\u2014the Ganoids of the first, the\n    Dinosaurs of the second, and the Mammoths of the third period\u2014have\n    generally died with their day. The line of succession has not been\n    from them. The law of anatomy and paleontology is, that we must seek\n    the point of departure of the type which is to predominate in the\n    future, at lower stages on the line, in less decided forms, or in\n    what, in scientific parlance, are called generalized types. In the\n    same way, though the adults of the tailless apes are in a physical\n    sense more highly developed than their young, yet the latter far\n    more closely resemble the human species in their large facial angle\n    and shortened jaws.\n\n    How much significance, then, is added to the law uttered by\n    Christ!\u2014\u201cExcept ye become as little children, ye cannot enter the\n    kingdom of heaven.\u201d Submission of will, loving trust, confiding\n    faith\u2014these belong to the child: how strange they appear to the\n    executing, commanding, reasoning man! Are they so strange to the\n    woman? We all know the answer. Woman is nearer to the point of\n    departure of that development which outlives time and peoples\n    heaven; and if man would find it, he must retrace his steps, regain\n    something he lost in youth, and join to the powers and energies of\n    his character the submission, love and faith which the new birth\n    alone can give.\n\n    Thus the summing up of the metaphysical qualities of woman would be\n    thus expressed: In the emotional world, man\u2019s superior; in the moral\n    world, his equal; in the laboring world, his inferior.\n\n    There are, however, vast differences in women in respect to the\n    number of masculine traits they may have assumed before being\n    determined into their own special development. Woman also, under the\n    influence of necessity, in later years of life, may add more or less\n    to those qualities in her which are fully developed in the man.\n\n    The relation of these facts to the principles stated as the two\n    opposing laws of development is, it appears to me, to be explained\n    thus: First, that woman\u2019s most inherent peculiarities are _not_ the\n    result of the external circumstances with which she has been placed\n    in contact, as the _conflict theory_ would indicate. Such\n    circumstances are said to be her involuntary subserviency to the\n    physically more powerful man, and the effect of a compulsory mode of\n    life in preventing her from attaining a position of equality in the\n    activities of the world. Second, that they _are_ the result of the\n    different distributions of qualities as already indicated by the\n    _harmonic theory_ of development; that is, of the unequal possession\n    of features which belong to different periods in the developmental\n    succession of the highest. And here it might be further shown that\n    this relation involves no disadvantage to either sex, but that the\n    principle of compensation holds in moral organization and in social\n    order, as elsewhere. There is then another beautiful harmony which\n    will ever remain, let the development of each sex be extended as far\n    as it may.\n\n    (_c._) _In Men._ If we look at the male sex, we shall find various\n    exceptional approximations to the female in mental constitution.\n    Further, there can be little doubt that in the Indo-European race\n    maturity in some respects appears earlier in tropical than in\n    northern regions; and though subject to many exceptions, this is\n    sufficiently general to be looked upon as a rule. Accordingly, we\n    find in that race\u2014at least in the warmer regions of Europe and\n    America\u2014a larger proportion of certain qualities which are more\n    universal in women; as greater activity of the emotional nature when\n    compared with the judgment; an impressibility of the nervous center,\n    which, _c\u00e6teris paribus_, appreciates quickly the harmonies of\n    sound, form and color; answers most quickly to the friendly greeting\n    or the hostile menace; is more careless of consequences in the\n    material expression of generosity or hatred, and more indifferent to\n    truth under the influence of personal relations. The movements of\n    the body and expressions of the countenance answer to the\n    temperament. More of grace and elegance in the bearing mark the\n    Greek, the Italian and the Creole, than the German, the Englishman\n    or the Green Mountain man. More of vivacity and fire, for better or\n    for worse, are displayed in the countenance.\n\n    Perhaps the more northern type left all that behind in its youth.\n    The rugged, angular character which appreciates force better than\n    harmony, the strong intellect which delights in forethought and\n    calculation, the less impressibility, reaching stolidity in the\n    uneducated, are its well-known traits. If in such a character\n    generosity is less prompt, and there is but little chivalry, there\n    is persistency and unwavering fidelity, not readily interrupted by\n    the lightning of passion or the dark surmises of an active\n    imagination.\n\n    All these peculiarities appear to result, _first_, from different\n    degrees of quickness and depth in appreciating impressions from\n    without; and, _second_, from differing degrees of attention to the\n    intelligent judgment in consequent action. (I leave conscience out,\n    as not belonging to the category of inherited qualities.)\n\n    The first is the basis of an emotional nature, and the predominance\n    of the second is the usual indication of maturity. That the first is\n    largely dependent on an impressible condition of the nervous system\n    can be asserted by those who reduce their nervous centers to a\n    sensitive condition by a rapid consumption of the nutritive\n    materials necessary to the production of thought-force, and perhaps\n    of brain-tissue itself, induced by close and prolonged mental labor.\n    The condition of over-work, though but an imitation of immaturity,\n    without its joy-giving nutrition, is nevertheless very instructive.\n    The sensitiveness, both physically, emotionally and morally, is\n    often remarkable, and a weakening of the understanding is often\n    coincident with it.\n\n    It is necessary here to introduce a caution, that the meaning of the\n    words high and low be not misunderstood. Great impressibility is an\n    essential constituent of many of the highest forms of genius, and\n    the combination of this quality with strong reflective intelligence,\n    constitutes the most complete and efficient type of mind\u2014therefore\n    the highest in the common sense. It is not, however, the highest\u2014or\n    extremest\u2014in an evolutional sense, it is not masculine, but\n    hermaphrodite; in other words, its _kinetic_ force exceeds its\n    _bathmic_.[49] It is therefore certain that a partial diminution of\n    bathmic vigor is an advantage to some kinds of intellect.\n\nFootnote 49:\n\n      _Bathmic force_ is analogous to the _potential_ force of chemists,\n      but is no doubt entirely different in its nature. It is converted\n      into active energy or _kinetic_ force only during the years of\n      growth: it is in large amount in _acceleration_, in small amount\n      in _retardation_.\n\n    The above observations have been confined to the Indo-European race.\n    It may be objected to the theory that savagery means immaturity in\n    the senses above described, as dependent largely on\n    \u201cimpressibility,\u201d while savages in general display the least\n    \u201cimpressibility,\u201d as that word is generally understood. This cannot\n    be asserted of the Africans, who, so far as we know them, possess\n    this peculiarity in a high degree. Moreover, it must be remembered\n    that the state of indifference which precedes that of impressibility\n    in the individual may characterize many savages; while their varied\n    peculiarities may be largely accounted for by recollecting that many\n    combinations of different species of emotions and kinds of\n    intelligence go to make up the complete result in each case.\n\n    (_d._) _Conclusions._ Three types of religion may be selected from\n    the developmental conditions of man: first, an absence of\n    sensibility (early infancy); second, an emotional stage more\n    productive of faith than of works; thirdly, an intellectual type,\n    more favorable to works than to faith. Though in regard to\n    responsibility these states may be equal, there is absolutely no\n    gain to laboring humanity from the first type, and a serious loss in\n    actual results from the second, taken alone, as compared with the\n    third.\n\n    These, then, are the _physical vehicles of religion_\u2014the \u201c_earthen\n    vessels_\u201d of Paul\u2014which give character and tone to the deeper\n    spiritual life, as the color of the transparent vessel is\n    communicated to the light which radiates from within.\n\n    But if evolution has taken place, there is evidently a provision for\n    the progress from the lower to the higher states, either in the\n    education of circumstances (\u201cconflict,\u201d) or in the power of an\n    interior spiritual influence \u201charmony,\u201d) or both.\n\n                  _\u03b2. Evidence Derived from History._\n\n    We trace the development of Morality in\u2014First, the family or social\n    order; second, the civil order, or government.\n\n    Whatever may have been the extent of moral ignorance before the\n    Deluge, it does not appear that the earth was yet prepared for the\n    permanent habitation of the human race. All nations preserve\n    traditions of the drowning of the early peoples by floods, such as\n    have occurred frequently during geologic time. At the close of each\n    period of dry land, a period of submergence has set in, and the\n    depression of the level of the earth, and consequent overflow by the\n    sea, has caused the death and subsequent preservation of the remains\n    of the fauna and flora living upon it, while the elevation of the\n    same has produced that interruption in the process of deposit in the\n    same region which marks the intervals between geologic periods.\n    Change in these respects do not occur to any very material extent at\n    the present time in the regions inhabited by the most highly\n    developed portions of the human race; and as the last which occurred\n    seems to have been expressly designed for the preparation of the\n    earth\u2019s surface for the occupation of organized human society, it\n    may be doubted whether many such changes are to be looked for in the\n    future. The last great flooding was that which stratified the drift\n    materials of the north, and carried the finer portions far over the\n    south, determining the minor topography of the surface and supplying\n    it with soils.\n\n    The existence of floods which drowned many races of men may be\n    considered as established. The men destroyed by the one recorded by\n    Moses are described by him as exceedingly wicked, so that \u201cthe earth\n    was filled with violence.\u201d In his eyes the Flood was designed for\n    their extermination.\n\n    That their condition was evil must be fully believed if they were\n    condemned by the executive of the Jewish law. This law, it will be\n    remembered, permitted polygamy, slavery, revenge, aggressive war.\n    The Jews were expected to rob their neighbors the Egyptians of\n    jewels, and they were allowed \u201can eye for an eye and a tooth for a\n    tooth.\u201d They were expected to butcher other nations, with their\n    women and children, their flocks and their herds. If we look at the\n    lives of men recorded in the Old Testament as examples of\n    distinguished excellence, we find that their standard, however\n    superior to that of the people around them, would ill accord with\n    the morality of the present day. They were all polygamists,\n    slaveholders and warriors. Abraham treated Hagar and Ishmael with\n    inhumanity. Jacob, with his mother\u2019s aid, deceived Isaac, and\n    received thereby a blessing which extended to the whole Jewish\n    nation. David, a man whom Paul tells us the Lord found to be after\n    his own heart, slew the messenger who brought tidings of the death\n    of Saul, and committed other acts which would stain the reputation\n    of a Christian beyond redemption. It is scarcely necessary to turn\n    to other nations if this be true of the chosen men of a chosen\n    people. History indeed presents us with no people prior to, or\n    contemporary with, the Jews who were not morally their inferiors.\n\n    If we turn to more modern periods, an examination of the morality of\n    Greece and Rome reveals a curious intermixture of lower and higher\n    moral conditions. While each of these nations produced excellent\n    moralists, the influence of their teachings was not sufficient to\n    elevate the masses above what would now be regarded as a very low\n    standard. The popularity of those scenes of cruelty, the\n    gladiatorial shows and the combats with wild beasts, sufficiently\n    attests this. The Roman virtue of patriotism, while productive of\n    many noble deeds, is in itself far from being a disinterested one,\n    but partakes rather of the nature of partisanship and selfishness.\n    If the Greeks were superior to the Romans in humanity, they were\n    apparently their inferiors in the social virtues, and were much\n    below the standard of Christian nations in both respects.\n\n    Ancient history points to a state of chronic war, in which the\n    social relations were in confusion, and the development of the\n    useful arts was almost impossible. Savage races, which continue to\n    this day in a similar moral condition, are, we may easily believe,\n    most unhappy. They are generally divided into tribes, which are\n    mutually hostile, or friendly only with the view of injuring some\n    other tribe. Might is their law, and robbery, rapine and murder\n    express their mutual relations. This is the history of the lowest\n    grade of barbarism, and the history of primeval man so far as it has\n    come down to us in sacred and profane records. Man as a species\n    first appears in history as a sinful being. Then a race maintaining\n    a contest with the prevailing corruption and exhibiting a higher\n    moral ideal is presented to us in Jewish history. Finally, early\n    Christian society exhibits a greatly superior condition of things.\n    In it polygamy scarcely existed, and slavery and war were condemned.\n    But progress did not end here, for our Lord said, \u201cI have yet many\n    things to say unto you, _but ye cannot bear them now_. Howbeit, when\n    He, the spirit of truth, is come, He will guide you into all truth.\u201d\n\n    The progress revealed to us by history is truly great, and if a\n    similar difference existed between the first of the human species\n    and the first of whose condition we have information, we can\n    conceive how low the origin must have been. History begins with a\n    considerable progress in civilization, and from this we must infer a\n    long preceding period of human existence, such as a gradual\n    evolution would require.\n\n                   \u03b3. Rationale of Moral Development.\n\n    I. _Of the Species._ Let us now look at the moral condition of the\n    infant man of the present time. We know his small accountability,\n    his trust, his innocence. We know that he is free from the law that\n    when he \u201cwould do good, evil is present with him,\u201d for good and evil\n    are alike unknown. We know that until growth has progressed to a\n    certain degree he fully deserves the praise pronounced by Our\n    Saviour, that \u201cof such is the kingdom of heaven.\u201d Growth, however,\n    generally sees a change. We know that the buddings of evil appear\n    but too soon: the lapse of a few months sees exhibitions of anger,\n    disobedience, malice, falsehood, and their attendants\u2014the fruit of a\n    corruption within not manifested before.\n\n    In early youth it may be said that moral susceptibility is often in\n    inverse ratio to physical vigor. But with growth the more physically\n    vigorous are often sooner taught the lessons of life, for their\n    energy brings them into earlier conflict with the antagonisms and\n    contradictions of the world. Here is a beautiful example of the\n    benevolent principle of compensation.\n\n    1. _Innocence and the Fall._ If physical evolution be a reality, we\n    have reason to believe that the infantile stage of human morals, as\n    well as of human intellect, was much prolonged in the history of our\n    first parents. This constitutes the period of human purity, when we\n    are told by Moses that the first pair dwelt in Eden. But the growth\n    to maturity saw the development of all the qualities inherited from\n    the irresponsible denizen of the forest. Man inherits from his\n    predecessors in the creation the buddings of reason: he inherits\n    passions, propensities and appetites. His corruption is that of his\n    animal progenitors, and his sin is the low and bestial instinct of\n    the brute creation. Thus only is the origin of sin made clear\u2014a\n    problem which the pride of man would have explained in any other way\n    had it been possible.\n\n    But how startling the exhibition of evil by this new being as\n    compared with the scenes of the countless ages already past! Then\n    the right of the strongest was God\u2019s law, and rapine and destruction\n    were the history of life. But into man had been \u201cbreathed the breath\n    of life,\u201d and he had \u201cbecome a living soul.\u201d The law of right, the\n    Divine Spirit, was planted within him, and the laws of the beast\n    were in antagonism to that law. The natural development of his\n    inherited qualities necessarily brought him into collision with that\n    higher standard planted within him, and that war was commenced which\n    shall never cease \u201ctill He hath put all things under His feet.\u201d The\n    first act of man\u2019s disobedience constituted the Fall, and with it\n    would come the first _intellectual_ \u201cknowledge of good and of\n    evil\u201d\u2014an apprehension up to that time derived exclusively from the\n    divinity within, or conscience.[50]\n\nFootnote 50:\n\n      In our present translation of Genesis, the Fall is ascribed to the\n      influence of Satan assuming the form of the serpent, and this\n      animal was cursed in consequence, and compelled to assume a prone\n      position. This rendering may well be revised, since serpents,\n      prone like others, existed in both America and Europe during the\n      Eocene epoch, five times as great a period before Adam as has\n      elapsed since his day. Clark states, with great probability, that\n      \u201cserpent\u201d should be translated monkey or ape\u2014a conclusion, it will\n      be observed, exactly coinciding with our inductions on the basis\n      of evolution. The instigation to evil by an ape merely states\n      inheritance in another form. His curse, then, refers to the\n      retention of the horizontal position by all other quadrumana, as\n      we find it at the present day.\n\n    2. _Free Agency._ Heretofore development had been that of physical\n    types, but the Lord had rested on the seventh day, for man closed\n    the line of the physical creation. Now a new development was to\n    begin\u2014the development of mind, of morality and of grace.\n\n    On the previous days of Creation all had progressed in accordance\n    with inevitable law apart from its objects. Now two lines of\n    development were at the disposal of this being, between which his\n    _free will_ was to choose. Did he choose the courses dictated by the\n    spirit of the brute, he was to be subject to the old law of the\n    brute creation\u2014the right of the strongest and spiritual death. Did\n    he choose the guidance of the Divine Guest in his heart, he became\n    subject to the laws which are to guide\u2014I. the human species to an\n    ultimate perfection, so far as consistent with this world; and II.