{"collection":"philosophy-ethics","full_text_available":true,"graph_url":"https://unchartedknowledge.5gfusion.net/v2/api/page/gutenberg_46078/graph","html_url":"https://unchartedknowledge.5gfusion.net/v2/page/gutenberg_46078","id":"gutenberg_46078","license":"Public Domain (US)","rights_basis":"gutenberg_metadata_copyright_false","source":"gutenberg","source_url":"https://www.gutenberg.org/ebooks/46078","summary":null,"tags":["Category: Philosophy & Ethics","Knowledge, Theory of","Mind and body","Perception","Senses and sensation"],"text":"Transcriber's Notes:\n\n     Italics have been transcribed using _underscores_, small capitals\n     as ALL CAPITALS.\n\n     Depending on the hard- and software used to read this text, not\n     all characters may display properly or at all. The alignment\n     of the tables may depend on the font used.\n\n     Spelling is kept as in the original.\n\n     More Transcriber's Notes may be found at the end of the text.\n\n\n\n\n           THE SENSES\n               AND\n            THE MIND.\n\n\n         _PHILADELPHIA_:\n  AMERICAN SUNDAY-SCHOOL UNION,\n    NO. 146 CHESTNUT STREET.\n\n           _LONDON:_\n    RELIGIOUS TRACT SOCIETY.\n\n\n\n\nNOTE.--The _American Sunday-school Union_ have made an arrangement\nwith the _London Religious Tract Society_, to publish, concurrently\nwith them, such of their valuable works as are best suited to our\ncirculation. In making the selection, reference will be had to the\ngeneral utility of the volumes, and their sound moral tendency. They\nwill occupy a distinct place on our catalogue, and will constitute a\nvaluable addition to our stock of books for family and general reading.\n\nAs they will be, substantially, reprints of the London edition, the\ncredit of their general character will belong to our English brethren\nand not to us; and we may add, that the republication of them, under\nour joint imprint, involves us in no responsibility beyond that of a\njudicious selection. We cheerfully avail ourselves of this arrangement\nfor giving wider influence and value to the labours of a sister\ninstitution so catholic in its character and so efficient in its\noperations as the _London Religious Tract Society_.\n\n\u261e The present volume is issued under the above arrangement.\n\n\n\n\nCONTENTS.\n\n\n                                                       Page\n  CHAPTER I.                                              5\n\nON THE GENERAL RELATIONSHIP OF MAN TO THE WORLD AROUND HIM,\nAND HIS ADAPTATION TO THE PLANET HE TENANTS\n\n\n  CHAPTER II.                                             45\n\nMAN'S KNOWLEDGE OF THE QUALITIES OF MATTER OBTAINED THROUGH\nTHE MEDIUM OF THE SENSES\n\n\n  CHAPTER III.                                            69\n\nTHE SENSES, AS THE INLETS TO KNOWLEDGE--SIGHT AND HEARING\n\n\n  CHAPTER IV.                                            153\n\nOBSERVATIONS ON THE AGENCY OF THE SENSES, RELATIVE TO\nTHE UNION BETWEEN MIND AND MATTER; AND ON THE OCCASIONAL\nIMPERFECTION OF THE BODILY ORGANS OF THE SENSES, WITH THE\nRESULTS DEPENDING THEREUPON\n\n\n\n\nTHE SENSES AND THE MIND.\n\n\n\n\nCHAPTER I.\n\n     ON THE GENERAL RELATIONSHIP OF MAN TO THE WORLD AROUND HIM, AND\n     HIS ADAPTATION TO THE PLANET HE TENANTS.\n\n\nThere are few, at least among the reflecting portion of society,\nwho have not either mentally or verbally asked the question: Is the\nsun--is the moon--are the planets, with their satellites--are the\nstars, those suns of other systems, tenanted, as is our planet, the\nearth, by living beings, which declare the omnipotence of God? This\nis one of many questions which cannot be answered. The probability,\nto judge from analogy, is, that some, if not all, are inhabited;\nthat some are in a course of preparation for beings which God will,\nin his own time, call into existence; and that in all, changes have\ntaken place more or less similar to those which have occurred on the\nglobe we tenant, and which have been connected with the extinction of\nraces, and the creation of others adapted and organized for an altered\ncondition of the earth's surface, and of the circumambient atmosphere.\nBut, granting these suppositions, it must be evident, that the living\nbeings in the sun, the planets, and the asteroids, must not only be\ndifferently constructed from those which inhabit our planet, the earth;\nbut, also, that in different worlds, the living inhabitants must be\nvery diversely constituted, not only as regards their senses, but also\ntheir organization and their powers of locomotion.\n\nWe cannot conceive of beings unlike ourselves, and the animals,\nterrestrial and aquatic, which, called into existence by Almighty\nPower, people the surface of our earth; that, however, is no reason\nwhy such beings should not exist, for what is impossible with God?\nNay, as it is, the senses, the operations, the powers, and economy\nof insects confound us, and lead us to suspect that they possess a\nsense, or senses, which, because denied to us, we cannot appreciate. In\nour world, atmospheric air, in which oxygen prevails, or water, also\noxygenated, is essential to the maintenance of animal life. But cannot\nthe Almighty construct organic beings, independent of our air or our\nwater--vitalized, in fact, on principles of which we can form no idea?\nUndoubtedly. If, for example, no aquatic water-breathing animals, as\nfishes, crustacea, etc., existed on our earth, could we conceive of the\npossibility of their being? or, were our race, and all other animals\nfurnished with gills instead of lungs, and ordained to a sub-aquatic\nlife, making the wide ocean our home, could we form any idea of what\ncreatures could be constituted for living in the thin atmosphere, and\nactively enjoying life under its pressure? Again, let the attractive\nforce of this earth be altered, the organization of every living thing\nmust (granting its existence to be guaranteed) be altered accordingly.\nWe take the following from Miss Somerville's \"Connexion of the Physical\nSciences,\" p. 73:--\"The densities of bodies are proportional to their\nmasses, divided by their volumes. Hence, if the sun and planets be\nassumed to be spheres, their volumes will be as the cubes of their\ndiameters. Now, the apparent diameters of the sun and earth, at their\nmean distance, are 1922\u2033, 8, and 17\u2033, 1552, and the mass of the earth\nis the 354,936th part of that of the sun, taken as the unit. It\nfollows, therefore, that the earth is nearly four times as dense as\nthe sun; but the sun is so large that his attractive force would cause\nbodies to fall through about 335 feet in 1\u2033; consequently, if inhabited\nby human beings, they would be unable to move, since their weight would\nbe thirty times as great as it is here.\" A man of moderate size would\nweigh about two tons at the surface of the sun; whereas, at the surface\nof the asteroids, (the clusters between Mars and Jupiter,) he would be\nso light that he could not stand steadily, since he would only weigh a\nfew pounds.\n\nThe densities, that of water being 1, as far as can be satisfactorily\nexplained, are as follow:--Sun, 1-2/15; Mercury, 9-1/6; Venus,\n5-11/15; Moon, 4-1/2; Mars, 3-2/7; Ceres, 2; Pallas, 2; Jupiter,\n1-1/24; Saturn, 13/32; Herschel, 99/100.\n\nSimilar observations apply to the influence of the atmosphere, in\nwhatever point of view we consider it, that is, whether we regard its\nweight, its electrical condition, its illumination, its temperature,\nits dryness, or humidity.\n\n1. _Its Weight._--The weight of the atmosphere (an elastic,\ncompressible, and expansible fluid,) is calculated to be from fourteen\nto fifteen pounds avoirdupois on every square inch, (pure water,\ntaking bulk for bulk, being about 828 times as heavy.) Now, reckoning\nthe surface of a middle-sized man to be fourteen feet, he sustains\nthe pressure of eleven tons. Many of our readers have seen the\nphilosophical experiment of placing two hollow metallic hemispheres\nrim to rim, the rims being nicely adjusted and smeared with lard;\nthis being done, the air, by means of a stop-cock on the lower\nhemisphere, screwed into a powerful air-pump apparatus, is drawn out\nor exhausted--the stop-cock is turned--the globe is unscrewed from the\nair-pump, and placed in the hands of those who may consent to try their\nstrength in pulling the two hemispheres asunder. Enormous is the force\nrequired; if the diameter of the circle be fourteen inches, the least\nforce that will separate them will be equivalent to half a ton.\n\nSuch, then, being the pressure of the atmosphere, as is clearly proved\nby simple experiments, it may at first create some surprise that the\nhuman body is capable of sustaining it without being crushed; that\nthe tiny insect, with its delicate wings--and in some these amount to\nseveral square inches of surface--is not reduced to atoms. But the\nwonder will cease, when we reflect that this pressure, or a pressure\nlittle short of it, is essential to the existence, not of man only, but\nof all terrestrial organic beings.\n\nDr. Robinson justly observes, that \"the human body (he might have said\nevery organic body) is a bundle of solids mixed with fluids, and there\nare few or no parts of it which are empty. All communicate either by\nvessels or by pores, and the entire surface is a sieve, through which\nthe insensible perspiration is performed. The whole extended surface\nof the lungs is open to the pressure of the atmosphere; everything,\ntherefore, is in equilibrio; and if free or speedy access be given\nto every part, the body will not be damaged by the pressure, however\ngreat, any more than a wet sponge would be deranged by pressing it to\nany depth in the water.\"[1]\n\n[1] Mechanical Philosophy, vol. iii. p. 54.\n\nOn this we would remark, that the human body, and that of terrestrial\nanimals in general, is not adapted for the pressure of water at great\ndepths; even could man by any contrivance breathe, such a pressure\nwould destroy life; and, indeed, few aquatic animals are constituted\nfor oceanic existence in the depths of the sea. While the surface is\nalive with its myriads, the depths are still and untenanted; while\nbays, shores, reefs, and sandbanks, covered by many fathoms of water,\nare teeming with shelled mollusks, fishes, and thousands of wondrous\ncreeping things, the profundity of ocean is a comparative desert;\nwhatever lives there must be so constituted as to sustain a tremendous\namount of aqueous pressure. Indeed, whales, which often plunge to a\nconsiderable depth, and remain submerged for twenty minutes, during\nwhich time respiration is suspended, are provided by their coating of\nblubber, and by the peculiar arrangement of their arterial and venous\nsystems, for the pressure they then undergo; but this pressure often\nrepeated, as it is when the animal is wounded and hard driven, soon\nproduces great exhaustion. Captain Scoresby, for example, harpooned a\nwhale, which, on receiving the weapon, descended four hundred fathoms,\nat the rate of eight miles an hour; but these animals, when suffering\nfrom the torture of the harpoon, often descend to a much greater depth,\nand sometimes strike so violently against a hard bed of the ocean as\nto fracture their jaws. At the depth of eight hundred fathoms, captain\nScoresby calculates the pressure at 211,200 tons. On the other hand,\nthe organization of man (and other animals) is as ill calculated for a\nmuch lighter pressure than that of our atmosphere at sea-level, as it\nis for great pressure in the depths of ocean.\n\nIn proportion as we ascend the alpine elevations of our globe, or\nmount upwards in a balloon, we find the air more and more rarefied.\nThese elevations are, however, but trifling; nevertheless, trifling\nas they are, what an effect the decrease of pressure produces on the\nhuman frame! The heart beats with violence, the lungs gasp for more\nair, they have not pressure enough; the blood begins to ooze out of the\nminute vessels ramifying through the tissue of their delicate cells;\nblood issues from the nose, the eyes, the ears; the slightest exertion\nbecomes oppressive--a mile or two higher, and death is inevitable. The\ndifficulties attendant upon the ascent of Mont Blanc, the vast Himalaya\nchain, and the heights of the Cordilleras, are quite as much connected\nwith the state of the air as with the terrible ravines and precipices\nwhich obstruct the way. Indeed, as is well known, on the elevated\nplateaus of South America or Thibet, men and animals accustomed to\nlow plains, or even to gently undulating grounds, are for a long time\ndistressed for breath, and incapable of bodily exertion. Time alone\nhabituates them to the rarer and lighter atmosphere. But what is an\nelevation of 13,000 or 14,000 feet, nay of 15,668 feet, (Mont Blanc,)\nof 25,747 feet, or 28,077 feet, (Jewahir and Dhawalagiri, peaks of the\nHimalaya,) to that of twenty or thirty miles? At an elevation of twenty\nmiles, the heart of a human being would burst, his lungs become gorged\nwith blood, from every pore of his body a sanguine stream would gush\nforth--he would immediately die. Is not, then, the pressure of the\natmosphere necessary for the existence of man, constituted as he is for\nthe planet which he inhabits? But the atmosphere, with regard to its\nrelationship to the solid globe it environs, demands a few words.