\n    the individual man to a higher life, where a new existence awaits\n    him as a spiritual being, freed from the laws of terrestrial matter.\n\n    The charge brought against the theory of development, that it\n    implies a necessary progress of man to all perfection without his\n    co\u00f6peration\u2014or _necessitarianism_, as it is called\u2014is unfounded.\n\n    The free will of man remains the source alike of his progress and\n    his relapse. But the choice once made, the laws of spiritual\n    development are apparently as inevitable as those of matter. Thus\n    men whose religious capacities are increased by attention to the\n    Divine Monitor within are in the advance of progress\u2014progress\n    coinciding with that which in material things is called the\n    _harmonic_. On the other hand, those whose motives are of the lower\n    origin fall under the working of the law of _conflict_.\n\n    The lesson derivable from the preceding considerations would seem to\n    be \u201cnecessitarian\u201d as respects the whole human race, considered by\n    itself; and I believe it is to be truly so interpreted. That is, the\n    Creator of all things has set agencies at work which will slowly\n    develop a perfect humanity out of His lower creation, and nothing\n    can thwart the process or alter the result. \u201cMy word shall not\n    return unto Me void, but it shall accomplish that which I please,\n    and it shall prosper in the thing whereto I sent it.\u201d This is our\n    great encouragement, our noblest hope\u2014second only to that which\n    looks to a blessed inheritance in another world. It is this thought\n    that should inspire the farmer, who as he toils wonders, \u201cWhy all\n    this labor? The Good Father could have made me like the lilies, who,\n    though they toil not, neither spin, are yet clothed in glory; and\n    why should I, a nobler being, be subject to the dust and the sweat\n    of labor?\u201d This thought should enlighten every artisan of the\n    thousands that people the factories and guide their whirling\n    machinery in our modern cities. Every revolution of a wheel is\n    moving the car of progress, and the timed stroke of the crank and\n    the rhythmic throw of the shuttle are but the music the spheres have\n    sung since time began. A new significance then appears in the prayer\n    of David: \u201cLet the beauty of the Lord our God be upon us, and\n    establish Thou the work of our hands upon us: the work of our hands,\n    O Lord, establish Thou it.\u201d But beware of the catastrophe, for \u201cHe\n    will sit as a refiner:\u201d \u201cthe wheat shall be gathered into barns, but\n    the chaff shall be burned with unquenchable fire.\u201d If this be true,\n    let us look for\u2014\n\n    3. _The Extinction of Evil._ How is necessitarianism to be\n    reconciled with free will? It appears to me, thus: When a being\n    whose safety depends on the perfection of a system of laws abandons\n    the system by which he lives, he becomes subject to that lower grade\n    of laws which govern lower intelligences. Man, falling from the laws\n    of right, comes under the dominion of the laws of brute force; as\n    said our Saviour: \u201cSalt is good, but if the salt have lost his\n    savor, it is thenceforth good for nothing but to be cast forth and\n    trodden under foot of men.\u201d\n\n    Evil, being unsatisfying to the human heart, is in its nature ever\n    progressive, whether in the individual or the nation; and in\n    estimating the practical results to man of the actions prompted by\n    the lower portion of our nature, it is only necessary to carry out\n    to its full development each of those animal qualities which may in\n    certain states of society be restrained by the social system. In\n    human history those qualities have repeatedly had this development,\n    and the battle of progress is fought to decide whether they shall\n    overthrow the system that restrains them, or be overthrown by it.\n\n    Entire obedience to the lower instincts of our nature ensures\n    destruction to the weaker, and generally to the stronger also. A\n    most marked case of this kind is seen where the developed vices of\n    civilization are introduced among a savage people\u2014as, for example,\n    the North American Indians. These seem in consequence to be\n    hastening to extinction.\n\n    But a system or a circuit of existence has been allotted to the\n    civil associations of the animal species man, independently of his\n    moral development. It may be briefly stated thus: Races begin as\n    poor offshoots or emigrants from a parent stock. The law of labor\n    develops their powers, and increases their wealth and numbers. These\n    will be diminished by their various vices; but on the whole, in\n    proportion as the intellectual and economical elements prevail,\n    wealth will increase; that is, they accumulate power. When this has\n    been accomplished, and before activity has slackened its speed, the\n    nation has reached the culminating point, and then it enters upon\n    the period of decline. The restraints imposed by economy and active\n    occupation being removed, the beastly traits find in accumulated\n    power only increased means of gratification, and industry and\n    prosperity sink together. Power is squandered, little is\n    accumulated, and the nation goes down to its extinction amid scenes\n    of internal strife and vice. Its cycle is soon fulfilled, and other\n    nations, fresh from scenes of labor, assault it, absorb its\n    fragments, and it dies. This has been the world\u2019s history, and it\n    remains to be seen whether the virtues of the nations now existing\n    will be sufficient to save them from a like fate.\n\n    Thus the history of the animal man in nations is wonderfully like\n    that of the type or families of the animal and vegetable kingdoms\n    during geologic ages. They rise, they increase and reach a period of\n    multiplication and power. The force allotted to them becoming\n    exhausted, they diminish and sink and die.\n\n    II. _Of the Individual._ In discussing physical development, we are\n    as yet compelled to restrict ourselves to the evidence of its\n    existence and some laws observed in the operation of its causative\n    force. What that force is, or what are its primary laws, we know\n    not.\n\n    So in the progress of moral development we endeavor to prove its\n    existence and the mode of its operation, but why that mode should\n    exist, rather than some other mode, we cannot explain.\n\n    The moral progress of the species depends, of course, on the moral\n    progress of the individuals embraced in it. Religion is the sum of\n    those influences which determine the motives of men\u2019s actions into\n    harmony with the Divine perfection and the Divine will. Obedience to\n    these influences constitutes the practice of religion, while the\n    statement of the growth and operation of these influences\n    constitutes the theory of religion, or doctrine.\n\n    The Divine Spirit planted in man shows him that which is in harmony\n    with the Divine Mind, and it remains for his free will to conform to\n    it or reject it. This harmony is man\u2019s highest ideal of happiness,\n    and in seeking it, as well as in desiring to flee from dissonance or\n    pain, he but obeys the disposition common to all conscious beings.\n    If, however, he attempts to conform to it, he will find the law of\n    evil present, and frequently obtaining the mastery. If now he be in\n    any degree observing, he will find that the laws of morality and\n    right are the only ones by which human society exists in a condition\n    superior to that of the lower animals, and in which the capacities\n    of man for happiness can approach a state of satisfaction. He may be\n    then said to be \u201cawakened\u201d to the importance of religion. If he\n    carry on the struggle to attain to the high goal presented to his\n    spiritual vision, he will be deeply grieved and humbled at his\n    failures: then he is said to be \u201cconvicted.\u201d Under these\n    circumstances the necessity of a deliverance becomes clear, and is\n    willingly accepted in the only way in which it has pleased the\n    Author of all to present it, which has been epitomized by Paul as\n    \u201cthe washing of regeneration and renewal of the Holy Spirit through\n    Jesus Christ.\u201d Thus a life of advanced and ever-advancing moral\n    excellence becomes possible, and the man makes nearer approaches to\n    the \u201cimage of God.\u201d\n\n    Thus is opened a new era in spiritual development, which we are led\n    to believe leads to an ultimate condition in which the nature\n    inherited from our origin is entirely overcome, and an existence of\n    moral perfection entered on. Thus in the book of Mark the simile\n    occurs: \u201cFirst the blade, then the ear, after that the full corn in\n    the ear;\u201d and Solomon says that the development of righteousness\n    \u201cshines more and more unto the perfect day.\u201d\n\n                              \u03b4. Summary.\n\n    If it be true that general development in morality proceeds in spite\n    of the original predominance of evil in the world, through the\n    self-destructive nature of the latter, it is only necessary to\n    examine the reasons why the excellence of the good may have been\n    subject also to progress, and how the remainder of the race may have\n    been influenced thereby.\n\n    The development of morality is then probably to be understood in the\n    following sense: Since the Divine Spirit, as the prime force in\n    moral progress, cannot in itself be supposed to have been in any way\n    under the influence of natural laws, its capacities were no doubt as\n    eternal and unerring in the first man as in the last. But the facts\n    and probabilities discussed above point to development of _religious\n    sensibility_, or capacity to appreciate moral good, or to receive\n    impressions from the source of good.\n\n    The evidence of this is supposed to be seen in\u2014_First_, improvement\n    in man\u2019s views of his duty to his neighbor; and _Second_, the\n    substitution of spiritual for symbolic religions: in other words,\n    improvement in the capacity for receiving spiritual impressions.\n\n    What the primary cause of this supposed development of religious\n    sensibility may have been, is a question we reverently leave\n    untouched. That it is intimately connected in some way with, and in\n    part dependent on, the evolution of the intelligence, appears very\n    probable: for this evolution is seen\u2014_First_, in a better\n    understanding of the consequences of action, and of good and of evil\n    in many things; and _Second_, in the production of means for the\n    spread of the special instrumentalities of good. The following may\n    be enumerated as such instrumentalities:\n\n    1. Furnishing literary means of record and distribution of the\n    truths of religion, morality and science.\n\n    2. Creating and increasing modes of transportation of teachers and\n    literary means of disseminating truth.\n\n    3. Facilitating the migration and the spread of nations holding the\n    highest position in the scale of morality.\n\n    4. The increase of wealth, which multiplies the extent of the\n    preceding means.\n\n    And now, let no man attempt to set bounds to this development. Let\n    no man say even that morality accomplished is all that is required\n    of mankind, since that is not necessarily the evidence of a\n    spiritual development. If a man possess the capacity for progress\n    beyond the condition in which he finds himself, in refusing to enter\n    upon it he declines to conform to the Divine law. And \u201cfrom those to\n    whom little is given, little is required, but from those to whom\n    much is given, much shall be required.\u201d\n\n\n------------------------------------------------------------------------\n\n\n\n\n                          _SCIENTIFIC ADDRESSES._\n\n\n\n\n------------------------------------------------------------------------\n\n\n\n\n                          TYNDALL\u2019S ADDRESSES.\n\n\n                                   I.\n\n       _On the Methods and Tendencies of Physical Investigation._\n\n    The celebrated Fichte, in his lectures on the \u201cVocation of the\n    Scholar,\u201d insisted on a culture for the scholar which should not be\n    one-sided, but all-sided. His intellectual nature was to expand\n    spherically, and not in a single direction. In one direction,\n    however, Fichte required that the scholar should apply himself\n    directly to nature, become a creator of knowledge, and thus repay,\n    by original labors of his own, the immense debt he owed to the\n    labors of others. It was these which enabled him to supplement the\n    knowledge derived from his own researches, so as to render his\n    culture rounded, and not one-sided.\n\n    Fichte\u2019s idea is to some extent illustrated by the constitution and\n    the labors of the British Association. We have here a body of men\n    engaged in the pursuit of natural knowledge, but variously engaged.\n    While sympathizing with each of its departments, and supplementing\n    his culture by knowledge drawn from all of them, each student\n    amongst us selects one subject for the exercise of his own original\n    faculty\u2014one line along which he may carry the light of his private\n    intelligence a little way into the darkness by which all knowledge\n    is surrounded. Thus, the geologist faces the rocks; the biologist\n    fronts the conditions and phenomena of life; the astronomer, stellar\n    masses and motions; the mathematician the properties of space and\n    number; the chemist pursues his atoms, while the physical\n    investigator has his own large field in optical, thermal,\n    electrical, acoustical, and other phenomena. The British\n    Association, then, faces nature on all sides, and pushes knowledge\n    centrifugally outwards, while, through circumstance or natural bent,\n    each of its working members takes up a certain line of research in\n    which he aspires to be an original producer, being content in all\n    other directions to accept instruction from his fellow-men. The sum\n    of our labors constitutes what Fichte might call the sphere of\n    natural knowledge. In the meetings of the Association it is found\n    necessary to resolve this sphere into its component parts, which\n    take concrete form under the respective letters of our sections.\n\n    This section (A) is called the Mathematical and Physical section.\n    Mathematics and Physics have been long accustomed to coalesce, and\n    hence this grouping. For while mathematics, as a product of the\n    human mind, is self-sustaining and nobly self-rewarding,\u2014while the\n    pure mathematician may never trouble his mind with considerations\n    regarding the phenomena of the material universe, still the form of\n    reasoning which he employs, the power which the organization of that\n    reasoning confers, the applicability of his abstract conceptions to\n    actual phenomena, render his science one of the most potent\n    instruments in the solution of natural problems. Indeed, without\n    mathematics, expressed or implied, our knowledge of physical science\n    would be friable in the extreme.\n\n    Side by side with the mathematical method, we have the method of\n    experiment. Here, from a starting-point furnished by his own\n    researches or those of others, the investigator proceeds by\n    combining intuition and verification. He ponders the knowledge he\n    possesses and tries to push it further, he guesses and checks his\n    guess, he conjectures and confirms or explodes his conjecture. These\n    guesses and conjectures are by no means leaps in the dark; for\n    knowledge once gained casts a faint light beyond its own immediate\n    boundaries. There is no discovery so limited as not to illuminate\n    something beyond itself. The force of intellectual penetration into\n    this penumbral region which surrounds actual knowledge is not\n    dependent upon method, but is proportional to the genius of the\n    investigator. There is, however, no genius so gifted as not to need\n    control and verification. The profoundest minds know best that\n    nature\u2019s ways are not at all times their ways, and that the\n    brightest flashes in the world of thought are incomplete until they\n    have been proved to have their counterparts in the world of fact.\n    The vocation of the true experimentalist is the incessant correction\n    and realization of his insight; his experiments finally constituting\n    a body, of which his purified intuitions are, as it were, the soul.\n\n    Partly through mathematical, and partly through experimental\n    research, physical science has of late years assumed a momentous\n    position in the world. Both in a material and in an intellectual\n    point of view it has produced, and it is destined to produce,\n    immense changes, vast social ameliorations, and vast alterations in\n    the popular conception of the origin, rule, and governance of\n    things. Miracles are wrought by science in the physical world, while\n    philosophy is forsaking its ancient metaphysical channels, and\n    pursuing those opened or indicated by scientific research. This must\n    become more and more the case as philosophic writers become more\n    deeply imbued with the methods of science, better acquainted with\n    the facts which scientific men have won, and with the great theories\n    which they have elaborated.\n\n    If you look at the face of a watch, you see the hour and\n    minute-hands, and possibly also a second-hand, moving over the\n    graduated dial. Why do these hands move, and why are their relative\n    motions such as they are observed to be? These questions cannot be\n    answered without opening the watch, mastering its various parts, and\n    ascertaining their relationship to each other. When this is done, we\n    find that the observed motion of the hands follows of necessity from\n    the inner mechanism of the watch when acted upon by the force\n    invested in the spring.\n\n    This motion of the hands may be called a phenomenon of art, but the\n    case is similar with the phenomena of Nature. These also have their\n    inner mechanism, and their store of force to set that mechanism\n    going. The ultimate problem of physical science is to reveal this\n    mechanism, to discern this store, and to show that from the combined\n    action of both, the phenomena of which they constitute the basis\n    must of necessity flow.\n\n    I thought that an attempt to give you even a brief and sketchy\n    illustration of the manner in which scientific thinkers regard this\n    problem would not be uninteresting to you on the present occasion;\n    more especially as it will give me occasion to say a word or two on\n    the tendencies and limits of modern science, to point out the region\n    which men of science claim as their own, and where it is mere waste\n    of time to oppose their advance, and also to define, if possible,\n    the bourne between this and that other region to which the\n    questionings and yearnings of the scientific intellect are directed\n    in vain.\n\n    But here your tolerance will be needed. It was the American Emerson,\n    I think, who said that it is hardly possible to state any truth\n    strongly without apparent injury to some other truth. Under the\n    circumstances, the proper course appears to be to state both truths\n    strongly, and allow each its fair share, in the formation of the\n    resultant conviction. For truth is often of a dual character, taking\n    the form of a magnet with two poles; and many of the differences\n    which agitate the thinking part of mankind are to be traced to the\n    exclusiveness with which different parties affirm one half of the\n    duality in forgetfulness of the other half. But this waiting for the\n    statement of the two sides of a question implies patience. It\n    implies a resolution to suppress indignation if the statement of the\n    one half should clash with our convictions, and not to suffer\n    ourselves to be unduly elated if the half-statement should chime in\n    with our views. It implies a determination to wait calmly for the\n    statement of the whole before we pronounce judgment either in the\n    form of acquiescence or dissent.\n\n    This premised, let us enter upon our task. There have been writers\n    who affirmed that the pyramids of Egypt were the productions of\n    nature; and in his early youth Alexander Von Humboldt wrote an essay\n    with the express object of refuting this notion. We now regard the\n    pyramids as the work of men\u2019s hands, aided probably by machinery of\n    which no record remains. We picture to ourselves the swarming\n    workers toiling at those vast erections, lifting the inert stones,\n    and, guided by the volition, the skill, and possibly at times by the\n    whip of the architect, placing the stones in their proper positions.\n    The blocks in this case were moved by a power external to\n    themselves, and the final form of the pyramid expressed the thought\n    of its human builder.\n\n    Let us pass from this illustration of building power to another of a\n    different kind. When a solution of common salt is slowly evaporated,\n    the water which holds the salt in solution disappears, but the salt\n    itself remains behind. At a certain stage of concentration, the salt\n    can no longer retain the liquid form; its particles, or molecules,\n    as they are called, begin to deposit themselves as minute solids, so\n    minute, indeed, as to defy all microscopic power. As evaporation\n    continues solidification goes on, and we finally obtain, through the\n    clustering together of innumerable molecules, a finite mass of salt\n    of a definite form. What is this form? It sometimes seems a mimicry\n    of the architecture of Egypt. We have little pyramids built by the\n    salt, terrace above terrace from base to apex, forming thus a series\n    of steps resembling those up which the Egyptian traveler is dragged\n    by his guides. The human mind is as little disposed to look at these\n    pyramidal salt-crystals without further question as to look at the\n    pyramids of Egypt without inquiring whence they came. How, then, are\n    those salt pyramids built up?\n\n    Guided by analogy, you may suppose that, swarming among the\n    constituent molecules of the salt, there is an invisible population,\n    guided and coerced by some invisible master, and placing the atomic\n    blocks in their positions. This, however, is not the scientific\n    idea, nor do I think your good sense will accept it as a likely one.\n    The scientific idea is that the molecules act upon each other\n    without the intervention of slave labor; that they attract each\n    other and repel each other at certain definite points, and in\n    certain definite directions; and that the pyramidal form is the\n    result of this play of attraction and repulsion. While, then, the\n    blocks of Egypt were laid down by a power external to themselves,\n    these molecular blocks of salt are self-posited, being fixed in\n    their places by the forces with which they act upon each other.\n\n    I take common salt as an illustration, because it is so familiar to\n    us all; but almost any other substance would answer my purpose\n    equally well. In fact, throughout inorganic nature, we have this\n    formative power, as Fichte would call it\u2014this structural energy\n    ready to come into play, and build the ultimate particles of matter\n    into definite shapes. It is present everywhere. The ice of our\n    winters and of our polar regions is its hand-work, and so equally\n    are the quartz, feldspar, and mica of our rocks. Our chalk-beds are\n    for the most part composed of minute shells, which are also the\n    product of structural energy; but behind the shell, as a whole, lies\n    the result of another and more subtle formative act. These shells\n    are built up of little crystals of calc-spar, and to form these the\n    structural force had to deal with the intangible molecules of\n    carbonate of lime. This tendency on the part of matter to organize\n    itself, to grow into shape, to assume definite forms in obedience to\n    the definite action of force, is, as I have said, all-pervading. It\n    is in the ground on which you tread, in the water you drink, in the\n    air you breathe. Incipient life, in fact, manifests itself\n    throughout the whole of what we call inorganic nature.\n\n    The forms of minerals resulting from this play of forces are\n    various, and exhibit different degrees of complexity. Men of science\n    avail themselves of all possible means of exploring this molecular\n    architecture. For this purpose they employ in turn as agents of\n    exploration, light, heat, magnetism, electricity, and sound.\n    Polarized light is especially useful and powerful here. A beam of\n    such light, when sent in among the molecules of a crystal, is acted\n    on by them, and from this action we infer with more or less of\n    clearness the manner in which the molecules are arranged. The\n    difference, for example, between the inner structure of a plate of\n    rock-salt and a plate of crystalized sugar or sugar-candy is thus\n    strikingly revealed. These differences may be made to display\n    themselves in phenomena of color of great splendor, the play of\n    molecular force being so regulated as to remove certain of the\n    colored constituents of white light, and to leave others with\n    increased intensity behind.\n\n    And now let us pass from what we are accustomed to regard as a dead\n    mineral to a living grain of corn. When it is examined by polarized\n    light, chromatic phenomena similar to those noticed in crystals are\n    observed. And why? Because the architecture of the grain resembles\n    in some degree the architecture of the crystal. In the corn the\n    molecules are also set in definite positions, from which they act\n    upon the light. But what has built together the molecules of the\n    corn? I have already said, regarding crystalline architecture, that\n    you may, if you please, consider the atoms and molecules to be\n    placed in position by a power external to themselves. The same\n    hypothesis is open to you now. But, if in the case of crystals you\n    have rejected this notion of an external architect, I think you are\n    bound to reject it now, and to conclude that the molecules of the\n    corn are self-posited by the forces with which they act upon each\n    other. It would be poor philosophy to invoke an external agent in\n    the one case and to reject it in the other.\n\n    Instead of cutting our grain into thin slices and subjecting it to\n    the action of polarized light, let us place it in the earth and\n    subject it to a certain degree of warmth. In other words, let the\n    molecules, both of the corn and of the surrounding earth, be kept in\n    a state of agitation; for warmth, as most of you know, is, in the\n    eye of science, tremulous molecular motion. Under these\n    circumstances, the grain and the substances which surround it\n    interact, and a molecular architecture is the result of this\n    interaction. A bud is formed; this bud reaches the surface, where it\n    is exposed to the sun\u2019s rays, which are also to be regarded as a\n    kind of vibratory motion. And as the common motion of heat with\n    which the grain and the substances surrounding it were first\n    endowed, enable the grain and these substances to coalesce, so the\n    specific motion of the sun\u2019s rays now enables the green bud to feed\n    upon the carbonic acid and the aqueous vapor of the air,\n    appropriating those constituents of both for which the blade has an\n    elective attraction, and permitting the other constituent to resume\n    its place in the air. Thus forces are active at the root, forces are\n    active in the blade, the matter of the earth and the matter of the\n    atmosphere are drawn towards the plant, and the plant augments in\n    size. We have in succession, the bud, the stalk, the ear, the full\n    corn in the ear. For the forces here at play act in a cycle, which\n    is completed by the production of grains similar to that with which\n    the process began.\n\n    Now there is nothing in this process which necessarily eludes the\n    power of mind as we know it. An intellect the same kind as our own,\n    would, if only sufficiently expanded, be able to follow the whole\n    process from beginning to end. No entirely new intellectual faculty\n    would be needed for this purpose. The duly expanded mind would see\n    in the process and its consummation an instance of the play of\n    molecular force. It would see every molecule placed in its position\n    by the specific attractions and repulsions exerted between it and\n    other molecules. Nay, given the grain and its environment, an\n    intellect the same in kind as our own, but sufficiently expanded,\n    might trace out _\u00e0 priori_ every step of the process, and by the\n    application of mechanical principles would be able to demonstrate\n    that the cycle of actions must end, as it is seen to end, in the\n    reproduction of forms like that with which the operation began. A\n    similar necessity rules here to that which rules the planets in\n    their circuits round the sun.\n\n    You will notice that I am stating my truth strongly, as at the\n    beginning we agreed it should be stated. But I must go still\n    further, and affirm that in the eye of science the animal body is\n    just as much the product of molecular force as the stalk and ear of\n    corn, or as the crystal of salt or sugar. Many of its parts are\n    obviously mechanical. Take the human heart, for example, with its\n    exquisite system of valves, or take the eye or the hand. Animal\n    heat, moreover, is the same in kind as the heat of a fire, being\n    produced by the same chemical process. Animal motion, too, is as\n    directly derived from the food of the animal, as the motion of\n    Trevethyck\u2019s walking-engine from the fuel in its furnace. As regards\n    matter, the animal body creates nothing; as regards force, it\n    creates nothing. Which of you by taking thought can add one cubit to\n    his stature? All that has been said regarding the plant may be\n    re-stated with regard to the animal. Every particle that enters into\n    the composition of the muscle, a nerve, or a bone, has been placed\n    in its position by molecular force. And unless the existence of law\n    in these matters be denied, and the element of caprice be\n    introduced, we must conclude that, given the relation of any\n    molecule of the body to its environment, its position in the body\n    might be predicted. Our difficulty is not with the quality of the\n    problem, but with its complexity; and this difficulty might be met\n    by the simple expansion of the faculties which man now possesses.\n    Given this expansion, and given the necessary molecular data, and\n    the chick might be deduced as rigorously and as logically from the\n    egg as the existence of Neptune was deduced from the disturbances of\n    Uranus, or as conical refraction was deduced from the undulatory\n    theory of light.\n\n    You see I am not mincing matters, but avowing nakedly what many\n    scientific thinkers more or less distinctly believe. The formation\n    of a crystal, a plant, or an animal, is in their eyes a purely\n    mechanical problem, which differs from the problems of ordinary\n    mechanics in the smallness of the masses and the complexity of the\n    processes involved. Here you have one half of our dual truth; let us\n    now glance at the other half. Associated with this wonderful\n    mechanism of the animal body we have phenomena no less certain than\n    those of physics, but between which and the mechanism we discern no\n    necessary connection. A man, for example, can say I feel, I think, I\n    love; but how does consciousness infuse itself into the problem? The\n    human brain is said to be the organ of thought and feeling; when we\n    are hurt the brain feels it, when we ponder it is the brain that\n    thinks, when our passions or affections are excited it is through\n    the instrumentality of the brain. Let us endeavor to be a little\n    more precise here. I hardly imagine that any profound scientific\n    thinker who has reflected upon the subject exists, who would not\n    admit the extreme probability of the hypothesis, that for every fact\n    of consciousness, whether in the domain of sense, of thought, or of\n    emotion, a certain definite molecular condition is set up in the\n    brain; that this relation of physics to consciousness is invariable,\n    so that, given the state of the brain, the corresponding thought or\n    feeling might be inferred; or, given the thought or feeling, the\n    corresponding state of the brain might be inferred. But how\n    inferred? It is at bottom not a case of logical inference at all,\n    but of empirical association. You may reply that many of the\n    inferences of science are of this character; the inference, for\n    example, that an electric current of a given direction will deflect\n    a magnetic needle in a definite way; but the cases differ in this,\n    that the passage from the current to the needle, if not\n    demonstrable, is thinkable, and that we entertain no doubt as to the\n    final mechanical solution of the problem; but the passage from the\n    physics of the brain to the corresponding facts of consciousness is\n    unthinkable. Granted that a definite thought and a definite\n    molecular action in the brain occur simultaneously, we do not\n    possess the intellectual organ, nor, apparently, any rudiment of the\n    organ, which would enable us to pass by a process of reasoning from\n    the one phenomenon to the other. They appear together, but we do not\n    know why. Were our minds and senses so expanded, strengthened, and\n    illuminated as to enable us to see and feel the very molecules of\n    the brain; were we capable of following all their motions, all their\n    groupings, all their electric discharges, if such there be; and were\n    we intimately acquainted with the corresponding states of thought\n    and feeling, we should be as far as ever from the solution of the\n    problem. \u201cHow are these physical processes connected with the facts\n    of consciousness?\u201d The chasm between the two classes of phenomena\n    would still remain intellectually impassable. Let the consciousness\n    of love, for example, be associated with a right-handed spiral\n    motion of the molecules of the brain, and the consciousness of hate\n    with a left-handed spiral motion. We should then know when we love\n    that the motion is in one direction, and when we hate that the\n    motion is in the other; but the \u201cWHY?\u201d would still remain\n    unanswered.\n\n    In affirming that the growth of the body is mechanical, and that\n    thought, as exercised by us, has its correlative in the physics of\n    the brain, I think the position of the \u201cMaterialist\u201d is stated as\n    far as that position is a tenable one. I think the materialist will\n    be able finally to maintain this position against all attacks; but I\n    do not think, as the human mind is at present constituted, that he\n    can pass beyond it. I do not think he is entitled to say that his\n    molecular groupings and his molecular motions explain everything. In\n    reality they explain nothing. The utmost he can affirm is the\n    association of two classes of phenomena of whose real bond of union\n    he is in absolute ignorance. The problem of the connection of the\n    body and soul is as insoluble in its modern form as it was in the\n    pre-scientific ages. Phosphorus is known to enter into the\n    composition of the human brain, and a courageous writer has\n    exclaimed, in his trenchant German, \u201cOhne phosphor kein gedanke.\u201d\n    That may or may not be the case; but even if we knew it to be the\n    case, the knowledge would not lighten our darkness. On both sides of\n    the zone here assigned to the materialist he is equally helpless. If\n    you ask him whence is this \u201cmatter\u201d of which we have been\n    discoursing, who or what divided it into molecules, who or what\n    impressed upon them this necessity of running into organic forms, he\n    has no answer. Science also is mute in reply to these questions. But\n    if the materialist is confounded, and science rendered dumb, who\n    else is entitled to answer? To whom has the secret been revealed?\n    Let us lower our heads and acknowledge our ignorance, one and all.\n    Perhaps the mystery may resolve itself into knowledge at some future\n    day. The process of things upon this earth has been one of\n    amelioration. It is a long way from the Iguanodon and his\n    contemporaries to the president and members of the British\n    Association. And whether we regard the improvement from the\n    scientific or from the theological point of view as the result of\n    progressive development, or as the result of successive exhibitions\n    of creative energy, neither view entitles us to assume that man\u2019s\n    present faculties end the series\u2014that the process of amelioration\n    stops at him. A time may therefore come when this ultra-scientific\n    region by which we are now enfolded may offer itself to terrestrial,\n    if not to human investigation. Two-thirds of the rays emitted by the\n    sun fail to arouse in the eye the sense of vision. The rays exist,\n    but the visual organ requisite for their translation into light does\n    not exist. And so from this region of darkness and mystery which\n    surrounds us, rays may now be darting which require but the\n    development of the proper intellectual organs to translate them into\n    knowledge as far surpassing ours as ours does that of the wallowing\n    reptiles which once held possession of this planet. Meanwhile the\n    mystery is not without its uses. It certainly may be made a power in\n    the human soul; but it is a power which has feeling, not knowledge,\n    for its base. It may be, and will be, and we hope is turned to\n    account, both in steadying and strengthening the intellect, and in\n    rescuing man from that littleness to which, in the struggle for\n    existence or for precedence in the world, he is continually prone.\n\n                                  II.\n\n                           On Haze and Dust.\n\n    Solar light in passing through a dark room reveals its track by\n    illuminating the dust floating in the air. \u201cThe sun,\u201d says Daniel\n    Culverwell, \u201cdiscovers atomes, though they be invisible by\n    candle-light, and makes them dance naked in his beams.\u201d\n\n    In my researches on the decomposition of vapors by light, I was\n    compelled to remove these \u201catomes\u201d and this dust. It was essential\n    that the space containing the vapors should embrace no visible\n    thing; that no substance capable of scattering the light in the\n    slightest sensible degree should, at the outset of an experiment, be\n    found in the \u201cexperimental tube\u201d traversed by the luminous beam.\n\n    For a long time I was troubled by the appearance there of floating\n    dust, which, though invisible in diffuse daylight, was at once\n    revealed by a powerfully condensed beam. Two tubes were placed in\n    succession in the path of the dust: the one containing fragments of\n    glass wetted with concentrated sulphuric acid; the other, fragments\n    of marble wetted with a strong solution of caustic potash. To my\n    astonishment it passed through both. The air of the Royal\n    Institution, sent through these tubes at a rate sufficiently slow to\n    dry it and to remove its carbonic acid, carried into the\n    experimental tube a considerable amount of mechanically-suspended\n    matter, which was illuminated when the beam passed through the tube.\n    The effect was substantially the same when the air was permitted to\n    bubble through the liquid acid and through the solution of potash.