\n\nThis elastic fluid must be considered as a body of air revolving with\nthe earth, whence it must be evident that the velocity of the strata of\nair, if we may use the word, increases as we recede from the earth's\naxis; for example, at the equator, that stratum of air, (if such there\nbe,) which is twice as distant from the centre of the earth as the\nsurface is, must revolve with twice the actual velocity of the air at\nthe surface. Taking this fact into consideration, it results that,\nhowever attenuated, however rarefied, the atmosphere cannot extend\nbeyond 20,000 miles from the surface of the earth; far above that\nelevation the centrifugal force would counteract the centripetal,\nor, in other words, the tendency of the particles to the earth would\ncease, and, consequently, unless air pervaded the universe, which is\nnot the case, 20,000 miles are within the utmost range of possibility.\nThe fact, however, appears to be demonstrated, that the limits of our\natmosphere do not exceed an elevation of above forty-five or fifty\nmiles, and that beyond this there is no refraction or reflection of\nthe solar rays--that, in fact, air ceases. The finite extent of the\natmosphere has been ably discussed by Dr. Wollaston,[2] his arguments\nbeing based upon the _Atomic Theory_ of matter. We may thus condense\nhis train of reasoning, as far as it bears more immediately upon the\npresent subject.--If air extend throughout the universe, we shall be\nobliged to admit that every planet must collect an atmosphere around\nitself proportionate to its attractive power. In this case, as he\nargues, Jupiter, at whose surface the force of gravity must be much\ngreater than that of our earth, would certainly collect a large and\ndense atmosphere around him. The effect of the refraction of light\nthrough this atmosphere would become visible on the approach of the\nsatellites to the planet, when they disappear behind his disc, and\nwould cause a sensible retardation in their rate of approach. Now, it\nis allowed that no such retardation, even in the minutest sensible\ndegree, can be observed, and hence it follows that Jupiter has no\nsuch atmosphere as that of our earth, nor the means of collecting\nit; consequently, air, such as that composing our atmosphere, is not\ndiffused in any degree of rarefaction through the solar system. This\nfinite character of our atmosphere is, as Dr. Wollaston contends,\nmore conformable to the atomic theory than to that of the infinite\ndivisibility of matter; since, in the first case, a boundary is\npossible, and will exist at the point where the weight of a single atom\nis as great as the repulsive force of the medium; while, in the latter\ncase, it is difficult to see the possibility of any boundary.\n\n[2] Phil. Trans., 1822.\n\nBy way of note we would here add, that the theory of the _infinite_\ndivisibility of matter, which all the laws of chemistry seem to deny,\nhas no good grounds for our acceptance. God made matter, and, as we\nmay humbly conceive, in the form of ultimate atoms, which, however\ninconceivably minute, must be definite--otherwise what is meant by\ncreation? That which is created must have definite figure, size, etc.,\nelse it is nothing; and to talk of a creation where size of figures\nis absent, is absurd. We know that atheistical philosophers advocate\nthe theory of the infinite divisibility, and infinite, essentially\ninfinite duration of matter, for these points are steps to the theory\nof non-creation, or rather involve it. Infinite duration, infinite\ndivisibility, infinite extension, and the plastic power of infinite\ntime, together with the innate, ungiven laws of this infinite matter,\nform the key-stones to their unholy temple entrance. On this theory,\nworlds formed themselves, and harmonized with each other; living\nmicroscopic monads called themselves into being, and by voluntary\nexertion became developed through various phases into man. Thus, then,\nhe owes no Creator thanks! Impious, irrational, debasing doctrine!\n\nSupposing, then, that our atmosphere is not continued to an altitude\nexceeding fifty miles, forming a sort of circumambient ocean, at\nthe bottom of which we live, and which is created for our peculiar\norganization, still it is not altogether improbable that some subtle\nethereal fluid, altogether different from our atmosphere, may extend\nitself throughout space--a fluid of extreme attenuation, the nature of\nwhich is to us unknown in fact--a fluid so impalpable as to cause no\nsensible retardation to the rate of motion in the planets.\n\nWe do not positively assert that such a subtle fluid exists, though\nmany astronomers are in favour of this hypothesis; and, indeed, we\nbelieve that Encke's comet appears in successive revolutions to show\nin some slight degree the effect of some medium resisting its motion,\nand that the same observation applies to the comet of Biela. But when\nwe consider the great tenuity of the substance of these comets, through\nwhich even faint stars may be seen, we shall be justified in regarding\nthis resisting medium as being more subtle, attenuated, and elastic,\nthan can be well expressed in words.\n\nTo revert now to our atmosphere, there is another interesting point\nwhich requires our notice; namely, are the constituents of this\natmosphere chemically united together, or only simply mixed in certain\nproportions? We believe that it consists of a simple mixture only of\ntwo essential gases, or elements, namely, oxygen and nitrogen, with\na small and variable quantity of carbonic acid, and also with water\nin a state of vapour. We may consider the last two as accidental\ningredients, essential as the vapour of the atmosphere may be to the\nnecessities of animals and plants, to luxuriance of scenery, and\nfertility of soil. The essentials of air are united in the following\nproportions, namely, one part of oxygen and two of nitrogen, or one\natom of oxygen and two atoms of nitrogen; but as the atomic weights\nof oxygen are as 8 to 14, the proportion of the weights of the two in\nany given quantity of air will be that of 8 to 28, or two to seven; in\nother words, nine grains by weight of air will contain two grains of\noxygen, and seven of nitrogen, supposing the air to be pure.\n\nBut, as we have said, a portion of carbonic acid gas is usually\ncontained in air; this gas is exhaled from the earth, and collects in\ncertain localities, rendering the air more impure than it otherwise\nwould be; as a rule, however, the quantity of this gas in intermixture\nwith the air we breathe--its lower strata--varies from three to eight\nparts out of a thousand in weight; in its pure state, it is immediately\ndestructive to animal life; but thus diluted is in this respect\ninnoxious, while to the vegetable kingdom it is necessary. With respect\nto water in a state of viewless vapour, the quantum in any given weight\nof air seldom exceeds 1-1/2 per cent.\n\nNow if, as most philosophers of the present day seem to consider, there\nis no chemical union of the gases constituting the atmosphere, it may\nbe supposed that, according to their respective weights, a partial\nseparation and subsidence of the heavier will take place, while the\nlighter will chiefly compose the upper portion--thus, for example,\na stratum of nitrogen will surmount a stratum of mixed nitrogen and\noxygen, and this a stratum of mixed nitrogen, oxygen, and carbonic\nacid. The following passage from the Penny Magazine will illustrate\nthis theory: \"A law is found to prevail in the mixture of gases and\nvapours, as universal as is that relative to their expansion arising\nfrom temperature, namely, that two gases in a state of mixture exercise\nno influence one upon the other, except communication of temperature,\nbut that each is disposed in exactly the same way as it would be if\nthe other were not present. Thus it is found, entirely contrary to\nall previous notions, that no pressure of dry air upon water exerts\nthe least influence in preventing the formation of steam, which goes\non exactly as if the space above were a vacuum, and continues until\nfurther evaporation is stopped by the pressure of the steam already\ncreated. It is found that no pressure of one gas can confine another\nin water; but that, supposing a bottle partly full of water, the gas\nconfined in the water will escape to the surface, and distribute itself\nin precisely the same way as if the other gas were not present. By this\nit is not meant that the action, commonly called mechanical, cannot\ntake place, or that a stream of hydrogen would not trouble the air;\nbut only that the permanent settlement of one gas is not affected in\nany way by the presence of another, so long as no chemical action is\nexcited.\n\n\"From this principle, Mr. Dalton,[3] taking into consideration the\npresumptions which exist against the chemical union of the ingredients\nof the atmosphere, infers, that the atmosphere does not altogether\nconsist of the compound called air, but that the nitrogen atmosphere\nis higher than the oxygen atmosphere. In fact, if there be no chemical\nunion, the above law of the mixture of gases requires us to allow that\neach is an atmosphere independent of the other, and that the two are\nmost probably of unequal heights. From some considerations into which\nwe cannot here enter, Mr. Dalton thinks that the actual pressures\nexerted by the oxygen and nitrogen are in the proportions of the\nvolumes occupied by them, that is, as one to four; and concludes that\nthe oxygen atmosphere extends to thirty-eight miles in height, that of\nnitrogen to fifty-four miles, that of carbonic acid to ten miles, and\nthat of aqueous vapour to fifty miles. It must be observed, however,\nthat the state of the carbonic acid of the atmosphere is very variable;\nthat there is not the same quantity by night as by day, in moist\nweather as in dry; and that the higher strata of the atmosphere contain\nmore of it than the lower, which may arise from a rapid absorption by\nthe earth.\n\n\"Against the hypothesis just described, it might, perhaps, be asserted,\nthat the air which Gay-Lussac brought down from a height of more than\nfour miles was not found to differ from that of the earth's surface in\nthe proportion of its oxygen to its nitrogen, which would be the case\nif the oxygen atmosphere diminished in density more than in proportion\nto the diminution of that of the nitrogen, or _vice vers\u00e2_.\"\n\n[3] Phil. Trans., 1826.\n\nWithout attempting to settle the question as to whether the component\nparts of the air are in a state of chemical union, or only in a state\nof simple mixture, of this we are sure, that the air is essential to\nthe existence of all organic beings which live on the surface of our\nplanet, that is to animals and plants, though the relationship of each\nto the air is diverse. The following comparison between the two great\ngroups of organic creation, which we copy from an admirable paper on\nthe Progress of Organic Chemistry in the \"Companion to the Almanack,\n1849,\" shows the respective relationships of animals and plants to the\nelements around them, as well as their mutual balance and dependence:--\n\n  An Animal is an Apparatus       A Vegetable is an Apparatus\n       of Combustion.                 of Reduction.\n  _Burns_      Carbon             _Reduces_     Carbon\n       \"       Hydrogen               \"         Hydrogen\n       \"       Ammonium.              \"         Ammonium.\n  _Exhales_    Carbonic Acid      _Fixes_       Carbonic Acid\n       \"       Water                  \"         Water\n       \"       Oxide of Ammonium      \"         Oxide of Ammonium\n       \"       Nitrogen, or           \"         Nitrogen, or\n                 Azote.                           Azote.\n  _Consumes_   Oxygen             _Produces_    Oxygen\n       \"       Proteine               \"         Proteine\n       \"       Fats                   \"         Fats\n       \"       Starch                 \"         Starch\n       \"       Sugar                  \"         Sugar\n       \"       Gum.                   \"         Gum.\n  _Produces_   Heat               _Absorbs_     Heat.\n       \"       Electricity.       _Abstracts_   Electricity.\n  _Restores_   Its elements to    _Derives_     Its elements\n                 the air or                       from the air or\n                 earth.                           from the earth.\n  _Transforms Organized_ matter   _Transforms Mineral_ matter\n                 into _mineral_                   into _organic_\n                 matter.                          matter.\n\nIs not the wisdom of God here manifest?--The vegetable kingdom is made\nauxiliary to the animal, and _vice vers\u00e2_.--Yet, how? by mysterious\nchanges, appropriations, productions, and consumptions, upon which\nmodern researches are from time to time throwing new light; or, in\nother words, unfolding to us new revelations of the power and wisdom\nof the Great Eternal, who has condescended to give us a _spiritual_\ndirectory, a guide to our feet, and a lamp to our path, by means of\nwhich we, who at best only see through a glass darkly, may be led\ninto that glorious world where there are no clouds--where there is no\nnight--where there is \"no need of the sun, neither of the moon, to\nshine in it: for the glory of God\" doth \"lighten it, and the Lamb is\nthe light thereof.\"\n\n2. _Its Electrical Condition._--With the electrical changes in the\nstate of the atmosphere are connected various transitions from heat\nto cold, dew, rain, hail, snow, clouds, winds, thunder-storms, auror\u00e6\nboreales, haloes, parhelia, etc. In this point of consideration the\natmosphere bears upon organic life. The solid globe itself may be\nregarded as a vast electrical or galvanic apparatus, and all the vital\nfunctions of animal bodies involve electric or galvanic phenomena.\nMagnetism appears to be essentially identical with electricity;\nboth are most intimately connected with light and heat; and not\nonly electric sparks, but all the phenomena of electricity, can be\nobtained from a common magnet. It is not here our purpose to enter\ninto a philosophical treatise on electricity and galvanism; a little\nconsideration, however, will lead us to infer that the general\ndiffusion of this subtle electric fluid, if the term fluid be at all\napplicable, is essential to the maintenance of organic life, and that\nelectrical changes are perpetually taking place in organic bodies.