\n\n    Thus, on the 5th of October, 1868, successive charges of air were\n    admitted through the potash and sulphuric acid into the exhausted\n    experimental tube. Prior to the admission of the air the tube was\n    _optically empty_; it contained nothing competent to scatter the\n    light. After the air had entered the tube, the conical track of the\n    electric beam was in all cases clearly revealed. This, indeed, was a\n    daily observation at the time to which I now refer.\n\n    I tried to intercept this floating matter in various ways; and on\n    the day just mentioned, prior to sending the air through the drying\n    apparatus, I carefully permitted it to pass over the tip of a\n    spirit-lamp flame. The floating matter no longer appeared, having\n    been burnt up by the flame. It was, therefore, _organic matter_.\n    When the air was sent too rapidly through the flame, a fine blue\n    cloud was found in the experimental tube. This was the _smoke_ of\n    the organic particles. I was by no means prepared for this result;\n    for I had thought, with the rest of the world, that the dust of our\n    air was, in great part, inorganic and non-combustible.\n\n    Mr. Valentin had the kindness to procure for me a small gas-furnace,\n    containing a platinum tube, which could be heated to vivid redness.\n    The tube also contained a roll of platinum gauze, which, while it\n    permitted the air to pass through it, insured the practical contact\n    of the dust with the incandescent metal. The air of the laboratory\n    was permitted to enter the experimental tube, sometimes through the\n    cold, and sometimes through the heated tube of platinum. The\n    rapidity of admission was also varied. In the first column of the\n    following table the quantity of air operated on is expressed by the\n    number of inches which the mercury gauge of the air-pump sank when\n    the air entered. In the second column the condition of the platinum\n    tube is mentioned, and in the third the state of the air which\n    entered the experimental tube.\n\n                        State of        State of\n             Quantity   Platinum        Experimental\n             of Air.    Tube.           Tube.\n\n             15 inches  Cold            Full of particles.\n\n             15 inches  Red-hot         Optically empty.\n\n             15 inches  Cold            Full of particles.\n\n             15 inches  Red-hot         Optically empty.\n\n             15 inches  Cold            Full of particles.\n\n             15 inches  Red-hot         Optically empty.\n\n\n    The phrase \u201coptically empty\u201d shows that when the conditions of\n    perfect combustion were present, the floating matter totally\n    disappeared. It was wholly burnt up, leaving not a trace of residue.\n    From spectrum analysis, however, we know that soda floats in the\n    air; these organic dust particles are, I believe, the _rafts_ that\n    support it, and when they are removed it sinks and vanishes.\n\n    When the passage of the air was so rapid as to render imperfect the\n    combustion of the floating matter, instead of optical emptiness a\n    fine blue cloud made its appearance in the experimental tube. The\n    following series of results illustrate this point:\n\n\n        Quantity.         Platinum Tube.    Experimental Tube.\n        15 inches, slow   Cold              Full of particles.\n        15 inches, slow   Red-hot           Optically empty.\n        15 inches, quick  Red-hot           A blue cloud.\n        15 inches, quick  Intensely hot     A fine blue cloud.\n\n\n    The optical character of these clouds was totally different from\n    that of the dust which produced them. At right angles to the\n    illuminating beam they discharged perfectly polarized light The\n    cloud could be utterly quenched by a transparent Nicol\u2019s prism, and\n    the tube containing it reduced to optical emptiness.\n\n    The particles floating in the air of London being thus proved to be\n    organic, I sought to burn them up at the focus of a concave\n    reflector. One of the powerfully convergent mirrors employed in my\n    experiments on combustion by dark rays was here made use of, but I\n    failed in the attempt. Doubtless the floating particles are in part\n    transparent to radiant heat, and are so far incombustible by such\n    heat. Their rapid motion through the focus also aids their escape.\n    They do not linger there sufficiently long to be consumed. A flame\n    it was evident would burn them up, but I thought the presence of the\n    flame would mask its own action among the particles.\n\n    In a cylindrical beam, which powerfully illuminated the dust of the\n    laboratory, was placed an ignited spirit-lamp. Mingling with the\n    flame, and round its rim, were seen wreaths of darkness resembling\n    an intensely black smoke. On lowering the flame below the beam the\n    same dark masses stormed upwards. They were at times blacker than\n    the blackest smoke that I have ever seen issuing from the funnel of\n    a steamer, and their resemblance to smoke was so perfect as to lead\n    the most practiced observer to conclude that the apparently pure\n    flame of the alcohol lamp required but a beam of sufficient\n    intensity to reveal its clouds of liberated carbon.\n\n    But is the blackness smoke? The question presented itself in a\n    moment. A red-hot poker was placed underneath the beam, and from it\n    the black wreaths also ascended. A large hydrogen flame was next\n    employed, and it produced those whirling masses of darkness far more\n    copiously than either the spirit-flame or poker. Smoke was,\n    therefore, out of the question.\n\n    What, then, was the blackness? It was simply that of stellar space;\n    that is to say, blackness resulting from the absence from the track\n    of the beam of all matter competent to scatter its light. When the\n    flame was placed below the beam the floating matter was destroyed\n    _in situ_; and the air, freed from this matter, rose into the beam,\n    jostled aside the illuminated particles and substituted for their\n    light the darkness due to its own perfect transparency. Nothing\n    could more forcibly illustrate the invisibility of the agent which\n    renders all things visible. The beam crossed, unseen, the black\n    chasm formed by the transparent air, while at both sides of the gap\n    the thick-strewn particles shone out like a luminous solid under the\n    powerful illumination.\n\n    But here a difficulty meets us. It is not necessary to burn the\n    particles to produce a stream of darkness. Without actual\n    combustion, currents may be generated which shall exclude the\n    floating matter, and therefore appear dark amid the surrounding\n    brightness. I noticed this effect first on placing a red-hot copper\n    ball below the beam, and permitting it to remain there until its\n    temperature had fallen below that of boiling water. The dark\n    currents, though much enfeebled, were still produced. They may also\n    be produced by a flask filled with hot water.\n\n    To study this effect a platinum wire was stretched across the beam,\n    the two ends of the wire being connected with the two poles of a\n    voltaic battery. To regulate the strength of the current a rheostat\n    was placed in the circuit. Beginning with a feeble current the\n    temperature of the wire was gradually augmented, but before it\n    reached the heat of ignition, a flat stream of air rose from it,\n    which when looked at edgeways appeared darker and sharper than one\n    of the blackest lines of Fraunhofer in the solar spectrum. Right and\n    left of this dark vertical band the floating matter rose upwards,\n    bounding definitely the non-luminous stream of air. What is the\n    explanation? Simply this. The hot wire rarefied the air in contact\n    with it, but it did not equally lighten the floating matter. The\n    convection current of pure air therefore passed upwards _among the\n    particles_, dragging them after it right and left, but forming\n    between them an impassable black partition. In this way we render an\n    account of the dark currents produced by bodies at a temperature\n    below that of combustion.\n\n    Oxygen, hydrogen, nitrogen, carbonic acid, so prepared as to exclude\n    all floating particles, produce the darkness when poured or blown\n    into the beam. Coal-gas does the same. An ordinary glass shade\n    placed in the air with its mouth downwards permits the track of the\n    beam to be seen crossing it. Let coal-gas or hydrogen enter the\n    shade by a tube reaching to its top, the gas gradually fills the\n    shade from the top downwards. As soon as it occupies the space\n    crossed by the beam, the luminous track is instantly abolished.\n    Lifting the shade so as to bring the common boundary of gas and air\n    above the beam, the track flashes forth. After the shade is full, if\n    it be inverted, the gas passes upwards like a black smoke among the\n    illuminated particles.\n\n    The air of our London rooms is loaded with this organic dust, nor is\n    the country air free from its pollution. However ordinary daylight\n    may permit it to disguise itself, a sufficiently powerful beam\n    causes the air in which the dust is suspended to appear as a\n    semi-solid rather than as a gas. Nobody could, in the first\n    instance, without repugnance place the mouth at the illuminated\n    focus of the electric beam and inhale the dirt revealed there. Nor\n    is the disgust abolished by the reflection that, although we do not\n    see the nastiness, we are churning it in our lungs every hour and\n    minute of our lives. There is no respite to this contact with dirt;\n    and the wonder is, not that we should from time to time suffer from\n    its presence, but that so small a portion of it would appear to be\n    deadly to man.\n\n    And what is this portion? It was some time ago the current belief\n    that epidemic diseases generally were propagated by a kind of\n    malaria, which consisted of organic matter in a state of\n    _motor-decay_; that when such matter was taken into the body through\n    the lungs or skin, it had the power of spreading there the\n    destroying process which had attacked itself. Such a spreading power\n    was visibly exerted in the case of yeast. A little leaven was seen\n    to leaven the whole lump, a mere speck of matter in this supposed\n    state of decomposition being apparently competent to propagate\n    indefinitely its own decay. Why should not a bit of rotten malaria\n    work in a similar manner within the human frame? In 1836 a very\n    wonderful reply was given to this question. In that year Cagniard de\n    la Tour discovered the _yeast plant_, a living organism, which, when\n    placed in a proper medium, feeds, grows, and reproduces itself, and\n    in this way carries on the process which we name fermentation.\n    Fermentation was thus proved to be a product of life instead of a\n    process of decay.\n\n    Schwann, of Berlin, discovered the yeast plant independently, and in\n    February, 1837, he also announced the important result, that when a\n    decoction of meat is effectually screened from ordinary air, and\n    supplied solely with air which has been raised to a high\n    temperature, putrefaction never sets in. Putrefaction, therefore, he\n    affirmed to be caused by something derived from the air, which\n    something could be destroyed by a sufficiently high temperature. The\n    experiments of Schwann were repeated and confirmed by Helmholtz and\n    Ure. But as regards fermentation, the minds of chemists, influenced\n    probably by the great authority of Gay-Lussac, who ascribed\n    putrefaction to the action of oxygen, fell back upon the old notion\n    of matter in a state of decay. It was not the living yeast plant,\n    but the dead or dying parts of it, which, assailed by oxygen,\n    produced the fermentation. This notion was finally exploded by\n    Pasteur. He proved that the so-called \u201cferments\u201d are not such; that\n    the true ferments are organized beings which find in the reputed\n    ferments their necessary food.\n\n    Side by side with these researches and discoveries, and fortified by\n    them and others, has run the _germ theory_ of epidemic disease. The\n    notion was expressed by Kircher, and favored by Linn\u00e6us, that\n    epidemic diseases are due to germs which float in the atmosphere,\n    enter the body, and produce disturbance by the development within\n    the body of parasitic life. While it was still struggling against\n    great odds, this theory found an expounder and a defender in the\n    President of this Institution. At a time when most of his medical\n    brethren considered it a wild dream, Sir Henry Holland contended\n    that some form of the germ theory was probably true. The strength of\n    this theory consists in the perfect parallelism of the phenomena of\n    contagious disease with those of life. As a planted acorn gives\n    birth to an oak competent to produce a whole crop of acorns, each\n    gifted with the power of reproducing its parent tree, and as thus\n    from a single seedling a whole forest may spring, so these epidemic\n    diseases literally plant their seeds, grow, and shake abroad new\n    germs, which, meeting in the human body their proper food and\n    temperature, finally take possession of whole populations. Thus\n    Asiatic cholera, beginning in a small way in the Delta of the\n    Ganges, contrived in seventeen years to spread itself over nearly\n    the whole habitable world. The development from an infinitesimal\n    speck of the virus of small-pox of a crop of pustules, each charged\n    with the original poison, is another illustration. The reappearance\n    of the scourge, as in the case of the _Dreadnought_ at Greenwich,\n    reported on so ably by Dr. Budd and Mr. Busk, receives a\n    satisfactory explanation from the theory which ascribes it to the\n    lingering of germs about the infected place.\n\n    Surgeons have long known the danger of permitting air to enter an\n    open abscess. To prevent its entrance they employ a tube called a\n    cannula, to which is attached a sharp steel point called a trocar.\n    They puncture with the steel point, and by gentle pressure they\n    force the pus through the cannula. It is necessary to be very\n    careful in cleansing the instrument; and it is difficult to see how\n    it can be cleansed by ordinary methods in air loaded with organic\n    impurities, as we have proved our air to be. The instrument ought,\n    in fact, to be made as hot as its temper will bear. But this is not\n    done, and hence, notwithstanding all the surgeon\u2019s care,\n    inflammation often sets in after the first operation, rendering\n    necessary a second and a third. Rapid putrefaction is found to\n    accompany this new inflammation. The pus, moreover, which was sweet\n    at first, and showed no trace of animal life, is now fetid, and\n    swarming with active little organisms called vibrios. Prof. Lister,\n    from whose recent lecture this fact is derived, contends, with every\n    show of reason, that this rapid putrefaction and this astounding\n    development of animal life are due to the entry of germs into the\n    abscess during the first operation, and their subsequent nurture and\n    development under favorable conditions of food and temperature. The\n    celebrated physiologist and physicist, Helmholtz, is attacked\n    annually by hay-fever. From the 20th of May to the end of June he\n    suffers from a catarrh of the upper air-passages; and he has found\n    during this period, and at no other, that his nasal secretions are\n    peopled by these vibrios. They appear to nestle by preference in the\n    cavities and recesses of the nose, for a strong sneeze is necessary\n    to dislodge them.\n\n    These statements sound uncomfortable; but by disclosing our enemy\n    they enable us to fight him. When he clearly eyes his quarry the\n    eagle\u2019s strength is doubled, and his swoop is rendered sure. If the\n    germ theory be proved true, it will give a definiteness to our\n    efforts to stamp out disease which they could not previously\n    possess. And it is only by definite effort under its guidance that\n    its truth or falsehood can be established. It is difficult for an\n    outsider like myself to read without sympathetic emotion such papers\n    as those of Dr. Budd, of Bristol, on cholera, scarlet-fever, and\n    small-pox. He is a man of strong imagination, and may occasionally\n    take a flight beyond his facts; but without this dynamic heat of\n    heart, the stolid inertia of the free-born Briton cannot be\n    overcome. And as long as the heat is employed to warm up the truth\n    without singeing it overmuch; as long as this enthusiasm can\n    overmatch its mistakes by unequivocal examples of success, so long\n    am I disposed to give it a fair field to work in, and to wish it God\n    speed.\n\n    But let us return to our dust. It is needless to remark that it\n    cannot be blown away by an ordinary bellows; or, more correctly, the\n    place of the particles blown away is in this case supplied by others\n    ejected from the bellows, so that the track of the beam remains\n    unimpaired. But if the nozzle of a good bellows be filled with\n    cotton wool not too tightly packed, the air urged through the wool\n    is filtered of its floating matter, and it then forms a clean band\n    of darkness in the illuminated dust. This was the filter used by\n    Schro\u00ebder in his experiments on spontaneous generation, and turned\n    subsequently to account in the excellent researches of Pasteur.\n    Since 1868 I have constantly employed it myself.\n\n    But by far the most interesting and important illustration of this\n    filtering process is furnished by the human breath. I fill my lungs\n    with ordinary air and breathe through a glass tube across the\n    electric beam. The condensation of the aqueous vapor of the breath\n    is shown by the formation of a luminous white cloud of delicate\n    texture. It is necessary to abolish this cloud, and this may be done\n    by drying the breath previous to its entering into the beam; or\n    still more simply, by warming the glass tube. When this is done the\n    luminous track of the beam is for a time uninterrupted. The breath\n    impresses upon the floating matter a transverse motion, but the dust\n    from the lungs makes good the particles displaced. But after some\n    time an obscure disc appears upon the beam, the darkness of which\n    increases, until finally, towards the end of the expiration, the\n    beam is, as it were, pierced by an intensely black hole, in which no\n    particles whatever can be discerned. The air, in fact, has so lodged\n    its dirt within the lungs as to render the last portions of the\n    expired breath absolutely free from suspended matter. This\n    experiment may be repeated any number of times with the same result.\n    It renders the distribution of the dirt within the lungs as manifest\n    as if the chest were transparent.\n\n    I now empty my lungs as perfectly as possible, and placing a handful\n    of cotton wool against my mouth and nostrils, inhale through it.\n    There is no difficulty in thus filling the lungs with air. On\n    expiring this air through the glass tube, its freedom from floating\n    matter is at once manifest. From the very beginning of the act of\n    expiration the beam is pierced by a black aperture. The first puff\n    from the lungs abolishes the illuminated dust and puts a patch of\n    darkness in its place, and the darkness continues throughout the\n    entire course of the expiration. When the tube is placed below the\n    beam and moved to and fro, the same smoke-like appearance as that\n    obtained with a flame is observed. In short, the cotton wool, when\n    used in sufficient quantity, completely intercepts the floating\n    matter on its way to the lungs.\n\n    And here we have revealed to us the true philosophy of a practice\n    followed by medical men, more from instinct than from actual\n    knowledge. In a contagious atmosphere the physician places a\n    handkerchief to his mouth and inhales through it. In doing so he\n    unconsciously holds back the dirt and germs of the air. If the\n    poison were a gas it would not be thus intercepted. On showing this\n    experiment with the cotton wool to Dr. Bence Jones, he immediately\n    repeated it with a silk handkerchief. The result was substantially\n    the same, though, as might be expected, the wool is by far the\n    surest filter. The application of these experiments is obvious. If a\n    physician wishes to hold back from the lungs of his patient, or from\n    his own, the germs by which contagious disease is said to be\n    propagated, he will employ a cotton wool respirator. After the\n    revelations of this evening, such respirators must, I think, come\n    into general use as a defence against contagion. In the crowded\n    dwellings of the London poor, where the isolation of the sick is\n    difficult, if not impossible, the noxious air around the patient\n    may, by this simple means, be restored to practical purity. Thus\n    filtered, attendants may breathe the air unharmed. In all\n    probability the protection of the lungs will be protection of the\n    entire system. For it is exceedingly probable that the germs which\n    lodge in the air-passages, and which, at their leisure, can work\n    their way across the mucous membrane, are those which sow in the\n    body epidemic disease. If this be so, then disease can certainly be\n    warded off by filters of cotton wool. I should be most willing to\n    test their efficacy in my own person. And time will decide whether\n    in lung diseases also the woolen respirator cannot abate irritation,\n    if not arrest decay. By its means, so far as the germs are\n    concerned, the air of the highest Alps may be brought into the\n    chamber of the invalid.\n\n                                  III.\n\n                   Scientific Use of the Imagination.\n\n    I carried with me to the Alps this year the heavy burden of this\n    evening\u2019s work. In the way of new investigation I had nothing\n    complete enough to be brought before you; so all that remained to me\n    was to fall back upon such residues as I could find in the depths of\n    consciousness, and out of them to spin the fiber and weave the web\n    of this discourse. Save from memory I had no direct aid upon the\n    mountains; but to spur up the emotions, on which so much depends, as\n    well as to nourish indirectly the intellect and will, I took with me\n    two volumes of poetry, Goethe\u2019s \u201cFarbenlehre,\u201d and the work on\n    \u201cLogic\u201d recently published by Mr. Alexander Bain. The spur, I am\n    sorry to say, was no match for the integument of dullness it had to\n    pierce.\n\n    In Goethe, so glorious otherwise, I chiefly noticed the\n    self-inflicted hurts of genius, as it broke itself in vain against\n    the philosophy of Newton. For a time Mr. Bain became my principal\n    companion. I found him learned and practical, shining generally with\n    a dry light, but exhibiting at times a flush of emotional strength,\n    which proved that even logicians share the common fire of humanity.\n    He interested me most when he became the mirror of my own condition.\n    Neither intellectually nor socially is it good for man to be alone,\n    and the griefs of thought are more patiently borne when we find that\n    they have been experienced by another. From certain passages in his\n    book I could infer that Mr. Bain was no stranger to such sorrows.\n    Take this passage as an illustration. Speaking of the ebb of\n    intellectual force which we all from time to time experience, Mr.\n    Bain says: \u201cThe uncertainty where to look for the next opening of\n    discovery brings the pain of conflict and the debility of\n    indecision.\u201d These words have in them the true ring of personal\n    experience.\n\n    The action of the investigator is periodic. He grapples with a\n    subject of inquiry, wrestles with it, overcomes it, exhausts, it may\n    be, both himself and it for the time being. He breathes a space, and\n    then renews the struggle in another field. Now this period of\n    halting between two investigations is not always one of pure repose.\n    It is often a period of doubt and discomfort, of gloom and ennui.\n    \u201cThe uncertainty where to look for the next opening of discovery\n    brings the pain of conflict and the debility of indecision.\u201d Such\n    was my precise condition in the Alps this year; in a score of words\n    Mr. Bain has here sketched my mental diagnosis; and it was under\n    these evil circumstances that I had to equip myself for the hour and\n    the ordeal that are now come.\n\n    Gladly, however, as I should have seen this duty in other hands, I\n    could by no means shrink from it. Disloyalty would have been worse\n    than failure. In some fashion or other\u2014feebly or strongly, meanly or\n    manfully, on the higher levels of thought, or on the flats of\n    commonplace\u2014the task had to be accomplished. I looked in various\n    directions for help and furtherance; but without me for a time I saw\n    only \u201cantres vast,\u201d and within me \u201cdeserts idle.\u201d My case resembled\n    that of a sick doctor who had forgotten his art, and sorely needed\n    the prescription of a friend. Mr. Bain wrote one for me. He said:\n    \u201cYour present knowledge must forge the links of connection between\n    what has been already achieved and what is now required.\u201d\n\n    In these words he admonished me to review the past and recover from\n    it the broken ends of former investigations. I tried to do so.\n    Previous to going to Switzerland I had been thinking much of light\n    and heat, of magnetism and electricity, of organic germs, atoms,\n    molecules, spontaneous generation, comets and skies. With one or\n    another of these I now sought to re-form an alliance, and finally\n    succeeded in establishing a kind of cohesion between thought and\n    light. The wish grew within me to trace, and to enable you to trace,\n    some of the more occult operations of this agent. I wished, if\n    possible, to take you behind the drop-scene of the senses, and to\n    show you the hidden mechanism of optical action. For I take it to be\n    well worth the while of the scientific teacher to take some pains,\n    and even great pains, to make those whom he addresses co-partners of\n    his thoughts. To clear his own mind in the first place from all haze\n    and vagueness, and then to project into language which shall leave\n    no mistake as to his meaning\u2014which shall leave even his errors\n    naked\u2014the definite ideas he has shaped.\n\n    A great deal is, I think, possible to scientific exposition\n    conducted in this way. It is possible, I believe, even before an\n    audience like the present, to uncover to some extent the unseen\n    things of nature, and thus to give, not only to professed students,\n    but to others with the necessary bias, industry and capacity, an\n    intelligent interest in the operations of science. Time and labor\n    are necessary to this result, but science is the gainer from the\n    public sympathy thus created.\n\n    How then are those hidden things to be revealed? How, for example,\n    are we to lay hold of the physical basis of light, since, like that\n    of life itself, it lies entirely without the domain of the senses?\n    Now, philosophers may be right in affirming that we cannot transcend\n    experience. But we can, at all events, carry it a long way from its\n    origin. We can also magnify, diminish, qualify, and combine\n    experiences, so as to render them fit for purposes entirely new. We\n    are gifted with the power of imagination, combining what the Germans\n    called _Anschauungsgabe_ and _Einbildungskraft_, and by this power\n    we can lighten the darkness which surrounds the world of the senses.\n\n    There are tories even in science who regard imagination as a faculty\n    to be feared and avoided rather than employed. They had observed its\n    action in weak vessels and were unduly impressed by its disasters.\n    But they might with equal justice point to exploded boilers as an\n    argument against the use of steam. Bounded and conditioned by\n    co\u00f6perant reason, imagination becomes the mightiest instrument of\n    the physical discoverer. Newton\u2019s passage from a falling apple to a\n    falling moon was a leap of the imagination. When William Thomson\n    tries to place the ultimate particles of matter between his compass\n    points, and to apply to them a scale of millimeters, it is an\n    exercise of the imagination. And in much that has been recently said\n    about protoplasm and life, we have the outgoings of the imagination\n    guided and controlled by the known analogies of science. In fact,\n    without this power our knowledge of nature would be a mere\n    tabulation of co\u00ebxistences and sequences. We should still believe in\n    the succession of day and night, of summer and winter; but the soul\n    of force would be dislodged from our universe; casual relations\n    would disappear, and with them that science which is now binding the\n    parts of nature to an organic whole.\n\n    I should like to illustrate by a few simple instances the use that\n    scientific men have already made of this power of imagination, and\n    to indicate afterwards some of the further uses that they are likely\n    to make of it. Let us begin with the rudimentary experiences.\n    Observe the falling of heavy rain drops into a tranquil pond. Each\n    drop as it strikes the water becomes a center of disturbance, from\n    which a series of ring ripples expands outwards. Gravity and inertia\n    are the agents by which this wave motion is produced, and a rough\n    experiment will suffice to show that the rate of propagation does\n    not amount to a foot a second.\n\n    A series of slight mechanical shocks is experienced by a body\n    plunged in the water as the wavelets reach it in succession. But a\n    finer motion is at the same time set up and propagated. If the head\n    and ears be immersed in the water, as in an experiment of\n    Franklin\u2019s, the shock of the drop is communicated to the auditory\n    nerve\u2014the _tick_ of the drop is heard. Now this sonorous impulse is\n    propagated, not at the rate of a foot a second, but at the rate of\n    4,700 feet a second. In this case it is not the gravity but the\n    _elasticity_ of the water that is the urging force. Every liquid\n    particle pushed against its neighbor delivers up its motion with\n    extreme rapidity, and the pulse is propagated as a thrill. The\n    incompressibility of water, as illustrated by the famous Florentine\n    experiment, is a measure of its elasticity, and to the possession of\n    this property in so high a degree the rapid transmission of a\n    sound-pulse through water is to be ascribed.\n\n    But water, as you know, is not necessary to the conduction of sound;\n    air is its most common vehicle. And you know that when the air\n    possesses the particular density and elasticity corresponding to the\n    temperature of freezing water, the velocity of sound in it is 1,090\n    feet a second. It is almost exactly one-fourth of the velocity in\n    water; the reason being that though the greater weight of the water\n    tends to diminish the velocity, the enormous molecular elasticity of\n    the liquid far more than atones for the disadvantage due to weight.\n    By various contrivances we can compel the vibrations of the air to\n    declare themselves; we know the length and frequency of sonorous\n    waves, and we have also obtained great mastery over the various\n    methods by which the air is thrown into vibration. We know the\n    phenomena and laws of vibrating rods, of organ pipes, strings,\n    membranes, plates, and bells. We can abolish one sound by another.\n    We know the physical meaning of music and noise, of harmony and\n    discord. In short, as regards sound we have a very clear notion of\n    the external physical processes which correspond to our sensations.\n\n    In these phenomena of sound we travel a very little way from\n    downright sensible experience. Still the imagination is to some\n    extent exercised. The bodily eye, for example, cannot see the\n    condensations and rarefactions of the waves of sound. We construct\n    them in thought, and we believe as firmly in their existence as in\n    that of the air itself. But now our experience has to be carried\n    into a new region, where a new use is to be made of it.\n\n    Having mastered the cause and mechanism of sound, we desire to know\n    the cause and mechanism of light. We wish to extend our inquiries\n    from the auditory nerve to the optic nerve. Now there is in the\n    human intellect a power of expansion\u2014I might almost call it a power\n    of creation\u2014which is brought into play by the simple brooding upon\n    facts. The legend of the Spirit brooding over chaos may have\n    originated in a knowledge of this power. In the case now before us\n    it has manifested itself by transplanting into space, for the\n    purposes of light, an adequately modified form of the mechanism of\n    sound. We know intimately whereon the velocity of sound depends.\n    When we lessen the density of a medium and preserve its elasticity\n    constant, we augment the velocity. When we highten the elasticity\n    and keep the density constant, we also augment the velocity. A small\n    density, therefore, and a great elasticity are the two things\n    necessary to rapid propagation.\n\n    Now light is known to move with the astounding velocity of 185,000\n    miles a second. How is such a velocity to be obtained? By boldly\n    diffusing in space a medium of the requisite tenuity and elasticity.\n    Let us make such a medium our starting point, endowing it with one\n    or two other necessary qualities; let us handle it in accordance\n    with strict mechanical laws; give to every step of your deduction\n    the surety of the syllogism; carry it thus forth from the world of\n    imagination to the world of sense, and see whether the final outcrop\n    of the deduction be not the very phenomena of light which ordinary\n    knowledge and skilled experiment reveal. If in all the multiplied\n    varieties of these phenomena, including those of the most remote and\n    entangled description, this fundamental conception always brings us\n    face to face with the truth; if no contradiction to our deductions\n    from it be found in external nature; if, moreover, it has actually\n    forced upon our attention phenomena which no eye had previously\n    seen, and which no mind had previously imagined; if by it we are\n    gifted with a power of prescience which has never failed when\n    brought to an experimental test; such a conception, which never\n    disappoints us, but always lands us on the solid shores of fact,\n    must, we think, be something more than a mere figment of the\n    scientific fancy. In forming it that composite and creative unity in\n    which reason and imagination are together blent, has, we believe,\n    led us into a world not less real than that of the senses, and of\n    which the world of sense itself is the suggestion and justification.\n\n    Far be it from me, however, to wish to fix you immovably in this or\n    in any other theoretic conception. With all our belief of it, it\n    will be well to keep the theory plastic and capable of change. You\n    may, moreover, urge that although the phenomena occur _as if_ the\n    medium existed, the absolute demonstration of its existence is still\n    wanting. Far be it from me to deny to this reasoning such validity\n    as it may fairly claim. Let us endeavor by means of analogy to form\n    a fair estimate of its force.\n\n    You believe that in society you are surrounded by reasonable beings\n    like yourself. You are, perhaps, as firmly convinced of this as of\n    anything. What is your warrant for this conviction? Simply and\n    solely this, your fellow-creatures behave as if they were\n    reasonable; the hypothesis, for it is nothing more, accounts for the\n    facts. To take an eminent example, you believe that our president is\n    a reasonable being. Why? There is no known method of superposition\n    by which any one of us can apply himself intellectually to another\n    so as to demonstrate coincidence as regards the possession of\n    reason. If, therefore, you hold our president to be reasonable, it\n    is because he behaves _as if_ he were reasonable. As in the case of\n    the ether, beyond the \u201c_as if_\u201d you cannot go. Nay, I should not\n    wonder if a close comparison of the data on which both inferences\n    rest caused many respectable persons to conclude that the ether had\n    the best of it.\n\n    This universal medium, this light-ether as it is called, is a\n    vehicle, not an origin of wave motion. It receives and transmits,\n    but it does not create. Whence does it derive the motions it\n    conveys? For the most part from luminous bodies. By this motion of a\n    luminous body I do not mean its sensible motion, such as the flicker\n    of a candle, or the shooting out of red prominences from the limb of\n    the sun. I mean an intestine motion of the atoms or molecules of the\n    luminous body. But here a certain reserve is necessary. Many\n    chemists of the present day refuse to speak of atoms and molecules\n    as real things. Their caution leads them to stop short of the clear,\n    sharp, mechanically intelligible atomic theory enunciated by Dalton,\n    or any form of that theory, and to make the doctrine of multiple\n    proportions their intellectual bourne. I respect the caution, though\n    I think it is here misplaced. The chemists who recoil from these\n    notions of atoms and molecules accept without hesitation the\n    undulatory theory of light. Like you and me they one and all believe\n    in an ether and its light-producing waves. Let us consider what this\n    belief involves.\n\n    Bring your imaginations once more into play and figure a series of\n    sound waves passing through air. Follow them up to their origin, and\n    what do you there find? A definite, tangible, vibrating body. It may\n    be the vocal chords of a human being, it may be an organ pipe, or it\n    may be a stretched string. Follow in the same manner a train of\n    ether waves to their source, remembering at the same time that your\n    ether is matter, dense, elastic, and capable of motions subject to\n    and determined by mechanical laws. What then do you expect to find\n    as the source of a series of ether waves? Ask your imagination if it\n    will accept a vibrating multiple proportion\u2014a numerical ratio in a\n    state of oscillation? I do not think it will. You cannot crown the\n    edifice by this abstraction. The scientific imagination, which is\n    here authoritative, demands as the origin and cause of a series of\n    ether waves a particle of vibrating matter quite as definite, though\n    it may be excessively minute, as that which gives origin to a\n    musical sound. Such a particle we name an atom or a molecule. I\n    think the imagination when focused so as to give definition without\n    penumbral haze is sure to realize this image at last.\n\n    To preserve thought continuous throughout this discourse, to prevent\n    either lack of knowledge or failure of memory from producing any\n    rent in our picture, I here propose to run rapidly over a bit of\n    ground which is probably familiar to most of you, but which I am\n    anxious to make familiar to you all.\n\n    The waves generated in the ether by the swinging atoms of luminous\n    bodies are of different lengths and amplitudes. The amplitude is the\n    width of swing of the individual particles of the wave. In water\n    waves it is the hight of the crest above the trough, while the\n    length of the wave is the distance between two consecutive crests.\n    The aggregate of waves emitted by the sun may be broadly divided\n    into two classes, the one class competent, the other incompetent, to\n    excite vision.