\nThis fluid is derived from the earth, or its circumambient atmosphere,\nand its currents obey definite laws, which have been elucidated by the\nexperiments of some of the most profound philosophers of modern times.\n\nAfter what we have briefly said respecting the electric condition of\nour globe, and the electrical phenomena which are involved in the\nprocesses of the vital functions, to say nothing of electro-magnetism,\nit must surely be apparent, that even as the air is in itself necessary\nto our existence, so the diffusion of that subtle matter, now quick,\nnow slowly acting, now energetic, and now darting from the clouds\nto the solid earth a vivid flash, creating a momentary light in\ndarkness--is equally essential; this is a point which, by the world at\nlarge, is but slightly taken into consideration. Remove this subtle\nelement from the earth, and what would be the result? Perhaps the globe\nwould deviate from her course; perhaps an alteration in her polar axis\nwould take place. Perhaps--but why enter into such speculations? This\nis certain--animal and vegetable life, as at present constituted, could\nnot exist: but all is ordered aright; the organization of matter,\nand the senses of living beings, are involved in the presence of an\nelement, variable, it may be, in its phases, but mighty in its effects.\nHere animals and plants play their part transversely, for each other's\nbenefit; animals produce electricity, by means of the vital operations\nof their organization, and this produce, given to the earth and air,\nis abstracted by plants. They antagonize each other, and the result is\nharmony.\n\n3. _Its Illumination._--Light is evolved by and during the combustion\nof various bodies, as wood, coal, tallow, and spirits, or alcoholic\nfluids; it is the result of electricity--that is, of the electric spark\nor flash; it is evolved during many chemical experiments, and by the\nattrition of two quartz pebbles. The percussion of flint and steel\nproduces luminous sparks; these sparks consisting, as the experiments\nof Mr. R. Hook have proved, of minute ignited globules of iron, struck\noff at the moment of percussion. These, and many other sources whence\nlight proceeds, need not here be detailed; our object is with that\ngeneral light, the light of day, which results from the influence of\nthe solar rays. For the reception of pictures on the retina by means\nof the rays of light reflected from all things within the scope of\nvision, the eyes of animals are especially constructed. To some animals\na dim twilight suffices, so far as regards their personal maintenance\nand their enjoyment of life; to a few the little light, which even\nin the darkest night is not absent, is all that is required for\ntheir ordained habits and economy. In such instances, the retina is\nexquisitely susceptible, and the iris dilates to admit the entrance\nof every feeble ray reflected from the objects either of their search\nor avoidance. Often have we seen the owl, when twilight has melted\ninto darkness, skimming over the fields, along the lane, and around\nthe barn, quartering the ground in search of mice or moles, which, had\nthey been at our feet, would to our eyes have been invisible. On the\nother hand, they would have been nearly, if not quite invisible to\nthe owl in the full glare of sunshine. Yet, be it understood, light\nis as essential to the night-bird as to men, or the giraffe of the\nglowing wilds of Africa. We know not what _total darkness_ is, unless\nperhaps we be walled up in a deep dungeon underground, to which light\nis utterly denied access; such living tombs have been contrived by\nthe diabolical minds of tyrants, pagan and papistical. In the darkest\nnight, even our eyes dimly discern the \"form of things obscure\"--things\nwhich, to a nocturnal animal, would be boldly conspicuous.\n\nLight is a stimulus both to the animal and vegetable worlds. It is\nwhen daylight breaks that \"man goeth forth unto his work and to his\nlabour until the evening;\" it is when light breaks that the feathered\nsongsters of the grove join in one chorus of--why may we not say\nso?--instinct-urged thanksgiving. O man, gifted with reason! O man, the\nheir of immortality! utter, then, thy song of praise, of gratitude,\nthat the light of another day is bestowed upon thee: and then be\ndiligent in all that God has called upon thee to perform, seeing that\n\"the night cometh, when no man can work.\"\n\nLight is a stimulus, more or less grateful to every living creature.\nReader, have you ever wandered along the sea-shore, and explored the\nmasses of rock left uncovered when the tide is fully out; there,\nadhering to the surface of the stone, in little ponds, mimic bays, may\nbe seen scores of sea-anemonies (_actinia_.) If the sky be bright,\nthere will they be, with their painted tentacles all expanded, animal\nflowerets feeling the influence of light; but let the sky change, let\nclouds obscure the day, and they retract their tentacles and shrink\ninto repose. These animals have no eyes, but yet they are sentient of\nlight. We mention these sea-anemonies merely by way of example; other\neyeless, and we may say, apparently nerveless creatures evidently enjoy\nthe influence of light, as the hydra, the medusa, and the polyps of\ncorals.\n\nIf light waken up some animals from their repose--if it rouse the cock,\nand bid him sound his \"clarion shrill,\" it warns others to retire to\ntheir obscure dormitory, and slumber till twilight recalls them into\nactivity. The moth now flits abroad, and the bat and the fern-owl are\non the wing, giving chase to their insect prey. The hedgehog is all\nalert, searching for slugs, worms, and various creeping things, which\nrevel in the dews of sunset. It is then, too, that the fierce prowlers\nof the forest issue from their lair, eager for blood; but when \"the sun\nariseth, they gather themselves together, and lay them down in their\ndens.\"\n\nLight is not only a stimulus to animals, in the sense above noticed; it\nappears to be essential to health and vigour. Of this we are the less\naware, because, under ordinary circumstances, we are always subject\nto its influence. Men have been confined for years in dark dungeons,\nand have reappeared upon the stage of life, pallid, meagre, weak, and\nemaciated beings, like breathing corpses; confinement, bad food, ill\nventilation, and mental agony, had no doubt done their work; but want\nof light also had part in the sad devastation of the animal frame.\nLook, for example, at those parts of our bodies which are usually\nclothed, and compare the colour of the skin with that of the hands\nand face; strip the arm bare--the skin is acted upon by atmospheric\nair, but yet how much whiter than that of the hand, delicate as that\nhand may be. It may be said that heat, that is, solar heat, produces\nthe difference. Partly so, no doubt, but not altogether. The face and\nhands of the Esquimaux are darker than his chest; moreover, suppose a\nsevere and extensive cut happens, and that the wound thus inflicted\nis bound up for weeks by adhesive plaster, what do we see on removal\nof the straps and bandages?--a singular whiteness of the skin, the\nresult, as it appears to us, of the exclusion of light from the\ncovered portion. Plants, as all must have noticed, have their leaves\nand flowers drawn towards the light, and become pallid when kept in\ndark places. Thus, for example, some flowers open only when the sky is\nclear, as the little pimpernel, the index of fair weather; others, as\nthe sunflower, turn to the sun in his course from east to west; the\neyes, or germinating stalk of the potato, though they shoot vigorously\nin the dark, are blanched; so are the covered leaves of endive, and\nthe covered stalks of celery and sea-kale. Light is a chemical agent;\nlight, as the apothecary well knows, greatly impairs the activity of\nthe dried and powdered leaves of foxglove, and blanches castor oil.\nLight, therefore, is found to effect both chemical combination and\nchemical decomposition.\n\nIn nothing, perhaps, is the chemical agency of light more clearly\nshown than in the photogenic drawings, which are the fac-simile\nrepresentations of objects delineated by the action of light on a thin\nsensitive layer of ioduret of silver. The following is the mode of\npreparing the plates for the reception of photogenic drawings, given\nin the Penny Cyclop\u00e6dia:--These drawings \"are produced on plates of\ncopper, coated over with silver, which are found to answer better than\nsuch as are entirely of the last-mentioned metal. After being washed\nwith a solution of nitric acid, the plate is put into a well-closed\nbox, where it is exposed to the action of iodine, a small quantity of\nthe latter being placed at the bottom of the box, with a thin gauze\nbetween it and the plate. A layer of ioduret of silver is thus formed\non the surface of the plate, and manifests itself by the yellow hue\nproduced on the silver, which shows that the process of giving the\nplate the sensitive coating on which the action of the light delineates\nobjects is completed. Thus prepared, the plate is placed within a\ncamera obscura, of particular construction, and the delineation of\nthe object is then effected in a very short space of time; but has to\nbe afterwards brought out and rendered distinct by another operation,\nnamely, submitting the plate to the action of vapour of mercury. Even\nthen the process is not completed, for the plate has to be plunged into\na solution of hyposulphate of soda, and afterwards washed in distilled\nwater, which being done, the impression is fixed, and the plate may be\nexposed to light with perfect safety.\"[4] With reflection, refraction,\nand polarization of light, we have here no concern; therefore,\ninteresting as the subjects are, we must pass them by.\n\n[4] For further details, see the Handbook of Heliography,\nLondon, 1840; and (for preparing-paper) the Visitor, 1839,\np. 290.\n\nLight radiates from the sun with almost inconceivable velocity; that\nis, at the rate of nearly 200,000 miles in a second. Hence it is about\neight minutes in traversing the intermediate space between our globe\nand its starting point or origin. But here comes a question not easily\nanswerable. What is light? Is it matter? It is imponderable--can\nwe conceive of matter without weight? Again, whence does it derive\nits velocity? The term radiation from the sun is convenient; but,\nthen, what is radiation? Is there light, (and is there heat,) above\nthe limits of our atmosphere? We cannot tell what the nature of the\nmysterious emanation of light and heat from the sun is, nor whether\nthere are such phenomena as light and heat in empty space. Again, by\nwhat process is this enormous manufactory of solar emanation kept up?\nWe may here lose ourselves in vague conjectures: He alone knows who\nsaid, \"Let there be light: and there was light.\"\n\nThe few details which we have thrown together, bearing upon the natural\nlight of our planet, derived from the sun, will suggest to the mind\nof the Christian those apt comparisons, of the broad light of day to\nthe light of the gospel, transmitted to our souls from the Sun of\nrighteousness. Till illuminated from above, man wanders in spiritual\ndarkness; he sees neither the dangers that encompass him, nor the\nroad by which he should go; he may have the light of nature and the\nlight of science within him, but in spiritual affairs he is blind, and\nwill be chosen only by the blind as a leader. Let, however, the light\nof revelation begin but to dawn upon him, and he learns to discover\nmore and more clearly his real position, his true character, and the\nimpossibility of his finding acceptance before God upon his own\nmerits. He feels himself to be a sinful creature, and is led to rest\nupon the merits and atonement of the Son of God, who died for our sins,\nand rose again for our justification. Thus enlightened, he receives\nstrength to pursue his journey to that bright and glorious kingdom of\nwhich God himself is the Sun, and where there shall no more be night,\nwhere \"everlasting day abides,\" and all is glory and refulgence.\n\n4. _Its Temperature._--Heat and light are distinct from each other,\nthough in many cases one accompanies the other, and is produced by the\nsame cause, as, for instance, by combustion, electricity, percussion,\nthe sudden condensation of air, etc. Heat without light, however, is\ndeveloped by the physical or chemical changes of bodies, as by the\ncondensation of steam, and the admixture of water with sulphuric acid.\nIt results, moreover, from the vital and mysterious operations which\nare constantly taking place in organic beings, and especially in the\nclasses of mammalia and birds. But the great source of heat--that upon\nwhich the temperature of our atmosphere mainly depends--is produced by\nthe influence of the solar rays.\n\nThere is, indeed, heat in the body of the globe itself; to say nothing\nof volcanoes, we may state, that the deeper we penetrate into the\nearth, the higher does its temperature become--a circumstance which\nhas led many philosophers to infer, that the centre of our globe is in\na state of incandescence. It is not here that we ought to moot this\ntheory, neither shall we enter into any speculations relative to the\nintrinsic nature of heat; like light, it is a mysterious agent or\nproduct, imponderable, yet subject to certain laws--laws which belong\nto a branch of philosophy into which it is not now our province to\nenter.\n\nIt may, however, be permitted us to state a few simple facts relative\nto the atmospheric temperature of our globe, and the adaptation\nof organic beings to the different degrees of heat within the\ninter-tropics, in the temperate and in the polar latitudes. Climate\nvaries not only according to latitude, but also according to elevation,\nthe relative proportions of land and water, the nature of the surface\nof the land, the extent of forests, etc. An island, for example,\nlike England, surrounded by the sea, destitute of mountains of vast\nelevation, or of extensive morasses or forests, though lower in\natmospheric temperature during the summer months than the parallel\nportions of the continent, has a milder atmospheric temperature during\nwinter. The cold of North America during winter is greater than in the\nsame parallels of latitude in the old world. Canada, for example, lies\nparallel to the northern half of Spain and France, (between 40\u00b0 and 50\u00b0\nN. lat.) The severity of a Canadian winter is well known. At Quebec,\nthe summer is that of Paris, the winter that of St. Petersburg. At New\nYork, the summer is that of Rome, the winter that of Copenhagen. The\nsame observations apply to the eastern portions of Asia. At Pekin, the\nscorching heat of summer is greater than at Cairo, while the winters\nare as rigorous as at Upsal.\n\nTo the different climates of the globe certain plants and animals are\nespecially adapted; organic existence ranges from the poles to the\nequator. How varied, how multitudinous, how wonderful, are the forms\nand structures of organic creation, from the moss or lichen, which\ncreeps upon the surface of the rock, to the towering palm or gigantic\noak--from the microscopic animalcule or puny insect, to the ponderous\nelephant or enormous whale! But, as we have said, every distinct region\nhas, in a general sense, its own _flora_ and its own _fauna_. It is\nin tropical countries, beneath a fervid sun, that vegetation presents\nus with its utmost magnificence. There we see forests of evergreen\ntrees, palms, and arborescent ferns--there bloom flowers of gorgeous\nhue, and luscious scent--there ripen fruits of most exquisite flavour,\nattractive both to the sight and the taste.\n\nIt is there, too, that the elephant, the hippopotamus, and the\nrhinoceros, the largest of terrestrial quadrupeds, roam the plain, or\nwander in the dense forest; there are the birds conspicuous for the\ngorgeous splendour of their metallic colours, and the insects for their\nsingular forms, their lovely painting, or dazzling effulgence. Receding\nfrom the inter-tropics, we find vegetation on a less magnificent scale;\nthe trees are for the most part deciduous, various species of corn\nare cultivated, the meadows are clothed with grass, and the vine and\nthe olive flourish. Beautiful are the flowers, richly tinted are the\ninsects; some few birds are splendid, but there are no sun birds, no\nhumming birds, no birds of paradise. Receding further, we come to\nthe extreme limits of the vine, and pass from temperate to colder\nlatitudes, latitudes in which pines and firs form woods and forests,\nin which a scanty flora greets a tardy sun, in which the animals are\ncovered with fur, increasing in thickness on the approach of winter.\nBeyond this territory the arctic regions open upon us. Yet even here\nvegetable and animal life meet us; but the species are few in number:\nthe reindeer, the leming, the white hare, the musk ox, the polar bear,\nand arctic fox, are among the most remarkable. The birds are chiefly\npiscivorous, and all are migratory, passing southwards on the approach\nof winter. Coarse herbage, lichens, and mosses, vegetate during the\nfleeting summer, and lie buried beneath the snow during the winter. Yet\nare these animals and plants as well adapted for their dreary realms of\nsnow and ice, as are the animals and plants of the rich inter-tropics\nfor their luxuriant region. Take the elephant, the hippopotamus, the\nbird of paradise, or the glittering boa constrictor to Greenland, and\nthey perish; take thither the graceful palm, palmetto, or pandanus, and\nthey cease even to struggle for life. On the contrary, transport the\npolar bear and the reindeer to the torrid plains of the inter-tropics,\nand their fate is sealed. The hardy plants, indeed, which endure the\narctic regions, are, in many instances, at least identical with those\nthat flourish in more temperate latitudes, but they are not to be found\nin the low sultry plains of the inter-tropics. They constitute the\noutskirts of northern vegetation.\n\nThe inter-tropical, the temperate, and the high northern regions of\nthe globe, are characterised, then, by their own _flora_ and _fauna_;\nbut there is a distribution of organic life exclusive of latitude,\nwhich cannot but claim the attention of the naturalist. For example,\nthe marsupial animals are distributed between Australia and central\nand southern America; but the American forms, very few in number,\nare essentially distinct from those of Australia. Again, it is to\nthe warmer regions of the old world that the larger pachydermatous\nanimals are confined, such as several species of rhinoceros, the\nhippopotamus, a tapir, two species of elephant, wild equine animals,\nas the dziggetai, wild ass, quagga, zebra, etc., and various species\nof wild hog. The living indigenous pachydermata of America consist of\ntwo species of tapir, and two of peccary. On the contrary, America is\nrich in the edentata, namely, sloths, ant-eaters, armadilloes, etc. The\npangolins, however, (_manis_,) are found only in the warmer parts of\nthe old world, and the aard-vark (_orycteropus_) is a native of South\nAfrica. We might enlarge greatly upon these observations, and extend\nthem to birds and reptiles, etc., were it our design to enter upon the\nquestion; we shall only add, that in all regions animals are expressly\nsuited to the climate of the countries in which they respectively live;\nthey are constituted for the endurance either of heat or of cold, for\nself-protection against all extremes of atmospheric temperature, and\nfor the enjoyment of existence, some under the equinoctial line, others\nwithin the arctic circle.\n\nThe foregoing observations do not apply to the human race. Man was\nordained to replenish the earth; hence the pliability and energy of\nhis physical constitution, which enables him to endure the heat of the\ninter-tropics, and the cold of Lapland or Nova Zembla--to dwell in the\ndeep valley or on the lofty mountain. When we say this, we look at\nman as a species; we do not apply our remarks to individuals, or, in\nother words, we do not assert that a Samoiede would enjoy the heat of\nCeylon or Sumatra, or that the Ceylonese would endure the rigours of\narctic Siberia; we only mean, that the fact of hot and cold climates\nbeing inhabited by our race, proves that the physical condition of man\ncan accommodate itself to every extreme of natural temperature upon\nour globe. It is true, that as a general rule man modifies his food,\nhis clothing, and even the nature of his habitation, according to the\ntemperature and products of the climate. The Laplander clothes his body\nin warm furs, the Ceylonese in a scanty vesture of thin cotton. Yet the\nwild Indians of some parts of North America, and the natives of the\ndreary regions of Patagonia, are but loosely defended from the severity\nof the cold, either as it respects dress or their huts. The Scottish\nHighlander of the olden time, wrapped in his tartan, could sleep on\nthe heather of the mountain side during a bitter sleety night without\ninjury. After all, however, in the arctic regions the maintenance of\nlife is a struggle; the depressing influences of cold, cheerless skies,\nand scanty food, tend to render the powers of the mind and the bodily\nframe alike stunted and undeveloped. Nature here holds out the means of\nlife with a niggard hand, and it is from the sea principally that the\nsupply of food and other necessaries are obtained.\n\nOn the other hand, within the tropics the means of existence are\nlavishly bestowed, the stimulus of animal food is not required, while\nthe earth yields its vegetable productions in abundance; but in these\nregions, no strong motive stimulating to active exertion, the mental\npowers become enfeebled, and all those vices inseparable from habitual\nindolence are engendered. It is in the temperate regions, where nature\nis not lavish, but liberal, and yet requires the hand of labour and the\nhead of thought, that the human race is presented to us in its highest\nform, whether bodily or mentally considered. It is in such regions\nthat arts attain to perfection; that science walks hand in hand with\nreligion. A thousand necessities urge to exertion and enterprise, and\nthese are followed by a due reward.\n\nThus, then, are organic bodies, plants, the lower animals, and man,\naffected by atmospheric temperature; but man has called in heat,\nartificially produced, if we may use the word in a certain sense, to\nhis aid. Without heat, ore could not be smelted, or instruments of\nmetal made; glass and earthenware could not be manufactured; houses\ncould neither be built, nor furnished with articles of utility; the\noperations of agriculture could not be successively carried on, nor\nships built, nor steam engines or machinery be constructed, nor could\nman clothe himself or cook his food. In short, were it to please the\nAlmighty to suspend the laws of caloric, man would be rendered at\nonce helpless, and his senses useless; he must necessarily become a\ncompletely altered being, granting even that his continuance as a\nspecies upon the face of the earth were guaranteed.\n\nWith what wisdom, then, are the laws of the Almighty framed! How\nhappily do they all conjoin to fit this world for the exercise of our\nsenses and our reason! Yet, how mysterious they are! We know not even\nwhat light and caloric really are; they are incomprehensible, and\nyet we experience their influence, and daily test their laws. Who,\nthen, can wonder that the fall of man, the decrees of God, the advent\nof Christ, his Divine and human nature conjoined, his death as an\natonement of inestimable value, his intercession for all who come to\nhim with faith, and the sanctification of the Holy Spirit, are each and\nall mysteries? \"Canst thou by searching find out God?\" Yet the believer\nknows _that_ God to be his Father and his Friend; he walks by faith and\nnot by sight, \"by faith of Jesus Christ unto all and upon all them that\nbelieve,\" and are \"justified freely by his grace through the redemption\nthat is in Christ Jesus.\" When we reflect upon the mysteries of nature,\nlet us also think upon the mysteries of grace; let the consciousness of\nour own ignorance lead us to throw aside presumption, and trust to the\nwords dictated by Him, to whom all mysteries are open, and whose wisdom\nand goodness have no bounds.\n\n5. _Its Dryness or Humidity._--Evaporation from the waters of the\nglobe, from seas lakes, rivers, etc., is perpetually taking place,\nthe ratio of evaporation being determined by the temperature of the\natmosphere; that is, it increases as the temperature increases. Hence\nthe actual quantity of water in a state of invisible vapour in the\natmosphere will be the greatest when the temperature of the latter\nis the highest. Speaking according to our feelings, we then call the\nair dry, although, in fact, the quantity of water in solution in the\natmosphere may balance the demands of the temperature.[5] But this\ninvisible vapour is liable from a thousand causes to condensation,\ndependent upon one law, namely, that when a portion of air, saturated\nwith invisible vapour, is cooled below the point of saturation, a\nportion of the vapour becomes condensed, according to the degree of\ncold, so as to leave a due balance of vapour in the air, according to\nits altered temperature. Who has not seen the window-panes of a heated\nroom in cold weather bedewed with trickling moisture? The vapour of the\nroom is in abundance, although invisible; but certain strata of the air\nthus charged come in contact with the cold panes, and lose a portion of\ntheir caloric, and with their caloric a portion of their vapour, (to\nwhich, perhaps, the respiration of a large party has contributed,) and\nthis becomes condensed in the form of a visible fluid. If we breathe\nagainst a cold pane of glass, we soon render it dim by moisture. On a\nhot summer's day, we do not perceive the vapour of our breath; but on a\ncold, clear, frosty day, a visible vapour or little mist is exhaled.\n\n[5] The quantity of water in solution in the atmosphere\ncan never be greater than the quantity proper to the\ntemperature; but it may be less.\n\nFrom electric changes, from currents of air, from sudden or gradual\ndepressions of atmospheric temperature--be the cause what it may--the\ncondensation of invisible vapour in the atmosphere is perpetually\ntaking place. But the extent and degree of condensation is very\nvariable. Sometimes, or rather very commonly, the quantity of water\nseparated is small, and condensed into such minute particles that\nthey float in the air, higher or lower, forming wreaths of mist,\nor clouds of various patterns, density, and extent; sometimes they\nappear at a great altitude, like silvery waves, or snowy fleeces;\nsometimes at a lower altitude they take the shape of dense irregular\nmasses, presenting to fancy's eye the outline of monstrous animals, of\nmountains, and castellated rocks; and sometimes the whole horizon is\nbeclouded and dark; we then know that the condensation is increasing.