\n\n    But the light-producing waves differ markedly among themselves in\n    size, form, and force. The length of the largest of these waves is\n    about twice that of the smallest, but the amplitude of the largest\n    is probably a hundred times that of the smallest. Now the force or\n    energy of the wave, which, expressed with reference to sensation,\n    means the intensity of the light, is proportional to the square of\n    the amplitude. Hence the amplitude being one hundred-fold, the\n    energy of the largest light-giving waves would be ten thousand-fold\n    that of the smallest. This is not improbable. I use these figures,\n    not with a view to numerical accuracy, but to give you definite\n    ideas of the differences that probably exist among the light-giving\n    waves. And if we take the whole range of solar radiation into\n    account\u2014its non-visual as well as its visual waves\u2014I think it\n    probable that the force or energy of the largest wave is a million\n    times that of the smallest.\n\n    Turned into their equivalents of sensation, the different light\n    waves produce different colors. Red, for example, is produced by the\n    largest waves, violet by the smallest, while green is produced by a\n    wave of intermediate length and amplitude. On entering from air into\n    more highly refracting substances, such as glass or water or the\n    sulphide of carbon, all the waves are retarded, but the smallest\n    ones most. This furnishes a means of separating the different\n    classes of waves from each other\u2014in other words, of analyzing the\n    light. Sent through a refracting prism, the waves of the sun are\n    turned aside in different degrees from their direct course, the red\n    least, the violet most. They are virtually pulled asunder, and they\n    paint upon a white screen placed to receive them \u201cthe solar\n    spectrum.\u201d\n\n    Strictly speaking, the spectrum embraces an infinity of colors, but\n    the limits of language and of our powers of distinction cause it to\n    be divided into seven segments: Red, orange, yellow, green, blue,\n    indigo, violet. These are the seven primary or prismatic colors.\n    Separately, or mixed in various proportions, the solar waves yield\n    all the colors observed in nature and employed in art. Collectively\n    they give us the impression of whiteness. Pure unsifted solar light\n    is white; and if all the wave constituents of such light be reduced\n    in the same proportion, the light, though diminished in intensity,\n    will still be white. The whiteness of Alpine snow with the sun\n    shining upon it is barely tolerable to the eye. The same snow under\n    an overcast firmament is still white. Such a firmament enfeebles the\n    light by reflection, and when we lift ourselves above a\n    cloud-field\u2014to an Alpine summit, for instance, or to the top of\n    Snowdon\u2014and see, in the proper direction, the sun shining on the\n    clouds, they appear dazzlingly white. Ordinary clouds, in fact,\n    divide the solar light impinging on them into two parts\u2014a reflected\n    part and a transmitted part, in each of which the proportions of\n    wave motion which produce the impression of whiteness are sensibly\n    preserved.\n\n    It will be understood that the conditions of whiteness would fail if\n    all the waves were diminished _equally_, or by the same absolute\n    quantity. They must be reduced _proportionately_ instead of equally.\n    If by the act of reflection the waves of red light are split into\n    exact halves, then, to preserve the light white, the waves of\n    yellow, orange, green, and blue must also be split into exact\n    halves. In short, the reduction must take place, not by absolutely\n    equal quantities, but by equal fractional parts. In white light the\n    preponderance as regards energy of the larger over the smaller waves\n    must always be immense. Were the case otherwise, the physiological\n    correlative, _blue_, of the smaller waves would have the upper hand\n    in our sensations.\n\n    My wish to render our mental images complete, causes me to dwell\n    briefly upon these known points, and the same wish will cause me to\n    linger a little longer among others. But here I am disturbed by my\n    reflections. When I consider the effect of dinner upon the nervous\n    system, and the relation of that system to the intellectual powers I\n    am now invoking; when I remember that the universal experience of\n    mankind has fixed upon certain definite elements of perfection in an\n    after-dinner speech, and when I think how conspicuous by their\n    absence these elements are on the present occasion, the thought is\n    not comforting to a man who wishes to stand well with his\n    fellow-creatures in general, and with the members of the British\n    Association in particular. My condition might well resemble that of\n    the ether, which is scientifically defined as an assemblage of\n    vibrations. And the worst of it is that, unless you reverse the\n    general verdict regarding the effect of dinner, and prove in your\n    own persons that a uniform experience need not continue\n    uniform\u2014which will be a great point gained for some people\u2014these\n    tremors of mine are likely to become more and more painful. But I\n    call to mind the comforting words of an inspired, though uncanonical\n    writer, who admonishes us in the Apocrypha that fear is a bad\n    counsellor. Let me then cast him out, and let me trustfully assume\n    that you will one and all postpone that balmy sleep, of which dinner\n    might, under the circumstances, be regarded as the indissoluble\n    antecedent, and that you will manfully and womanfully prolong your\n    investigations of the ether and its waves into regions which have\n    been hitherto crossed by the pioneers of science alone.\n\n    Not only are the waves of ether reflected by clouds, by solids, and\n    by liquids, but when they pass from light air to dense, or from\n    dense air to light, a portion of the wave motion is always\n    reflected. Now our atmosphere changes continually in density from\n    top to bottom. It will help our conceptions if we regard it as made\n    up of a series of thin concentric layers or shells of air, each\n    shell being of the same density throughout, and a small and sudden\n    change of density occurring in passing from shell to shell. Light\n    would be reflected at the limiting surfaces of all these shells, and\n    their action would be practically the same as that of the real\n    atmosphere.\n\n    And now I would ask your imagination to picture this act of\n    reflection. What must become of the reflected light? The atmospheric\n    layers turn their convex surfaces towards the sun; they are so many\n    convex mirrors of feeble power, and you will immediately perceive\n    that the light regularly reflected from these surfaces cannot reach\n    the earth at all, but is dispersed in space.\n\n    But though the sun\u2019s light is not reflected in this fashion from the\n    \u00e6rial layers to the earth, there is indubitable evidence to show\n    that the light of our firmament is reflected light. Proofs of the\n    most cogent description could be here adduced; but we need only\n    consider that we receive light at the same time from all parts of\n    the hemisphere of heaven. The light of the firmament comes to us\n    across the direction of the solar rays, and even against the\n    direction of the solar rays; and this lateral and opposing rush of\n    wave motion can only be due to the rebound of the waves from the air\n    itself, or from something suspended in the air. It is also evident\n    that, unlike the action of clouds, the solar light is not reflected\n    by the sky in the proportions which produce white. The sky is blue,\n    which indicates a deficiency on the part of the larger waves. In\n    accounting for the color of the sky, the first question suggested by\n    analogy would undoubtedly be, is not the air blue? The blueness of\n    the air has, in fact, been given as a solution of the blueness of\n    the sky. But reason basing itself on observation asks in reply, How,\n    if the air be blue, can the light of sunrise and sunset, which\n    travels through vast distances of air, be yellow, orange, or even\n    red? The passage of the white solar light through a blue medium\n    could by no possibility redden the light. The hypothesis of a blue\n    air is therefore untenable. In fact, the agent, whatever it is,\n    which sends us the light of the sky, exercises in so doing a\n    dichroitic action. The light reflected is blue, the light\n    transmitted is orange or red. A marked distinction is thus exhibited\n    between the matter of the sky and that of an ordinary cloud, which\n    latter exercises no such dichroitic action.\n\n    By the force of imagination and reason combined we may penetrate\n    this mystery also. The cloud takes no note of size on the part of\n    the waves of ether, but reflects them all alike. It exercises no\n    selective action. Now the cause of this may be that the cloud\n    particles are so large in comparison with the size of the waves of\n    ether as to reflect them all indifferently. A broad cliff reflects\n    an Atlantic roller as easily as a ripple produced by a sea bird\u2019s\n    wing; and in the presence of large reflecting surfaces the existing\n    differences of magnitude among the waves of ether may disappear. But\n    supposing the reflecting particles, instead of being very large, to\n    be very small, in comparison with the size of the waves. In this\n    case, instead of the whole wave being fronted and in great part\n    thrown back, a small portion only is shivered off. The great mass of\n    the wave passes over such a particle without reflection. Scatter\n    then, a handful of such minute foreign particles in our atmosphere,\n    and set imagination to watch their action upon the solar waves.\n    Waves of all sizes impinge upon the particles, and you see at every\n    collision a portion of the impinging wave struck off by reflection.\n    All the waves of the spectrum, from the extreme red to the extreme\n    violet, are thus acted upon. But in what proportions will the waves\n    be scattered? A clear picture will enable us to anticipate the\n    experimental answer. Remembering that the red waves are to the blue\n    much in the relation of billows to ripples, let us consider whether\n    those extremely small particles are competent to scatter all the\n    waves in the same proportion. If they be not\u2014and a little reflection\n    will make it clear to you that they are not\u2014the production of color\n    must be an incident of the scattering. Largeness is a thing of\n    relation; and the smaller the wave the greater is the relative size\n    of any particle on which the wave impinges, and the greater also the\n    ratio of the reflected portion to the total wave.\n\n    A pebble placed in the way of the ring-ripples produced by our heavy\n    rain-drops on a tranquil pond will throw back a large fraction of\n    the ripple incident upon it, while the fractional part of a larger\n    wave thrown back by the same pebble might be infinitesimal. Now we\n    have already made it clear to our minds that to preserve the solar\n    light white, its constituent proportions must not be altered; but in\n    the act of division performed by these very small particles we see\n    that the proportions _are_ altered; an undue fraction of the smaller\n    waves is scattered by the particles, and, as a consequence, in the\n    scattered light blue will be the predominant color. The other colors\n    of the spectrum must, to some extent, be associated with the blue.\n    They are not absent, but deficient. We ought, in fact, to have them\n    all, but in diminishing proportions, from the violet to the red.\n\n    We have here presented a case to the imagination, and assuming the\n    undulatory theory to be a reality, we have, I think, fairly reasoned\n    our way to the conclusion that, were particles, small in comparison\n    to the size of the ether waves, sown in our atmosphere, the light\n    scattered by those particles would be exactly such as we observe in\n    our azure skies. When this light is analyzed all the colors of the\n    spectrum are found; but they are found in the proportions indicated\n    by our conclusion.\n\n    Let us now turn our attention to the light which passes unscattered\n    among the particles. How must it be finally affected? By its\n    successive collisions with the particles, the white light is more\n    and more robbed of its shorter waves; it therefore loses more and\n    more of its due proportion of blue. The result may be anticipated.\n    The transmitted light, where short distances are involved, will\n    appear yellowish. But as the sun sinks towards the horizon, the\n    atmospheric distances increase, and consequently the number of the\n    scattering particles. They abstract, in succession, the violet, the\n    indigo, the blue, and even disturb the proportions of green. The\n    transmitted light under such circumstances must pass from yellow\n    through orange to red. This also is exactly what we find in nature.\n    Thus, while the reflected light gives us at noon the deep azure of\n    the Alpine skies, the transmitted light gives us at sunset the warm\n    crimson of the Alpine snows. The phenomena certainly occur _as if_\n    our atmosphere were a medium rendered slightly turbid by the\n    mechanical suspension of exceedingly small foreign particles.\n\n    Here, as before, we encounter our skeptical \u201cas if.\u201d It is one of\n    the parasites of science, ever at hand, and ready to plant itself\n    and sprout, if it can, on the weak points of our philosophy. But a\n    strong constitution defies the parasite, and in our case, as we\n    question the phenomena, probability grows like growing health, until\n    in the end the malady of doubt is completely extirpated.\n\n    The first question that naturally arises is, Can small particles be\n    really proved to act in the manner indicated? No doubt of it. Each\n    one of you can submit the question to an experimental test. Water\n    will not dissolve resin, but spirit will, and when spirit which\n    holds resin in solution is dropped into water the resin immediately\n    separates in solid particles, which render the water milky. The\n    coarseness of this precipitate depends on the quantity of the\n    dissolved resin. You can cause it to separate in thick clots or in\n    exceedingly fine particles. Professor Br\u00fccke has given us the\n    proportions which produce particles particularly suited to our\n    present purpose. One gramme of clean mastic is dissolved in\n    eighty-seven grammes of absolute alcohol, and the transparent\n    solution is allowed to drop into a beaker containing clear water\n    kept briskly stirred. An exceedingly fine precipitate is thus\n    formed, which declares its presence by its action upon light.\n    Placing a dark surface behind the beaker, and permitting the light\n    to fall into it from the top or front, the medium is seen to be\n    distinctly blue. It is not, perhaps, so perfect a blue as I have\n    seen on exceptional days, this year, among the Alps, but it is a\n    very fair sky blue. A trace of soap in water gives a tint of blue.\n    London, and I fear Liverpool milk, makes an approximation to the\n    same color through the operation of the same cause; and Helmholtz\n    has irreverently disclosed the fact that a blue eye is simply a\n    turbid medium.\n\n    Numerous instances of the kind might be cited. The action of turbid\n    media upon light was fully and beautifully illustrated by Goethe,\n    who, though unacquainted with the undulatory theory, was led by his\n    experiments to regard the blue of the firmament as caused by an\n    illuminated turbid medium with the darkness of space behind it. He\n    describes glasses showing a bright yellow by transmitted, and a\n    beautiful blue by reflected light. Professor Stokes, who was\n    probably the first to discern the real nature of the action of small\n    particles on the waves of ether, describes a glass of a similar\n    kind. What artists call \u201cchill\u201d is no doubt an effect of this\n    description. Through the action of minute particles, the browns of a\n    picture often present the appearance of the bloom of a plum. By\n    rubbing the varnish with a silk handkerchief optical continuity is\n    established and the chill disappears.\n\n    Some years ago I witnessed Mr. Hirst experimenting at Zermatt on the\n    turbid water of the Visp, which was charged with the finely divided\n    matter ground down by the glaciers. When kept still for a day or so\n    the grosser matter sank, but the finer matter remained suspended,\n    and gave a distinctly blue tinge to the water. No doubt the blueness\n    of certain Alpine lakes is in part due to this cause. Professor\n    Roscoe has noticed several striking cases of a similar kind. In a\n    very remarkable paper the late Principal Forbes showed that steam\n    issuing from the safety valve of a locomotive, when favorably\n    observed, exhibits at a certain stage of its condensation the colors\n    of the sky. It is blue by reflected light, and orange or red by\n    transmitted light. The effect, as pointed out by Goethe, is to some\n    extent exhibited by peat smoke.\n\n    More than ten years ago I amused myself at Killarney, by observing\n    on a calm day, the straight smoke columns rising from the chimneys\n    of the cabins. It was easy to project the lower portion of a column\n    against a bright cloud. The smoke in the former case was blue, being\n    seen mainly by reflected light; in the latter case it was reddish,\n    being seen mainly by transmitted light. Such smoke was not in\n    exactly the condition to give us the glow of the Alps, but it was a\n    step in this direction. Br\u00fccke\u2019s fine precipitate above referred to\n    looks yellowish by transmitted light, but by duly strengthening the\n    precipitate you may render the white light of noon as ruby colored\n    as the sun when seen through Liverpool smoke or upon Alpine\n    horizons.\n\n    I do not, however, point to the gross smoke arising from coal as an\n    illustration of the action of small particles, because such smoke\n    soon absorbs and destroys the waves of blue instead of sending them\n    to the eyes of the observer.\n\n    These multifarious facts, and numberless others which cannot now be\n    referred to, are explained by reference to the single principle that\n    where the scattering particles are small in comparison to the size\n    of the waves, we have in the reflected light a greater proportion of\n    the smaller waves, and in the transmitted light a greater proportion\n    of the larger waves, than existed in the original white light. The\n    physiological consequence is that in the one light blue is\n    predominant, and in the other light orange or red. And now let us\n    push our inquiries forward. Our best microscopes can readily reveal\n    objects not more than 1/50000 of an inch in diameter. This is less\n    than the length of a wave of red light. Indeed, a first-rate\n    microscope would enable us to discern objects not exceeding in\n    diameter the length of the smallest waves of the visible spectrum.\n    By the microscope, therefore, we can submit our particles to an\n    experimental test. If they are as large as the light-waves they will\n    infallibly be seen; and if they are not seen it is because they are\n    smaller.\n\n    I placed in the hands of our president a bottle containing Br\u00fccke\u2019s\n    particles in greater number and coarseness than those examined by\n    Br\u00fccke himself. The liquid was a milky blue, and Mr. Huxley applied\n    to it his highest microscopic power. He satisfied me at the time\n    that had particles of even 1/100000 of an inch in diameter existed\n    in the liquid they could not have escaped detection. But no\n    particles were seen. Under the microscope the turbid liquid was not\n    to be distinguished from distilled water. Br\u00fccke, I may say, also\n    found the particles to be of ultra microscopic magnitude.