\nWhat is the result? A fall of rain, snow, or hail, in which latter\ncase the water is not only condensed into its ordinary form, but into\npellets of ice. The water has passed through a stratum of air at the\nfreezing point. Sudden hail-storms in summer may, we think, be classed\namong phenomena dependent on electric changes and operations in certain\natmospheric strata.\n\nWe have here, then, two processes--one of evaporation, another of\ncondensation; and these, by an express and admirable provision, have\na constant tendency to limit each other's operations. Evaporation is\nincreased by heat, but it produces cold in proportion to the rapidity\nwith which it is carried on. Condensation is produced by cold, and at\nthe same time heat is liberated.\n\nHow happens it that clouds and rain are formed in the higher regions\nof the air, and not closely round about us? In consequence of certain\nlaws, the air incumbent on the earth's surface, especially in the\nhotter latitudes, is always under the point of saturation, the air\nbeing really dryer than it is at a great elevation. These laws\ndepend on the difference in the tension or elastic force of vapour\nat different temperatures; this elasticity increases rapidly from\nthe temperature of 32\u00b0 to 212\u00b0, the increase being in a geometrical\nprogression, while the increase of the temperature of the air from a\nhigh altitude to the earth is in arithmetical progression. Now the air\nof our mixed atmosphere is the ingredient which controls the whole\nmixture. The result is, that the quantity of vapour present in a mixed\natmosphere will, at any successive diminution of height above the\nsurface of the earth, become successively less and less than that which\nwould be required to saturate the air. The consequences of this result\nare most important, and are connected with our general well-being, and\nthe due exercise of some at least of our senses.\n\nThe following passage from Dr. Prout's Treatise is so pertinent,\nthat we beg leave to transcribe it: \"Over the greater portion of the\nearth, the air which, during the day at least, is warmed by contact\nwith the earth's surface, and thus becomes lighter, has a constant\ntendency to rise into the higher atmosphere. Now if this air were\nsaturated with vapour, of course, whenever by rising it became mixed\nwith colder air, its vapour would be more or less condensed, and a\ncloud would be formed. Hence, if we lived in such an atmosphere, we\nshould be always enveloped in a mist, through which the sun would\nnot be visible. But, by the benevolent arrangement we enjoy, this\nconsequence is so entirely prevented, that, unless under peculiar\ncircumstances, and always for beneficial purposes, the air at the\nearth's surface is hardly ever saturated with moisture. The air which\nhas been warmed by contact with the earth can, therefore, rise from the\nsurface without any condensation of its moisture within the limits of\nits point of saturation. Thus, at the equator, before the air reaches\nthe temperature of 61\u00b0, the presumed point of its saturation, it must\nascend to the height of 6,000 or 7,000 feet. At this height its vapour\nwill be condensed, and a cloud will be formed, which may either be\nprecipitated on the spot from which its constituent vapour had risen,\nor may be transported by the currents of the atmosphere, similarly to\nrefresh a distant country, or may again be dissolved in the air; while,\nunder all these contingencies, the whole of the lower portion of the\natmosphere is exempt from mist, and continues perfectly transparent.\nThese operations are unceasing; moreover, the very clouds, by giving\nout their latent heat, and shielding the earth's surface from the\ndirect influence of the sun, have a still further effect, and have a\nconstant tendency to modify their own formation and existence.\"\n\nWe might here enter largely into other points of high interest\nconnected with the science of meteorology, did the nature of our\nsubject allow it. We do not forget that it is upon the senses that\nwe have to write, and accordingly we can go no further here than\nto show, in a brief and succinct manner, a few of the principal\narrangements instituted by Almighty wisdom and power, which render\nour solid globe and its circumambient atmosphere the fitting abode\nof such forms of organic life as we are acquainted with, and for\nwhich, in fact, the world was created. To this world all the senses\nof animals are expressly accommodated. If there were no air, there\ncould be no organs of hearing--granting the existence of living beings\nwithout respiration. If there were no light, or the laws of light were\notherwise than what they are, our eyes would be useless. Were our lower\nstratum of atmosphere always enveloped in a dense mist, obscuring the\nrays of the sun, the sphere of our vision and its accuracy would be\ngreatly circumscribed--nay, sounds would fall more dully on our ears.\nSuppose the globe closely shrouded by an oppressive fog; and then\nimagine the condition of plants, animals, and man. Yet, did it please\nour great Creator, it is in his power to call into existence plants and\nanimals fitted for so moist and obscure an atmosphere.\n\nAgain, the atmospheric temperature, the varying degrees of heat and\ncold, according to latitude and to the characters of land--that is,\nits elevation, its depression, the nature of its surface, and the\narrangement of adjacent seas, etc., are in harmony with the development\nof life, and the due exercise of animal functions. Then, intimately\nconnected with this subject, are the laws of caloric, the suspension of\nwhich would lead to the annihilation of all organic beings at present\nconstituted. Neither can we forget the weight of the atmosphere, its\nvarying electric conditions, nor the density and attractive force of\nour planet. To these, and many other laws impressed upon matter, and\nthe results of those laws, are the physical organization of plants and\nanimals adapted, each in its own way, but yet with a mutual relative\nbearing, conducive to universal order.\n\nTo the constitution of this earth are plants, living forms destitute of\nfeeling, hearing, sight, or indeed any sense known to us, adapted--yet\naccording to their kinds they know what nutriment to refuse or reject;\nthey are subject to the influence of temperature and of light and\ndarkness; some court the broad glare of the sun, others flourish only\nin the shade. The same observations apply to certain of the lowest\nforms of animal organization, which lead a vegetable life, and appear\nnot to be aware of their own existence. Nor, indeed, is it until we\nascend high in the scale of animal being, and arrive at a point at\nwhich the senses are more or less developed, and in accordance with\nthis development, that of mind also, (for we can use no other term,)\nthat we discover a decided consciousness of existence, as manifested by\nanger, fear, and other passions; by watchfulness, sensibility to pain\nand pleasure of a mental kind; a recourse to artifice or to force as a\nmeans of gaining certain ends; and other proofs of a something--call\nit mind, or any other name--to which the senses appeal.\n\nFor, let us remember, it is only in a certain sense that the eye sees,\nor the ear hears; in the former instance, nothing more than an image\nof objects is inversely reflected on the retina, and yet the mind\nrecognises these objects in their proper position; and what is more,\nnot double, though the same object is figured on the retina of each\neye, or, in the case of insects, on the retina of scores of eyes. In\nhearing, the minute auditory nerves merely receive an impulse from the\nvibrations or wavelets of the elastic atmosphere, and this constitutes\nwhat we call noise, tones, music, voice. But these tones or noises are\nin the mind only; they are not appreciated by the exercise of any other\nsense.\n\nHaving thus briefly endeavoured to show the harmony of the general\norder of nature, as far as our globe and its animal and vegetable forms\nare concerned, we shall proceed to the consideration of another portion\nof our subject, and commence with it a fresh chapter.\n\n\n\n\nCHAPTER II.\n\n     MAN'S KNOWLEDGE OF THE QUALITIES OF MATTER OBTAINED THROUGH THE\n     MEDIUM OF THE SENSES.\n\n\nIf we reflect upon man, beginning with the savage, and ending with the\nphilosopher, we shall find, that although the mental difference, or\nrather the extent of acquired knowledge possessed by each respectively,\nis very great, that the little the one possesses, and all that the\nother may boast of, are based upon certain simple principles, seized\nupon by the mind through the medium of the senses, and made more or\nless the subjects of consideration and research.\n\nIf the philosopher can display a mass of knowledge of which the savage\nis ignorant, the savage can show to the philosopher that his mind in\nsome things is more ignorant than his own. Both have used their senses;\nboth have examined and reflected; both have accumulated a store of\ninformation, which they turn to account: but the savage cares only\nfor that which enables him to enjoy animal existence. He, therefore,\ninvestigates the habits of the animals around him, and the nature of\nthe plants; he tames some of the former, he cultivates some of the\nlatter; he stores up provisions, he invents rude weapons; he builds\nkraals, or huts; he fashions boats, kajaks, or proas; he employs\nfire; and though he cannot discuss the laws of caloric, he knows\nmany of them practically. In fact, his senses are to him the inlets\nof ideas, without any abstruse cogitation. He cannot but acquire\nknowledge through his senses, but he labours to acquire no more than\nis subservient to his present interest. To the philosopher, the senses\nare also the inlets of ideas; but then he is thereby led to abstruse\ncogitation, to experiments, and reiterations upon these, forming\ntheories to be rejected or adopted, as laborious investigation may\ndetermine.\n\nAnd wherefore?--Not contented with the vacuity of mere animal\nenjoyments, he antedates his spiritual existence, and while yet on\nearth soars to other worlds, or dives into the profound mysteries\nof nature. Between the rude savage and the philosopher there are\ninnumerable gradations; yet the rude savage, if cultivated, might\nbecome the philosopher--and why?--Because, though mental powers, like\nbodily powers, differ, the mental anatomy, like the corporeal, is on\nthe same plan; and, figuratively speaking, the muscles of the former\nmay become by exercise as developed as the muscles of the latter. To\nwhat fields, then, of knowledge are the senses avenues--and avenues,\nbecause they are adapted to the condition of the globe we inhabit,\nand because the impressions which they receive are seized upon by\nthe mind, being there alone made palpable; and because the mind, by a\nreflex action, thence derives ideas, and combines and analyzes them.\n\nThe higher animals possess the same senses as man; and, it may be\nasked, Why do they not gain a similar knowledge to that which man\nacquires? We have already said, that the higher animals possess\nsomething which cannot but be termed mind, since they have passions\nand affections, memory, etc., which are qualities of mind, and not of\nmatter. But, then, their mind is not only inferior in degree to that\nof man, but different in its anatomical construction. Certain animals,\nmoreover, are inferior to others, and among animals of the same species\nthere are different degrees of mental as well as of bodily force.\nHere, however, we can only generalize. Let it suffice, then, that we\nadduce for the purpose of illustration an animal with which we are all\nfamiliar--a domesticated animal, capable of a high degree of education,\nand which man has trained to the most various and opposite purposes--we\nallude to that attached servant of our race, the dog. Let it stand as a\ntype of the higher quadrupeds.\n\nThat the dog remembers, and even to a certain extent reasons, cannot,\nwe think, be contradicted. A shepherd's dog not only obeys its master's\ndirections, but of its own accord will keep the sheep together,\nprevent them from wandering out of the right track, search for them\nwhen buried in the snow, watch over them at night, and defend them\nagainst the incursions of the wolf. The sportsman's dog, when he\nsees his master take down his fowling-piece, examine the locks, and\nequip himself for the field, is quite aware of the result of these\nproceedings, and manifests unequivocal symptoms of pleasure. Dogs,\nmoreover, may be taught to beg, to fetch and carry, to feign themselves\ndead, and continue motionless until the word of command be given, and\nto take their part in a scenic representation. There are, indeed,\nnumerous authentic instances on record of dogs having acted with\nastonishing sagacity, and which prove not only memory, but a train\nof reasoning carried out with singular precision. In such instances,\nwe cannot say that the animals are instinct-directed, because the\nactions performed are out of the common course of events, and are only\noccasional; every dog, under the same circumstances, would not act in\nanything like the same manner.\n\nThere are, however, bounds beyond which the most intelligent dog\ncannot pass; and why?--the anatomy of his mind is different from that\nof man. His senses, that of touch excepted, are as acute as those of\nman, some far more so, but his reasoning powers are confined within a\nsmall circle. For example, education does not really elevate the dog\nover the wild packs of his own species--it rather rivets the chain\nwhich binds him to man as his lord; it enfeebles his instinct, and\nrenders him at once more dependent and more useful; it places him in\nmany different, and in a certain sense, unnatural spheres of action; it\nrenders him a shepherd, a guard, a hunter, but it adds not positively\nto his information; he has no ideas of the beautiful or the sublime--of\ntruth, of virtue, and vice--of humanity, pity, charity; he reflects\nnot that death is his doom, even though he sees from time to time his\ncompanions expiring around him. It is, in fact, first, because the most\nelevated ideas or reasonings of the dog are merely simple, and those\nwithin a narrow compass; and, secondly, because the dog is utterly\nincapable of forming any abstract idea that education cannot elevate it\nabove itself. It has not man's mental anatomy. The rudest savage can\ndevise the bow, and the spear, and various other implements; he can\nfashion them because he has hands, but his hands are only the servants\nof his mind; had not his mind been what it is, his bodily organization\nwould have been otherwise, but still in just harmony. In the savage lie\nthe dormant germs of lofty intellect, and in his line, at some future\ngeneration, may a Milton, a Shakspere, a Newton, arise; sage poets,\nstatesmen, and philanthropists, men of whom England boasts--England,\nwhose children are the descendants of a semi-barbaric horde, which\nspread ruin in its westward progress.\n\nBut what the dog was in the earliest ages, what it was in the times\nof classic history, that it continues to be; on the contrary, man can\nemerge from a savage to a civilized state; acquire new wants and supply\nthem; improve upon first principles, and take step after step in the\npursuit of knowledge; add improvement to improvement; begin by building\na frail coracle, and then launch his steam-ship on the water--begin by\nerecting a low kraal, and then erect the palace of C\u00e6sar, or the temple\nof Athens.\n\nReflex operations of the mind are denied to brutes--even to the dog,\nan animal which the Almighty evidently created for the special service\nof man: hence, though the avenues to their minds are the same, reason\nhas but a feeble grasp upon the sensations which there enter; and\nthat mysterious power, quality, or impulse, which we term instinct,\nrises predominant, and leads to operations which in man could only be\nthe result of reflection and experience. Yet, as we have said, the\nactions of the dog, and we may add of the elephant, the horse, and\nother animals, are not all instinctive, neither do all the actions\nof man proceed from a train of reasoning, for some of his, even,\nare instinctive: the love of offspring on the part of the mother is\nentirely instinctive in its source.\n\nIt is, then, easy to see how it is that even the highest brute,\nwith a mind limited as we have described, and with instincts which\nguide in the place of mind, can never improve or add to any store of\nknowledge, can never conceive one abstract idea--such as eternity,\ninfinity, matter, space, etc.--and can never investigate the laws\nof creation--can, in fact, be only what it is. The utmost extent of\nsomething like knowledge which the most intelligent and sagacious\ndog acquires, dies with it, and its successor has to learn all for\nitself. As for language, in the true meaning of the word, of what use\nwould it be to brutes? Among the highest, as far as the necessity of\ncommunication extends, cries or modulations of tone and certain actions\nsuffice to convey a distinct meaning; among the lowest, there is no\nnecessity even for utterance, and there is no sense of hearing, nor\neven of vision. Language supposes a mind constructed like that of man,\nand as he emerges from a rude to a cultivated state, in like proportion\nwill his language increase in copiousness and perspicuity, if not in\nforce.\n\nLet us here, without bewildering our reader in a maze of metaphysics,\njust glance at a few of the characteristics or faculties of mind,\nbriefly anatomizing them, in order that we may clearly exhibit the\nmental distinction between man and the higher orders of beasts, by way\nof showing what the mind in each case derives from the inlets of the\nsenses.\n\n1. _A Knowledge of Self-existence, or Personality._--This knowledge\nappears to us to be rather instinctive than the result of reflection,\nas some believe; we know intuitively that we exist, because we feel,\nbecause we see and hear, because we move, because we hope and fear;\nnor will all the arguments which Berkeley or his disciples can adduce,\nconvince any person that he exists only in idea.\n\nThat animals of the higher grades, at least, have this knowledge is\nvery evident; gregarious habits, mutual recognition, the watch and\nward system, characteristic of so many species both among mammalia and\nbirds--a thousand circumstances which our readers may call to mind,\nprove it. We need not insist upon the subject. It is a feeling rather\nthan a portion of knowledge; it is intuitive, and experienced alike\nby the ploughman at his work, by the horses who labour in the furrow,\nand the busy rooks which follow in their track. Where there is fear,\nor pleasure, or pain, or desire, there must self-consciousness be--a\nfeeling of self-existence. We have no reason to believe that plants\npossess this feeling.\n\n2. _Memory._--Memory is a mental exercise, or faculty, of the greatest\nimportance to man; it is in constant requisition; without it our\nintellectual improvement would be confined within very narrow limits.\nOur acquirement of language, and of the rules of sciences and arts,\ndepend upon this faculty, and it is strengthened by habitual exercise.\nBetween memory and recollection, there is a slight shade of difference.\nA man may say, \"I remember the events of the year 1848\"--\"I recollect\nsuch an event, now that you mention it.\" Events may be recollected\nafter being forgotten, and often are so in illness--nay, forgotten\nlanguages have sometimes been fluently spoken. It often happens--why\nso, we cannot say--that circumstances or events, long passed from\nthe mind, present themselves suddenly to it with extreme vividness,\nand are thenceforth remembered; but oftener does it happen, that\nthe sight of some object, or that a sound, a note, a tune, a word,\nrecalls to the mind forgotten events, bygone circumstances, hopes\npassed away, pleasures long fled, feelings long quiescent. This\nspecies of recollection has been called by some writers the \"power\nof association.\" It certainly depends upon an association of ideas,\nwhich, on the key-note being struck, pass involuntarily through the\nmind; a sight or sound will often call to mind, with singular rapidity,\na vision of other years, or of scenes far distant, towards which the\nheart intently yearns. Witness the effects of the air of the Ranz de\nVache upon the Swiss soldiers in Napoleon's army. Recollection is often\nthe result of attention. We remember a certain event, but forget the\nyear in which it occurred; we direct our thoughts to the subject, we\ncompare circumstance with circumstance, date with date, until at last--\n\n    \"It breaks upon the mind, and all is clear.\"\n\nThat brutes possess memory is indisputable; indeed, we might fill\npages with instances of the power of memory in animals, some rather\nstartling; but as common every-day observation enforces the fact upon\nalmost every one, we need not insist upon it. However, by way of\nadding interest to a disquisition some may deem dry, we will introduce\nthe following anecdote, related by Mr. Corse, in his Observations on\nthe Natural History of the Elephant:[6] \"In June, 1787, F\u00e2ttra Mungul,\na male elephant, taken the year before, was travelling in company with\nother elephants towards Chittagong, laden with a tent and some baggage\nfor our accommodation on the journey. Having come upon a tiger's track,\nwhich elephants discover readily by the smell, he took fright and ran\noff to the woods, in spite of the efforts of his driver. On entering\nthe wood, the driver saved himself by springing from the elephant,\nand clinging to the branch of a tree under which he was passing. When\nthe elephant had got rid of his driver, he soon contrived to shake\noff his load. As soon as he ran away, a trained female was dispatched\nafter him, but could not get up in time to prevent his escape. She,\nhowever, brought back his driver, and the load he had thrown off, and\nwe proceeded without any hope of ever seeing him again. Eighteen months\nafter this, when a herd of elephants had been taken, and had remained\nseveral days in the inclosure, till they were enticed into the outlet,\nthere tied and led out in the usual manner, one of the drivers, viewing\na male elephant very attentively, declared he resembled the one which\nhad run away. This excited the curiosity of every one to go and look at\nhim; but when any person came near, the animal struck at him with his\ntrunk, and in every respect appeared as wild and outrageous as any of\nthe other elephants. At length, an old hunter coming up, and examining\nhim narrowly, declared he was the very elephant that had made his\nescape about eighteen months before. Confident of this, he boldly rode\nup to him on a tame elephant, ordering him to lie down, and pulling him\nby the ear at the same time. The animal seemed quite taken by surprise,\nand instantly obeyed the word of command, with as much quickness as the\nropes with which he was tied permitted; uttering at the same time a\npeculiar shrill squeak through his trunk, as he had formerly been known\nto do, by which he was immediately recognised by every person who had\never been acquainted with this peculiarity.\" The same observer informs\nus, that another elephant, a female, taken in 1765, was turned loose in\n1767, and retaken in 1782. She then recollected the customs and words\nof command learned during her former bondage; she laid herself down at\nthe command of her driver, he fed her from his seat, gave her his stick\nto hold, which she took with her trunk, put it into her mouth, and\nreturned it as she was directed, and as she had been accustomed to do.\n\n[6] Phil. Trans., 1799.\n\n3. _Attention._--Attention is an abstraction of the mind from a\nmultifarious variety of trifles, or circumstances, and an energetic\ndirection of it to one subject, or object. In attention many, if not\nall, the senses may be engaged. For example, a botanist gathers a\nflower; its beauty, the form and substance of its petals, their colour,\nits aroma, the honey-dew of its nectary, the peculiarity of its calyx,\nand other qualities, appeal to the mind through the senses of sight,\nsmell, taste, and feeling. He has to describe this flower--he fixes his\nmind upon it, and puts forth a graphic delineation in apt and concise\nlanguage. The ploughman is at work, and the sower of grain follows\nhim--both give their whole mind to their duty. The critic (oh, word of\nfear!) gives his attention to the matter under his revision; and so\ndoes the cook, when preparing a _recherch\u00e9_ dish on the composition\nof which he prides himself. And does not the tiger, crouching in\nambush, give attention to his object, stimulated in the meantime by\nhope? Who has not observed multitudes of cases, affording examples of\nattention in brutes? In fact, attention is a faculty displayed by all\nbrutes, especially by those which lead a life of rapine, for upon its\nexercise depends their daily support. But man alone can direct his\nattention to things intellectual, abstruse, or religious. The reason\nis evident--the brute is incapable of abstract ideas, but quite awake\nto its own present necessities. The high realms of thought belong to\nman alone, of all terrestrial beings; but in how far higher a degree to\nthose spiritual existences, those angels of light, which surround the\nthrone of God, and who, contemplating with amazement the finished work\nof salvation, exclaim, \"Worthy is the Lamb that was slain to receive\npower, and riches, and wisdom, and strength, and honour, and glory,\nand blessing!\" nay, till we mingle with these transcendent beings, the\npowers of our mind will be pressed down beneath a load of clay; then\nall that was dark shall be made clear, and with angels we shall join\nin saying, \"Amen: blessing and glory and wisdom and thanksgiving and\nhonour and power and might be unto our God for ever and ever!\"\n\nBut we are told that there are angels \"which kept not their first\nestate,\" and which are reserved \"unto judgment of the great day;\"\nnamely, Satan and his apostate subordinates. Fallen though they be,\ntheir brightness \"has not lost all its original splendour;\" but they\nexercise their high powers in tempting and seducing to his eternal ruin\nman, whom Satan by his wiles has already crushed, and robbed of his\noriginal innocence. Let us strive against the tempter, the deceiver,\nwho lays luxury, licentiousness, gold, fame, power, before his willing\nslaves, trying them on every point, and inducing too many to fall\nirrecoverably. But God's thoughts are higher than our thoughts, or\nthan the thoughts of man's crafty adversary; and in wisdom he devised\nthat mighty scheme, through which rescue and pardon are freely granted\nto all who accept the invitation of the Redeemer, \"Come unto me, all\nye that labour and are heavy laden, and I will give you rest;\" \"All,\"\nhe says, \"that the Father giveth me shall come to me; and him that\ncometh to me I will in no wise cast out,\" John vi. 37. Jesus is the\nConqueror, and death is swallowed up in victory. Flee, then, from the\ncity of destruction; and though the slough of despond or the valley of\nhumiliation be before, press forward, awakened sinner, to the heavenly\nJerusalem! on that let your thoughts be placed.