\n\n    But we have it in our power to imitate far more closely than we have\n    hitherto done the natural conditions of this problem. We can\n    generate in air, as many of you know, artificial skies, and prove\n    their perfect identity with the natural one as regards the\n    exhibition of a number of wholly unexpected phenomena. By a\n    continuous process of growth, moreover, we are able to connect sky\n    matter, if I may use the term, with molecular matter on the one\n    side, and with molar matter, or matter in sensible masses, on the\n    other.\n\n    In illustration of this, I will take an experiment described by M.\n    Morren, of Marseilles, at the last meeting of the British\n    Association. Sulphur and oxygen combine to form sulphurous acid gas.\n    It is this choking gas that is smelt when a sulphur match is burnt\n    in air. Two atoms of oxygen and one of sulphur constitute the\n    molecule of sulphurous acid. Now it has been recently shown in a\n    great number of instances that waves of ether issuing from a strong\n    source, such as the sun or the electric light, are competent to\n    shake asunder the atoms of gaseous molecules. A chemist would call\n    this \u201cdecomposition\u201d by light; but it behooves us, who are examining\n    the power and function of the imagination, to keep constantly before\n    us the physical images which we hold to underlie our terms.\n    Therefore I say, sharply and definitely, that the components of the\n    molecules of sulphurous acid are shaken asunder by the ether waves.\n    Enclosing the substance in a suitable vessel, placing it in a dark\n    room, and sending through it a powerful beam of light, we at first\n    see nothing; the vessel containing the gas is as empty as a vacuum.\n    Soon, however, along the track of the beam a beautiful sky-blue\n    color is observed, which is due to the liberated particles of\n    sulphur. For a time the blue grows more intense; it then becomes\n    whitish; and from a whitish blue it passes to a more or less perfect\n    white. If the action be continued long enough, we end by filling the\n    tube with a dense cloud of sulphur particles, which by the\n    application of proper means may be rendered visible.\n\n    Here, then, our ether waves untie the bond of chemical affinity, and\n    liberate a body\u2014sulphur\u2014which at ordinary temperatures is a solid,\n    and which therefore soon becomes an object of the senses. We have\n    first of all the free atoms of sulphur, which are both invisible and\n    incompetent to stir the retina sensibly with scattered light. But\n    these atoms gradually coalesce and form particles, which grow larger\n    by continual accretion until after a minute or two they appear as\n    sky matter. In this condition they are invisible themselves, but\n    competent to send an amount of wave motion to the retina sufficient\n    to produce the firmamental blue. The particles continue, or may be\n    caused to continue, in this condition for a considerable time,\n    during which no microscope can cope with them. But they continually\n    grow larger, and pass by insensible gradations into the state of\n    _cloud_, when they can no longer elude the armed eye. Thus, without\n    solution of continuity, we start with matter in the molecule, and\n    end with matter in the mass, sky matter being the middle term of the\n    series of transformations.\n\n    Instead of sulphurous acid we might choose from a dozen other\n    substances, and produce the same effect with any of them. In the\n    case of some\u2014probably in the case of all\u2014it is possible to preserve\n    matter in the skyey condition for fifteen or twenty minutes under\n    the continual operation of the light. During these fifteen or twenty\n    minutes the particles are constantly growing larger, without ever\n    exceeding the size requisite to the production of the celestial\n    blue. Now when two vessels are placed before you, each containing\n    sky matter, it is possible to state with great distinctness which\n    vessel contains the largest particles.\n\n    The eye is very sensitive to differences of light, when, as here,\n    the eye is in comparative darkness, and when the quantities of wave\n    motion thrown against the retina are small. The larger particles\n    declare themselves by the greater whiteness of their scattered\n    light. Call now to mind the observation, or effort at observation,\n    made by our president when he failed to distinguish the particles of\n    resin in Br\u00fccke\u2019s medium, and when you have done so follow me. I\n    permitted a beam of light to act upon a certain vapor. In two\n    minutes the azure appeared, but at the end of fifteen minutes it had\n    not ceased to be azure. After fifteen minutes, for example, its\n    color and some other phenomena pronounced it to be a blue of\n    distinctly smaller particles than those sought for in vain by Mr.\n    Huxley. These particles, as already stated, must have been less than\n    1/100000 of an inch in diameter.\n\n    And now I want you to submit to your imagination the following\n    question: Here are particles which have been growing continually for\n    fifteen minutes, and at the end of that time are demonstrably\n    smaller than those which defied the microscope of Mr. Huxley. What\n    must have been the size of these particles at the beginning of their\n    growth? What notion can you form of the magnitude of such particles?\n    As the distances of stellar space give us simply a bewildering sense\n    of vastness without leaving any distinct impression on the mind, so\n    the magnitudes with which we have here to do impress us with a\n    bewildering sense of smallness. We are dealing with infinitesimals\n    compared with which the test objects of the microscope are literally\n    immense.\n\n    From their perviousness to stellar light, and other considerations,\n    Sir John Herschel drew some startling conclusions regarding the\n    density and weight of comets. You know that these extraordinary and\n    mysterious bodies sometimes throw out tails 100,000,000 of miles in\n    length, and 50,000 miles in diameter. The diameter of our earth is\n    8,000 miles. Both it and the sky, and a good portion of space beyond\n    the sky, would certainly be included in a sphere 10,000 miles\n    across. Let us fill this sphere with cometary matter, and make it\n    our unit of measure. An easy calculation informs us that to produce\n    a comet\u2019s tail of the size just mentioned, about 300,000 such\n    measures would have to be emptied into space. Now suppose the whole\n    of this stuff to be swept together, and suitably compressed, what do\n    you suppose its volume would be? Sir John Herschel would probably\n    tell you that the whole mass might be carted away at a single effort\n    by one of your dray-horses. In fact, I do not know that he would\n    require more than a small fraction of a horse-power to remove the\n    cometary dust. After this you will hardly regard as monstrous a\n    notion I have sometimes entertained concerning the quantity of\n    matter in our sky. Suppose a shell, then, to surround the earth at a\n    hight above the surface which would place it beyond the grosser\n    matter that hangs in the lower regions of the air\u2014say at the hight\n    of the Matterhorn or Mont Blanc. Outside this shell we have the deep\n    blue firmament. Let the atmospheric space beyond the shell be swept\n    clean, and let the sky matter be properly gathered up. What is its\n    probable amount? I have sometimes thought that a lady\u2019s portmanteau\n    would contain it all. I have thought that even a gentleman\u2019s\n    portmanteau\u2014possibly his snuff-box\u2014might take it in. And whether the\n    actual sky be capable of this amount of condensation or not, I\n    entertain no doubt that a sky quite as vast as ours, and as good in\n    appearance, could be formed from a quantity of matter which might be\n    held in the hollow of the hand.\n\n    Small in mass, the vastness in point of number of the particles of\n    our sky may be inferred from the continuity of its light. It is not\n    in broken patches nor at scattered points that the heavenly azure is\n    revealed. To the observer on the summit of Mont Blanc the blue is as\n    uniform and coherent as if it formed the surface of the most\n    close-grained solid. A marble dome would not exhibit a stricter\n    continuity. And Mr. Glaisher will inform you that if our\n    hypothetical shell were lifted to twice the hight of Mont Blanc\n    above the earth\u2019s surface, we should still have the azure overhead.\n    Everywhere through the atmosphere those sky particles are strewn.\n    They fill the Alpine valleys, spreading like a delicate gauze in\n    front of the slopes of pine. They sometimes so swathe the peaks with\n    light as to abolish their definition. This year I have seen the\n    Weisshorn thus dissolved in opalescent air.\n\n    By proper instruments the glare thrown from the sky particles\n    against the retina may be quenched, and then the mountain which it\n    obliterated starts into sudden definition. Its extinction in front\n    of a dark mountain resembles exactly the withdrawal of a veil. It is\n    the light then taking possession of the eye, and not the particles\n    acting as opaque bodies, that interfere with the definition.\n\n    By day this light quenches the stars; even by moonlight it is able\n    to exclude from vision all stars between the fifth and the eleventh\n    magnitude. It may be likened to a noise, and the stellar radiance to\n    a whisper drowned by the noise. What is the nature of the particles\n    which shed this light? On points of controversy I will not here\n    enter, but I may say that De la Rive ascribes the haze of the Alps\n    in fine weather to floating organic germs. Now the possible\n    existence of germs in such profusion has been held up as an\n    absurdity. It has been affirmed that they would darken the air, and\n    on the assumed impossibility of their existence in the requisite\n    numbers, without invasion of the solar light, a powerful argument\n    has been based by believers in spontaneous generation.\n\n    Similar arguments have been used by the opponents of the germ theory\n    of epidemic disease, and both parties have triumphantly challenged\n    an appeal to the microscope and the chemist\u2019s balance to decide the\n    question. Without committing myself in the least to De la Rive\u2019s\n    notion, without offering any objection here to the doctrine of\n    spontaneous generation, without expressing any adherence to the germ\n    theory of disease, I would simply draw attention to the fact that in\n    the atmosphere we have particles which defy both the microscope and\n    the balance, which do not darken the air, and which exist,\n    nevertheless, in multitudes sufficient to reduce to insignificance\n    the Israelitish hyperbole regarding the sands upon the seashore.\n\n    The varying judgments of men on these and other questions may\n    perhaps be, to some extent, accounted for by that doctrine of\n    relativity which plays so important a part in philosophy. This\n    doctrine affirms that the impressions made upon us by any\n    circumstance, or combination of circumstances, depends upon our\n    previous state. Two travelers upon the same peak, the one having\n    ascended to it from the plain, the other having descended to it from\n    a higher elevation, will be differently affected by the scene around\n    them. To the one nature is expanding, to the other it is\n    contracting, and feelings are sure to differ which have two such\n    different antecedent states.\n\n    In our scientific judgments the law of relativity may also play an\n    important part. To two men, one educated in the school of the\n    senses, who has mainly occupied himself with observation, and the\n    other educated in the school of imagination as well, and exercised\n    in the conception of atoms and molecules to which we have so\n    frequently referred, a bit of matter, say 1/50000 of an inch in\n    diameter, will present itself differently. The one descends to it\n    from his molar hights, the other climbs to it from his molecular\n    lowlands. To the one it appears small, to the other large. So also\n    as regards the appreciation of the most minute forms of life\n    revealed by the microscope. To one of these men they naturally\n    appear conterminous with the ultimate particles of matter, and he\n    readily figures the molecules from which they directly spring; with\n    him there is but a step from the atom to the organism. The other\n    discerns numberless organic gradations between both. Compared with\n    his atoms, the smallest vibrios and bacteria of the microscopic\n    field are as behemoth and leviathan.\n\n    The law of relativity may to some extent explain the different\n    attitudes of these two men with regard to the question of\n    spontaneous generation. An amount of evidence which satisfies the\n    one entirely fails to satisfy the other; and while to the one the\n    last bold defense and startling expansion of the doctrine will\n    appear perfectly conclusive, to the other it will present itself as\n    imposing a profitless labor of demolition on subsequent\n    investigators. The proper and possible attitude of these two men is\n    that each of them should work as if it were his aim and object to\n    establish the view entertained by the other.\n\n    I trust, Mr. President, that you\u2014whom untoward circumstances have\n    made a biologist, but who still keep alive your sympathy with that\n    class of inquiries which nature intended you to pursue and\n    adorn\u2014will excuse me to your brethren if I say that some of them\n    seem to form an inadequate estimate of the distance which separates\n    the microscopic from the molecular limit, and that, as a\n    consequence, they sometimes employ a phraseology which is calculated\n    to mislead.\n\n    When, for example, the contents of a cell are described as perfectly\n    homogeneous, as absolutely structureless, because the microscope\n    fails to distinguish any structure, then I think the microscope\n    begins to play a mischievous part. A little consideration will make\n    it plain to all of you that the microscope can have no voice in the\n    real question of germ structure. Distilled water is more perfectly\n    homogeneous than the contents of any possible organic germ. What\n    causes the liquid to cease contracting at 39\u00b0 F., and to grow bigger\n    until it freezes? It is a structural process of which the microscope\n    can take no note, nor is it likely to do so by any conceivable\n    extension of its powers. Place this distilled water in the field of\n    an electro-magnet, and bring a microscope to bear upon it. Will any\n    change be observed when the magnet is excited? Absolutely none; and\n    still profound and complex changes have occurred.\n\n    First of all, the particles of water are rendered diamagnetically\n    polar; and secondly, in virtue of the structure impressed upon it by\n    the magnetic strain of its molecules, the liquid twists a ray of\n    light in a fashion perfectly determinate both as to quantity and\n    direction. It would be immensely interesting to both you and me if\n    one here present, who has brought his brilliant imagination to bear\n    upon this subject, could make us see as he sees the entangled\n    molecular processes involved in the rotation of the plane of\n    polarization by magnetic force. While dealing with this question he\n    lived in a world of matter and of motion to which the microscope has\n    no passport, and in which it can offer no aid. The cases in which\n    similar conditions hold are simply numberless. Have the diamond, the\n    amethyst, and the countless other crystals formed in the\n    laboratories of nature and of man, no structure? Assuredly they\n    have, but what can the microscope make of it? Nothing. It cannot be\n    too distinctly borne in mind that between the microscopic limit and\n    the true molecular limit there is room for infinite permutations and\n    combinations. It is in this region that the poles of the atoms are\n    arranged, that tendency is given to their powers, so that when these\n    poles and powers have free action and proper stimulus in a suitable\n    environment, they determine first the germ and afterwards the\n    complete organism. This first marshaling of the atoms on which all\n    subsequent action depends baffles a keener power than that of the\n    microscope. Through pure excess of complexity, and long before\n    observation can have any voice in the matter, the most highly\n    trained intellect, the most refined and disciplined imagination,\n    retires in bewilderment from the contemplation of the problem. We\n    are struck dumb by an astonishment which no microscope can relieve,\n    doubting not only the power of our instrument, but even whether we\n    ourselves possess the intellectual elements which will ever enable\n    us to grapple with the ultimate structural energies of nature.\n\n    But the speculative faculty, of which imagination forms so large a\n    part, will nevertheless wander into regions where the hope of\n    certainty would seem to be entirely shut out. We think that though\n    the detailed analysis may be, and may ever remain, beyond us,\n    general notions may be attainable. At all events, it is plain that\n    beyond the present outposts of microscopic inquiry lies an immense\n    field for the exercise of the imagination. It is only, however, the\n    privileged spirits who know how to use their liberty without abusing\n    it, who are able to surround imagination by the firm frontiers of\n    reason, that are likely to work with any profit here. But freedom to\n    them is of such paramount importance that, for the sake of securing\n    it, a good deal of wildness on the part of weaker brethren may be\n    overlooked. In more senses than one Mr. Darwin has drawn heavily\n    upon the scientific tolerance of his age. He has drawn heavily upon\n    _time_ in his development of species, and he has drawn adventurously\n    upon _matter_ in his theory of pan-genesis. According to this\n    theory, a germ already microscopic is a world of minor germs. Not\n    only is the organism as a whole wrapped up in the germ, but every\n    organ of the organism has there its special seed.\n\n    This, I say, is an adventurous draft on the power of matter to\n    divide itself and distribute its forces. But, unless we are\n    perfectly sure that he is overstepping the bounds of reason, that he\n    is unwittingly sinning against observed fact or demonstrated law\u2014for\n    a mind like that of Darwin can never sin wittingly against either\n    fact or law\u2014we ought, I think, to be cautious in limiting his\n    intellectual horizon. If there be the least doubt in the matter, it\n    ought to be given in favor of the freedom of such a mind. To it a\n    vast possibility is in itself a dynamic power, though the\n    possibility may never be drawn upon.\n\n    It gives me pleasure to think that the facts and reasonings of this\n    discourse tend rather towards the justification of Mr. Darwin than\n    towards his condemnation, that they tend rather to augment than to\n    diminish the cubic space demanded by this soaring speculator; for\n    they seem to show the perfect competence of matter and force, as\n    regards divisibility and distribution, to bear the heaviest strain\n    that he has hitherto imposed upon them.\n\n    In the case of Mr. Darwin, observation, imagination, and reason\n    combined have run back with wonderful sagacity and success over a\n    certain length of the line of biological succession. Guided by\n    analogy, in his \u201cOrigin of Species\u201d he placed as the root of life a\n    primordial germ, from which he conceived the amazing richness and\n    variety of the life that now is upon the earth\u2019s surface, might be\n    deduced. If this were true it would not be final. The human\n    imagination would infallibly look behind the germ, and inquire into\n    the history of its genesis.