\n\n4. _Comparison._--The direct comparison of one object with another,\nwith a view towards the acquisition of information, is exercised\nby man alone of all animals; but that superficial and involuntary\ncomparison which leads to the simple _distinction_ of things, as of\nland from water, or trees from houses, is common both to animals and\nman. _Choice_ supposes the exercise of comparison, in a low degree, and\nthis a bird displays in the selection of a spot for its nest, and the\nbeaver in that of a site for its dam and village. In both these cases,\nhowever, _instinct_ impels to the labour, and supplies the place of\nexperience.\n\n5. _Knowledge of Cause and Effect._--A knowledge of the connexion\nbetween cause and effect is the result of experience alone. We thus\naccumulate a number of facts, and by reasoning upon those facts, can\ninfer with certainty what would be the result under such or such\ncontingencies. That brutes gain information to a certain extent by\nexperience is very plain. We have seen a monkey break nuts by hammering\nthem upon a stone--we have seen the orang try to pick the lock of its\ndoor with a bit of stick--we know instances of horses disengaging\nthemselves from their headstall, unbolting the stable door, and making\noff to the pasture; a cat in our possession was accustomed to leap up\nand open the latch of the kitchen door, whenever she wished to enjoy a\nstroll. We might multiply examples, but so many will suggest themselves\nto the reader's mind, that we may spare ourselves the task.\n\nWith a knowledge of the connexion between cause and effect is\nassociated that of _power_. Give me where to stand, said Archimedes,\nand I could move the world. Man's natural powers are very limited, but\nhis comprehensive mind enables him to overcome the most formidable\nobstacles; to bore through the mountain, to uproot it from its base,\nand scatter its fragments over the plain; to over-arch rivers and arms\nof the sea with iron pathways; to travel as rapidly as most birds\nfly; to upheave ponderous masses of stone, and to compress light\nand flocculent materials until they become solid and heavy. But man\naccomplishes all this and far more, not by his own bodily powers, but\nby machinery of various kinds, and of various degrees of simplicity or\ncomplexity; nay, he cannot even cultivate the soil, except by the aid\nof implements, that is, simple machines.\n\nBrutes entirely depend upon their own bodily powers, and gain a\nknowledge of the extent of those powers by experience. An old hunter\nwill never attempt a leap which he knows he cannot accomplish--a\nyoung, fiery horse will make a dash at it, and perhaps fail; if he\nsucceed, his dependence upon himself will be confirmed; on the other\nhand, should he not succeed, it is more than probable that he will lose\nall self-confidence, and therefore be henceforward useless for the\nchase.\n\nThe elephant skilfully uses its tusks as levers, in the uprooting of\ntrees; and when the megatherium and mylodon wrestled with the noblest\nproductions of their primeval forests in South America, they applied in\nthe best manner their forces and the means at their command. What is\nthis but a knowledge (limited, we allow) of the relationship between\ncause and effect? The camel, when overladen, utters loud cries,\nand refuses to rise at the command of the driver; this was also a\npeculiarity of the llama, when that animal was exclusively the carrier\nof the Andes.\n\nWith respect to a knowledge of power, as regards ourselves personally,\nor as displayed by brutes, we cannot help thinking that much depends\non an _instinctive perception_, added to, no doubt, by experience.\nAll animals, from man downwards, apply their force according to their\nconformation; the horse kicks--the lion strikes with his terrible\npaw--the hyena seizes with his jaw--man uses his arms; but man also\nbrings art to aid him in his bodily exertions. Hence the strongest\nman falls under the skill of the trained wrestler; but the contest of\nbrutes is that of force. Hence it is that man invents weapons which\nrender the weak and the strong on a level, and which give to skill\nthe predominance over force. This, too, implies a knowledge of the\nrelationship between cause and effect, but a knowledge which brutes,\nif we except the chimpanzee, do not display. The chimpanzee, it is\nasserted, uses a club as a weapon, but we do not advance this as a fact\npositively established; indeed, we doubt it; we have never seen this\nanimal use a stick, as we should use it in striking.\n\n6. _Time._--Man alone can invent artificial methods of measuring time;\nin an uncivilized condition he avails himself of the sun and moon,\nof the changes of day and night, of the tides, of the seasons, using\nthem as natural chronometers. The higher brutes evidently possess\nsome knowledge of time, as evidenced by the migration of birds, the\nrelief of each other, as in the case of pigeons, at stated intervals on\nthe nest, and, perhaps we may add, the storing up of food for future\nconsumption. On this latter point, however, we will not insist, for\nmost probably it is the result of an entirely instinctive impulse;\nwe have known a caged squirrel make a hoard. The dog, says M. Ebz\u00e9ar\nBlaze,[7] \"reasons, calculates, knows how to count the days of the\nweek, and even those of the year. Thus, for example, a dog belonging\nto M. Roger went every Saturday, at two o'clock precisely, from\nLocoyarne to Hennebon, (a distance of three kilom\u00e8tres;) it set off\nin a straight line to the butcher's, because that was their day for\nkilling, and he was certain of having a good regale upon tripe. He was\ncapable, then, of counting the days, since he never left home except on\nthe Saturday. At the house of the same M. Roger, family prayer was kept\nup every evening, and the dog listened to the service tranquilly, but,\nas may be supposed, impatiently, for as soon as the last _paternoster_\nwas commenced, he rose up and placed himself near the door, in order to\nmake his exit immediately on its being opened.\"\n\n[7] Histoire du Chien.\n\nWe do not pretend to say that all animals calculate time, or that any\nhave the power of calculation which man has; and as for any abstract\nidea respecting time or eternity, it is out of the question. Hence they\nneither look back upon time, nor forward into the future. Their measure\nof knowledge is wisely allotted to them; it is in due accordance\nwith their animal wants, and final destiny; but man, the heir of\nimmortality, destined to exist throughout eternity, is so mentally\ngifted as to be able to think and reflect upon the past, the present,\nand the future. Were he not immortal, he would never, perhaps, have\nbeen endowed by his Maker with the idea of a future life. However this\nmay be, the Holy Scriptures assure him of a life to come, and for which\nhe must prepare himself only by one way. The hopes of the idolater are\nfalse. Oh, then, how desirable it is that a knowledge of the true\nway of salvation should be spread throughout the world; that error\nand superstition should be banished; and that the light of the gospel\nshould cast its heavenly radiance over the benighted regions of the\nearth!\n\n7. _Locality._--A knowledge or perception of locality, that is, of one\nplace as distinct from another, is regarded by some as a result of the\nagency of an exclusive mental power; but for ourselves, we see in it\nonly the exercise of attention, leading to distinction, and involving\nthe aid of memory. To attempt to prove that man is endowed with this\ncapability is useless; so is the dog, so is the cat, so are all our\ndomestic animals. Attention, distinction, and memory, are exercised\nby the carrier-pigeon; when let free, at a long distance from home,\nit returns, and rests on its old abode. But what are we to say in the\ncase of other animals, as the dog, the cat, and the horse, travelling\nback from a great distance to their home, without having gained the\nexperience of the pigeon by soaring aloft, and surveying a wide extent\nof land below? It is well known that year after year the swallow and\nthe martin, and other migratory birds, return to the same spot, in\norder to rear their brood. Swallows and martins have been marked,\nso that there could be no possibility of mistake. These birds take\ntheir departure in autumn, journeying southwards; they then traverse\nEurope, and cross the Mediterranean; they winter in the warmer regions\nof Africa, and on the return of spring they commence their northern\nflight. What directs the course of a particular pair of swallows from\ncentral Africa, over land and sea, to a particular cottage or barn\nin Middlesex, Surrey, or Berkshire? Again, with respect to the bee,\nwhich wanders miles away from its hive, visiting fields and gardens in\nquest of honey--how is it guided in its outward and homeward flight?\nHas it landmarks?--does it know each wall, each hedge-row, each\ntree, each garden and field over which it passes? If so, how do the\nbees find their way to and from the floating apiaries on the rivers,\nthrough various parts of the European continent, and also in Egypt,\nthe resting-place being continually changed according to the judgment\nof their owners? In Egypt it is the practice to transport the apiaries\nto distant places, in order to take advantage of the succession of\nflowers. \"In Lower Egypt, for example, about the end of October, the\nbee-keepers embark on the Nile, and migrate with them to Upper Egypt,\ncalculating to arrive there when the inundation is rapidly subsiding,\nand the flowers are beginning to bloom. Having stayed a short time in\none place, till they suppose that the bees have collected all the honey\nand wax of the district, they remove two or three leagues lower down,\nand so on, as the plants come into bloom. Thus gradually returning\nhomewards, they collect the honey of the adjacent country; and about\nthe beginning of February, having travelled the whole length of Egypt,\narrive at the spots whence they had set out, and at their habitations.\nNiebuhr saw, between Cairo and Damietta, a collection of four thousand\nhives, in their transit from Upper Egypt to the Delta.\"[8] How do\nthe bees, their locality being thus changed from time to time, find\ntheir way, not only to the boat of hives, but to their own peculiar\nhives respectively? There are points in the economy of animals which\nwe cannot fathom, and it is better to confess our ignorance than to\nattempt a puerile theory. To speak truly, we cannot answer the question.\n\n[8] Nat. Cyclop.\n\n8. There are certain qualities of mind, certain principles which,\nwhatever doubt may be held respecting our previous observations, at\nonce distinguish man, and elevate him far above the highest brute. In\nfact, they take him out of the pale of the brute creation, and isolate\nhim amidst the living creatures by which he is surrounded. He is the\nonly animal being who can form any idea of God and his attributes, of\neternity, of virtue and vice, of justice and mercy; in his breast alone\nare implanted conscience, faith and hope, repentance and spiritual\npeace. Herein have we an argument, to prove that man is not made to\nbegin and end his career on this world, beautiful as it is, and fitted\nto meet all his animal powers, senses, and enjoyments. Why, indeed,\nshould these principles be implanted in man--principles immediately\nbearing upon a future state of existence, if that future state were\nnot ordained? Where in creation can a similar anomaly be demonstrated?\nEvery brute is gifted with vital functions and organization fitted to\nits destined mode of life, and with a kind and degree of mind (where\nthis is needed) in exact accordance thereunto. Beyond this all is\nblank; indeed, the most wonderful works which brutes perform, and\nwhich in man would argue great thought and experience, are in them the\nresult of instinct alone. The beautiful corals and zoophytes, which we\nso much admire, are instinct-built tenements. Instinct teaches the bee\nhow to arrange her waxen cells, and load them with honey as a provision\nfor the winter, and the bird how to build her nest. On the contrary,\nthe operations of what may be called mind, in contradistinction to\ninstinct, are displayed only by the higher brutes, and, more over, are\nlimited within narrow bounds.\n\nWe have heard persons assert, that a dog manifests the workings of\nconscience, because it often betrays itself by its timid, irresolute\nmanner after pilfering, as if conscious that it had done wrong. The\nfact is, that the dog is conscious of no moral guilt; it has been\npreviously punished for a like offence, and fears a repetition of the\npunishment; this is the solution of the whole affair.\n\nWe have so far shown the great superiority of the mind of man above\nthat of even the highest brutes, and not this only, but its essential\ndifferences, thereby rendering its possessor, indeed, the paragon of\nanimals. Let us now endeavour to explain what information is gained by\nhim from the exercise of the senses.\n\nIn speaking of God, and of celestial beings, we always use, and\ncannot but use, language drawn from the properties, qualities, and\nappearances of things around us, or from the passions of our own minds,\nor from the configuration and actions of our own bodies. We cannot, in\nfact, conceive of God except figuratively--hence to the limit of our\nintellect is the language of Scripture adapted. Though written under\ninspiration, it was written by men, and for men; and, therefore, the\npersonification of the Almighty is unavoidable. It is said, \"Thy way\nis in the sea, and thy path in the great waters, and thy footsteps\nare not known;\"[9] we talk of the \"work of his hands,\" of \"the arm of\nGod,\" etc., and we know that we are speaking figuratively, and it is\nbecause we know this, that we turn with disgust from the pictures,\nhowever elaborate, which, painted by Roman Catholics, represent the God\nof heaven and earth under the similitude of an aged man, with a long\nbeard, and white hair, looking down from the clouds. We know that \"God\nis a Spirit,\" but we have no conception of what a spirit is; we know\nnothing of spirit--nay, we know nothing of matter essentially; it is\nonly of some of its properties that our senses afford us information,\nand it may have many properties, for the discernment of which no senses\nhave been bestowed upon us. Well, then, may it be written, \"Canst\nthou by searching find out God? canst thou find out the Almighty unto\nperfection?