\n\n    Certainty is here hopeless, but the materials for an opinion may be\n    attainable. In this dim twilight of speculation the inquirer\n    welcomes every gleam, and seeks to augment his light by indirect\n    incidences. He studies the methods of nature in the ages and the\n    worlds within his reach, in order to shape the course of imagination\n    in the antecedent ages and worlds. And though the certainty\n    possessed by experimental inquiry is here shut out, the imagination\n    is not left entirely without guidance. From the examination of the\n    solar system, Kant and Laplace came to the conclusion that its\n    various bodies once formed parts of the same undislocated mass; that\n    matter in a nebulous form preceded matter in a dense form; that as\n    the ages rolled away heat was wasted, condensation followed, planets\n    were detached, and that finally the chief portion of the fiery cloud\n    reached, by self-compression, the magnitude and density of our sun.\n    The earth itself offers evidence of a fiery origin; and in our day\n    the hypothesis of Kant and Laplace receives the independent\n    countenance of spectrum analysis, which proves the same substances\n    to be common to the earth and sun. Accepting some such view of the\n    construction of our system as probable, a desire immediately arises\n    to connect the present life of our planet with the past. We wish to\n    know something of our remotest ancestry.\n\n    On its first detachment from the central mass, life, as we\n    understand it, could hardly have been present on the earth. How then\n    did it come there? The thing to be encouraged here is a reverent\n    freedom\u2014a freedom preceded by the hard discipline which checks\n    licentiousness in speculation\u2014while the thing to be repressed, both\n    in science and out of it, is dogmatism. And here I am in the hands\n    of the meeting\u2014willing to end, but ready to go on. I have no right\n    to intrude upon you, unasked, the unformed notions which are\n    floating like clouds or gathering to more solid consistency in the\n    modern speculative scientific mind. But if you wish me to speak\n    plainly, honestly, and undisputatiously, I am willing to do so. On\n    the present occasion\n\n                  You are ordained to call, and I to come.\n\n    Two views, then, offer themselves to us. Life was present\n    potentially in matter when in the nebulous form, and was unfolded\n    from it by the way of natural development, or it is a principle\n    inserted into matter at a later date. With regard to the question of\n    time, the views of men have changed remarkably in our day and\n    generation; and I must say as regards courage also, and a manful\n    willingness to engage in open contest, with fair weapons, a great\n    change has also occurred.\n\n    The clergy of England\u2014at all events the clergy of London\u2014have nerve\n    enough to listen to the strongest views which any one amongst us\n    would care to utter; and they invite, if they do not challenge, men\n    of the most decided opinions to state and stand by those opinions in\n    open court. No theory upsets them. Let the most destructive\n    hypothesis be stated only in the language current among gentlemen,\n    and they look it in the face. They forego alike the thunders of\n    heaven and the terrors of the other place, smiting the theory, if\n    they do not like it, with honest secular strength. In fact, the\n    greatest cowards of the present day are not to be found among the\n    clergy, but within the pale of science itself.\n\n    Two or three years ago in an ancient London college\u2014a clerical\n    institution\u2014I heard a very remarkable lecture by a very remarkable\n    man. Three or four hundred clergymen were present at the lecture.\n    The orator began with the civilization of Egypt in the time of\n    Joseph; pointing out that the very perfect organization of the\n    kingdom, and the possession of chariots, in one of which Joseph\n    rode, indicated a long antecedent period of civilization. He then\n    passed on to the mud of the Nile, its rate of augmentation, its\n    present thickness, and the remains of human handiwork found therein;\n    thence to the rocks which bound the Nile valley, and which team with\n    organic remains. Thus, in his own clear and admirable way, he caused\n    the idea of the world\u2019s age to expand itself indefinitely before the\n    mind of his audience, and he contrasted this with the age usually\n    assigned to the world.\n\n    During his discourse he seemed to be swimming against a stream; he\n    manifestly thought that he was opposing a general conviction. He\n    expected resistance; so did I. But it was all a mistake; there was\n    no adverse current, no opposing conviction, no resistance, merely\n    here and there a half humorous but unsuccessful attempt to entangle\n    him in his talk. The meeting agreed with all that had been said\n    regarding the antiquity of the earth and of its life. They had,\n    indeed, known it all long ago, and they good-humoredly rallied the\n    lecturer for coming amongst them with so stale a story. It was quite\n    plain that this large body of clergymen, who were, I should say, the\n    finest samples of their class, had entirely given up the ancient\n    landmarks, and transported the conception of life\u2019s origin to an\n    indefinitely distant past.\n\n    In fact, clergymen, if I might be allowed a parenthesis to say so,\n    have as strong a leaning towards scientific truth as other men, only\n    the resistance to this bent\u2014a resistance due to education\u2014is\n    generally stronger in their case than in others. They do not lack\n    the positive element, namely, the love of truth, but the negative\n    element, the fear of error, preponderates.\n\n    The strength of an electric current is determined by two things\u2014the\n    electro-motive force, and the resistance that force has to overcome.\n    A fraction, with the former as numerator and the latter as\n    denominator, expresses the current-strength. The \u201ccurrent-strength\u201d\n    of the clergy towards science may also be expressed by making the\n    positive element just referred to the numerator, and the negative\n    one the denominator of a fraction. The numerator is not zero nor is\n    it even small, but the denominator is large; and hence the current\n    strength is such as we find it to be. Slowness of conception, even\n    open hostility, may be thus accounted for. They are for the most\n    part errors of judgment, and not sins against truth. To most of us\n    it may appear very simple, but to a few of us it appears\n    transcendently wonderful, that in all classes of society truth\n    should have this power and fascination. From the countless\n    modifications that life has undergone through natural selection and\n    the integration of infinitesimal steps, emerges finally the grand\n    result that the strength of truth is greater than the strength of\n    error, and that we have only to make the truth clear to the world to\n    gain the world to our side. Probably no one wonders more at this\n    result than the propounder of the law of natural selection himself.\n    Reverting to an old acquaintance of ours, it would seem, on purely\n    scientific grounds, as if a Veracity were at the heart of things; as\n    if, after ages of latent working, it had finally unfolded itself in\n    the life of man; as if it were still destined to unfold itself,\n    growing in girth, throwing out stronger branches and thicker leaves,\n    and tending more and more by its overshadowing presence to starve\n    the weeds of error from the intellectual soil.\n\n    But this is parenthetical; and the gist of our present inquiry\n    regarding the introduction of life is this: Does it belong to what\n    we call matter, or is it an independent principle inserted into\n    matter at some suitable epoch\u2014say when the physical conditions\n    become such as to permit of the development of life? Let us put the\n    question with all the reverence due to a faith and culture in which\n    we all were cradled\u2014a faith and culture, moreover, which are the\n    undeniable historic antecedents of our present enlightenment. I say,\n    let us put the question reverently, but let us also put it clearly\n    and definitely.\n\n    There are the strongest grounds for believing that during a certain\n    period of its history the earth was not, nor was it fit to be, the\n    theater of life. Whether this was ever a nebulous period, or merely\n    a molten period, does not much matter; and if we revert to the\n    nebulous condition, it is because the probabilities are really on\n    its side. Our question is this: Did creative energy pause until the\n    nebulous matter had condensed, until the earth had been detached,\n    until the solar fire had so far withdrawn from the earth\u2019s vicinity\n    as to permit a crust to gather round a planet? Did it wait until the\n    air was isolated, until the seas were formed, until evaporation,\n    condensation, and the descent of rain had begun, until the eroding\n    forces of the atmosphere had weathered and decomposed the molten\n    rocks so as to form soils, until the sun\u2019s rays had become so\n    tempered by distance and by waste as to be chemically fit for the\n    decompositions necessary to vegetable life? Having waited through\n    those \u00e6ons until the proper conditions had set in, did it send the\n    fiat forth, \u201cLet life be!\u201d? These questions define a hypothesis not\n    without its difficulties, but the dignity of which was demonstrated\n    by the nobleness of the men whom it sustained.\n\n    Modern scientific thought is called upon to decide between this\n    hypothesis and another; and public thought generally will afterwards\n    be called upon to do the same. You may, however, rest secure in the\n    belief that the hypothesis just sketched can never be stormed, and\n    that it is sure, if it yield at all, to yield to a prolonged siege.\n    To gain new territory, modern argument requires more time than\n    modern arms, though both of them move with greater rapidity than of\n    yore.\n\n    But however the convictions of individuals here and there may be\n    influenced, the process must be slow and secular which commends the\n    rival hypothesis of natural evolution to the public mind. For what\n    are the core and essence of this hypothesis? Strip it naked and you\n    stand face to face with the notion that not alone the more ignoble\n    forms of animalcular or animal life, not alone the nobler forms of\n    the horse and lion, not alone the exquisite and wonderful mechanism\n    of the human body, but that the human mind itself\u2014emotion,\n    intellect, will, and all their phenomena\u2014were once latent in a fiery\n    cloud. Surely the mere statement of such a motion is more than a\n    refutation. But the hypothesis would probably go even further than\n    this. Many who hold it would probably assent to the position that at\n    the present moment all our philosophy, all our poetry, all our\n    science, and all our art\u2014Plato, Shakespeare, Newton, and Raphael\u2014are\n    potential in the fires of the sun.\n\n    We long to learn something of our origin. If the evolution\n    hypothesis be correct, even this unsatisfied yearning must have come\n    to us across the ages which separate the unconscious primeval mist\n    from the consciousness of to-day. I do not think that any holder of\n    the evolution hypothesis would say that I overstate it or overstrain\n    it in any way. I merely strip it of all vagueness, and bring before\n    you, unclothed and unvarnished, the notions by which it must stand\n    or fall.\n\n    Surely these notions represent an absurdity too monstrous to be\n    entertained by any sane mind. Let us, however, give them fair play.\n    Let us steady ourselves in front of the hypothesis, and, dismissing\n    all terror and excitement from our minds, let us look firmly into it\n    with the hard, sharp eye of intellect alone. Why are these notions\n    absurd, and why should sanity reject them? The law of relativity, of\n    which we have previously spoken, may find its application here.\n    These evolution notions are absurd, monstrous, and fit only for the\n    intellectual gibbet in relation to the ideas concerning matter which\n    were drilled into us when young. Spirit and matter have ever been\n    presented to us in the rudest contrast, the one as all noble, the\n    other as all vile. But is this correct? Does it represent what our\n    mightiest spiritual teacher would call the eternal fact of the\n    universe? Upon the answer to this question all depends.\n\n    Supposing, instead of having the foregoing antithesis of spirit and\n    matter presented to our youthful minds, we had been taught to regard\n    them as equally worthy and equally wonderful; to consider them, in\n    fact, as two opposite faces of the self-same mystery. Supposing that\n    in youth we had been impregnated with the notion of the poet Goethe,\n    instead of the notion of the poet Young, looking at matter, not as\n    brute matter, but as \u201cthe living garment of God;\u201d do you not think\n    that under these altered circumstances the law of relativity might\n    have had an outcome different from its present one? Is it not\n    probable that our repugnance to the idea of primeval union between\n    spirit and matter might be considerably abated? Without this total\n    revolution of the notions now prevalent the evolution hypothesis\n    must stand condemned; but in many profoundly thoughtful minds such a\n    revolution has already taken place. They degrade neither member of\n    the mysterious duality referred to; but they exalt one of them from\n    its abasement, and repeal the divorce hitherto existing between\n    both. In substance, if not in words, their position as regards\n    spirit and matter is: \u201cWhat God hath joined together let not man put\n    asunder.\u201d\n\n    I have thus led you to the outer rim of speculative science, for\n    beyond the nebula scientific thought has never ventured hitherto,\n    and have tried to state that which I considered ought, in fairness,\n    to be outspoken. I do not think this evolution hypothesis is to be\n    flouted away contemptuously; I do not think it is to be denounced as\n    wicked. It is to be brought before the bar of disciplined reason,\n    and there justified or condemned. Let us hearken to those who wisely\n    support it, and to those who wisely oppose it; and let us tolerate\n    those, and they are many, who foolishly try to do neither of these\n    things.\n\n    The only thing out of place in the discussion is dogmatism on either\n    side. Fear not the evolution hypothesis. Steady yourselves in its\n    presence upon that faith in the ultimate triumph of truth which was\n    expressed by old Gamaliel when he said: \u201cIf it be of God, ye cannot\n    overthrow it; if it be of man, it will come to naught.\u201d Under the\n    fierce light of scientific inquiry this hypothesis is sure to be\n    dissipated if it possess not a core of truth. Trust me, its\n    existence as an hypothesis in the mind is quite compatible with the\n    simultaneous existence of all those virtues to which the term\n    Christian has been applied. It does not solve\u2014it does not profess to\n    solve\u2014the ultimate mystery untouched. At bottom it does nothing more\n    than \u201ctransport the conception of life\u2019s origin to an indefinitely\n    distant past.\u201d\n\n    For, granting the nebula and its potential life, the question,\n    whence came they? would still remain to baffle and bewilder us. And\n    with regard to the ages of forgetfulness which lie between the\n    conscious life of the nebula and the conscious life of the earth, it\n    is but an extension of that forgetfulness which preceded the birth\n    of us all. Those who hold the doctrine of evolution are by no means\n    ignorant of the uncertainty of their data, and they yield no more to\n    it than a provisional assent. They regard the nebular hypothesis as\n    probable, and in the utter absence of any evidence to prove the act\n    illegal, they extend the method of nature from the present into the\n    past. Here the observed uniformity of nature is their only guide.\n    Within the long range of physical inquiry they have never discerned\n    in nature the insertion of caprice. Throughout this range the laws\n    of physical and intellectual continuity have run side by side.\n    Having thus determined the elements of their curve in this world of\n    observation and experiment, they prolong that curve into an\n    antecedent world, and accept as probable the unbroken sequence of\n    development from the nebula to the present time.\n\n    You never hear the really philosophical defenders of the doctrine of\n    uniformity speaking of _impossibilities_ in nature. They never say,\n    what they are constantly charged with saying, that it is impossible\n    for the builder of the universe to alter His work. Their business is\n    not with the possible, but the actual; not with a world which\n    _might_ be, but with a world which _is_. This they explore with a\n    courage not unmixed with reverence, and according to methods which,\n    like the quality of a tree, are tested by their fruits. They have\n    but one desire\u2014to know the truth. They have but one fear\u2014to believe\n    a lie. And if they know the strength of science, and rely upon it\n    with unswerving trust, they also know the limits beyond which\n    science ceases to be strong. They best know that questions offer\n    themselves to thought which science, as now prosecuted, has not even\n    the tendency to solve. They keep such questions open, and will not\n    tolerate any unlawful limitation of the horizon of their souls. They\n    have as little fellowship with the atheist who says there is no God\n    as with the theist who professes to know the mind of God.\n\n    \u201cTwo things,\u201d said Immanuel Kant, \u201cfill me with awe: the starry\n    heavens and the sense of moral responsibility in man.\u201d And in his\n    hours of health and strength and sanity, when the stroke of action\n    has ceased and the pause of reflection has set in, the scientific\n    investigator finds himself overshadowed by the same awe. Breaking\n    contact with the hampering details of earth, it associates him with\n    a power which gives fulness and tone to his existence, but which he\n    can neither analyze nor comprehend.\n\n\n------------------------------------------------------------------------\n\n\n\n\n    \u25cf Transcriber\u2019s Notes:\n       \u25cb The first 44 footnotes are gathered together in the \u201cNOTES AND\n         REFERENCES\u201d section. The following footnotes appear in the text\n         where they are referenced.\n       \u25cb The mid dot\u2014\u201c\u00b7\u201d is used in numbers to separate the whole part\n         from the decimal fraction of the number.\n       \u25cb Missing or obscured punctuation was silently corrected.\n       \u25cb Typographical errors were silently corrected.\n       \u25cb Inconsistent spelling and hyphenation were made consistent only\n         when a predominant form was found in this book.\n       \u25cb Text that was in italics is enclosed by underscores\n         (_italics_).\n       \u25cb The use of a caret (^) before a letter, or letters, shows that\n         the following letter or letters was intended to be a\n         superscript, as in S^t Bartholomew or 10^{th} Century.\n       \u25cb Superscripts are used to indicate numbers raised to a power. In\n         this plain text document, they are represented by characters\n         like this: \u201cMV^2\u201d or \u201c10^{18}\u201d, i.e. MV squared or 10 to the\n         18th power.","title":"Half Hours With Modern Scientists: Lectures and Essays","tradition":"philosophy-ethics","translated_text":null,"word_count":80328}