\"[10] We cannot, however, doubt, that the Almighty has given\nto us a mind and senses quite adequate, not only to our animal wants,\nbut to our spiritual pilgrimage through this transitory scene, until we\narrive at those realms of bliss, where ignorance shall be exchanged for\nknowledge, and every difficulty cleared away.\n\n[9] Psa. lxxvii. 19.\n\n[10] Job xi. 7.\n\nConsiderations like these add interest to the inquiry--What variety and\nextent of information do we, as intellectual, immortal beings, gain\nthrough our senses? A little thought will convince us that, without\nthe reflective agency of our minds on the impressions received by\nthe senses, and the power of conceiving abstract ideas, the simple\nimpressions of colour, solidity, weight, sound, flavour, or odour,\nwould be but meagre sources of knowledge. As it is, they are the broad\ninlets of knowledge. Let us take them in succession, commencing with a\nnew chapter.\n\n\n\n\nCHAPTER III.\n\n     THE SENSES, AS THE INLETS TO KNOWLEDGE--SIGHT AND HEARING.\n\n\n1. _Sight._--The information acquired by the mind through the sense of\nsight is more varied than that communicated through any other sense,\nsingly taken; but it is less accurate. The sense of sight requires\neducation and assistance, and both are given through the sense of\ntouch. We have already said, that light radiates from bodies, and\nforms a picture on the retina, (a reversed picture,) conveying to the\nmind certain qualities of matter, and, first--colour. By variations in\nthe shades of colour, and by contrasts of colour, our eye, aided by\nexperience from the sense of touch, determines the form of objects; and\nthe boundaries of these forms we term outlines. All that we perceive\nis the limits of differently coloured spaces. Where, however, colours\nblend gradually into each other, the limits of each space, and,\nconsequently, its outline, are indefinite; we do not see matter, but\na quality of matter. There are circumstances under which the eye is\ndeceived respecting colour, two or more different colours producing\na similar effect on the retina, and being undistinguishable from each\nother. Moreover, when the retina is fatigued by a prolonged impression\nfrom one colour, its sensibility to colour is diminished, and we cease\nto judge accurately; in these instances, the retina receives those only\nwhich are termed _accidental_, namely, which do not enter into the\ncolour steadily gazed at previously. For example, \"if we look steadily\nat a white spot, and afterwards turn the eye towards white bodies, a\ndark spot will be perceived by the eye. If we look at a red spot on\na white ground, and then direct the eye to another part of the white\nground, a green spot approaching to blue will be perceived. In the\nfirst case, the retina was fatigued by the white colour, and could not\nbe excited by any other colour having the rays which constituted it in\nits composition. The _accidental_ colour, therefore, was black. In like\nmanner, after looking at the red spot, the retina was insensible to the\nimpressions of a compound colour, having red rays in its composition.\nHence, the accidental colour consisted of the other rays of the\nprismatic spectrum, forming a colour destitute of red.\"\n\nThe eye is subject to deception, or illusion. Sometimes we mistake the\nshadow for the substance. The rays of light, passing through media\nof different densities, are refracted at different angles; hence the\ndirection or nearness of different bodies becomes apparently altered,\nand experience alone corrects the error. On putting a pole or stick\nobliquely into clear water, the submerged portion seems to be bent\nat the surface of the water, and to rise higher in the water than it\nactually is. The bottom of a deep, clear river, or pond, seems to be\nnearer to the surface than it is in reality; in other instances, the\nwater deceives by an apparent shallowness, the truth of which the\ninexperienced bather should always test before venturing in. If a gold\nor silver coin be put at the bottom of a basin, and the basin be then\nfilled with water, and the eye be obliquely directed, so as not to\nsee the coin, hidden by the rim of the basin, it will become apparent\nwhen the basin is filled. In spearing fish, allowance is made by the\nexperienced for the difference of refraction of the rays of light in a\nrare and more dense medium. It is probable that birds which prey upon\nfish, by darting at them while at a certain distance under the water,\nas, for example, the fish-hawk, or osprey, and the gannet, are taught\nby _instinct_ to correct an apparent error of sense, or rather, an\nillusion, which man corrects by practice and experience.\n\nThe eye is deluded by the mirage. The mirage (a French word, adopted\ninto our language) is \"the name given to a phenomenon of unusual\nattraction, for which we have no specific appellative, unless it be the\nsea-term _looming_. As a general definition, we may say, the mirage is\nan optical illusion, occasioned by the refraction of light through\ncontiguous masses of air of different density, such refraction not\nunfrequently producing the same sensible effect as direct reflection.\n\n\"The illusions of the mirage differ according to circumstances, but\nthey may be all arranged under one or other of the three following\nclasses: _vertical reflection_, _horizontal_ or _lateral reflection_,\nand _suspension_.\"\n\nIn hot, flat regions, as certain portions of Arabia, Egypt, Persia,\nthe western deserts of India, etc., the _vertical mirage_ is extremely\ncommon; it presents the illusive appearance of a wide, clear lake, or\nsheet of water, in which trees, buildings, and other objects, seem to\nbe reflected, and in a reversed position. On approaching this deceptive\nlake, it keeps receding as we advance, the reflected images vanish,\nto be succeeded by others, as they come in rotation into sight. And\nthus the wayworn and thirsty traveller across the desert is first\ncheated into hope, and at length mocked into despair. During the\nFrench campaign in Egypt, under Napoleon, the soldiers, who suffered\nextremely from the torments of thirst, were cruelly tantalized by the\ndeceptive mirage. M. Monge, one of the savans who accompanied the army,\nthus comments upon this phenomenon: \"The soil of Lower Egypt,\" he\nobserves, \"is a vast plain, perfectly horizontal, its uniformity being\ninterrupted by a few eminences, on which, in order to secure them from\nthe inundations of the Nile, the villages are built. In the morning\nand the evening the aspect of the country presents nothing remarkable,\nall objects appearing in their natural positions, and at their proper\ndistances; but after the soil has become heated by the rays of the\nsun, the prospect seems bounded by a general inundation. The villages\nat a little distance appear as islands in the midst of an expansive\nlake, and the image of each village is seen invertedly reflected, as\nif the water were real. As we advance, the mimic water retires, still\nreflecting image after image;\" so that in this illusion the classic\nfable of Tantalus is represented; might not the fable have had its\norigin in the phenomenon of the mirage?\n\nIt is not, however, exclusively on sandy plains or in very hot\nclimates, that this mirage occurs. It has been observed by Biot over\nthe sandy beach of Dunkirk, and is not unfrequent along the coast of\nCalvados. A strange and beautiful effect of the mirage was seen by\ncaptain Maundy, at the Shallout Pass in India, and is thus described:\n\"A deep precipitous valley, at the bottom of which I had seen one or\ntwo miserable villages in the morning, bore in the evening a complete\nresemblance to a beautiful lake. The vapour which played the part of\nwater, ascended nearly half-way up the sides of the vale, and on its\nbright surface the trees and rocks were distinctly reflected.\"\n\nHow like the vanities and pleasures of earth is the mirage! Bright,\nsparkling, illusive--an appearance without a substance--a mockery\nwhich deceives, attracts, and vanishes away! He who pursues the\npleasures of this world, and all its tinsel gratifications, resembles\nthe fevered traveller in the burning desert, who pursues the mirage,\nwhich recedes as he presses eagerly towards it, till at length,\ndiscovering its nothingness, he perishes.\n\nWe may next consider the mirage produced by _horizontal_ or _lateral\nreflection_.\n\n\"In the horizontal or lateral reflections, the mirage represents the\nreflected image sideways. Thus, on the 17th of September, 1818, M.\nJurine and Soret observed a lateral mirage on the lake of Geneva. A\nbark, about four thousand toises distant, was seen approaching Geneva\nby the left bank of the lake, and at the same moment there was seen\nabove the water an image of the sails, which, in place of following the\ndirection of the bark, receded from it, and seemed to approach Geneva\nby the right bank of the lake, the image sailing from east to west,\nwhile the bark was sailing from north to south. This lateral mirage\nis known to the inhabitants of Meroa, who call it _Si-kot\u00e9_, (castle\nof the cold season;) by those who live on the plains watered by the\nChumbul and the Jumna, it is termed _Dissaser_, (prognostic.)\n\n\"In particular situations, both the _vertical_ and _lateral_ mirage\nmay be observed together. Thus the late Mr. Blackadder has described\nsome phenomena, both of vertical and lateral mirage, as seen at king\nGeorge's Bastion, Leith, which are very instructive.\n\n\"The phenomenon called _suspension_, which is the third kind of\nmirage, and to which the term _looming_ is most strictly applied, is\nthe picturing of an object immediately over it in the air, frequently\nwithout reversion of the image. Sometimes the objects are merely raised\nabove the height at which, under ordinary circumstances, they would\nappear. Thus sir R. K. Porter mentions a phenomenon of suspension, or\n_looming_, in the plains near Bagdad. 'A little before morning,' says\nhe, 'I observed an elevated stream of water, which, from its situation,\nmust be the Tigris. Its surface was brilliantly illuminated by the\nmoon, but the longer I kept my eye fixed on this noble river of many\ninterests, the more my surprise became excited at the extraordinary\nheight of its waters above the level of the desert, till at length\nI began to suspect that some optical illusion from refraction was\nassisting the apparent elevation of the stream; but I had not conceived\nthe extent of the deception, for as the dawn advanced the phantom\nriver totally sunk from my sight.' The phenomenon of _looming_ is most\ngenerally observed at sea, or near the shore. At Reggio, in Calabria,\nthe _Fata Morgana_ (Fairy Morgana) is visible, which for many centuries\nastonished the vulgar and perplexed philosophers.\n\n\"It frequently happens that the phenomenon of the _vertical_ mirage is\ncombined with that of _suspension_, so as to show in the air both a\ndirect and an inverted image of the subject, the latter being undermost.\n\n\"Now all these phenomena, and their various modifications, depend on\nthe different density of the lower strata of the air; and as this\ndifference of density may be occasioned both by heat and moisture,\nand as heat may be reverberated from the mountain's side as well as\nfrom the horizontal surface of the plains, from the sea as from the\nland--and, further, as contiguous columns of air, as well as horizontal\nstrata, may be of different densities, it is easy to conceive why\nthe mirage may be seen in very different situations, as also why it\npresents such varied appearances. It will also be evident that any\ncause which re-establishes the equilibrium of density in the different\nportions of the air, must cause the illusions of the mirage to\nvanish.\"[11]\n\n[11] Penny Cyclop\u00e6dia.\n\nIt cannot be doubted that those appearances, which sailors call _Cape\nFly-away_, the _Enchanted Island_, and the _Flying Dutchman_, etc., are\nthe effects of the mirage. They are the objects of superstition, and\nthus has an illusive appearance caused many a heart to beat with fear,\nwhich never so beat in the tempest or the sea-fight.\n\nThe eye assists us greatly, indeed almost exclusively, in determining\nthe _motions_ of bodies; yet in this we require experience, and after\nall we are frequently deceived. When a body moves in a straight line\nfrom us, we cannot tell whether it moves or not, and then only come\nto the conclusion that it recedes in consequence of its becoming more\nobscure, and from a change in its relative position to other objects\nwhich we know to be stationary. When we travel in a railway carriage,\nthe banks, the hedge-rows, and the fields, seem as if gliding with\nextreme velocity away from us. It is only by a course of reasoning that\nwe know such is not the fact; it is true that the course of reasoning\nis very short and simple, yet still that reasoning is requisite;\nindeed, it has been acknowledged only in modern times that the sun\nis stationary, and that the world moves. Bodies moving with extreme\nvelocity produce a continuous impression on the eye; thus, for example,\nif a stick burning at one end be rapidly whirled, the burning end\nproduces the appearance of a fiery circle. The spokes of a coach-wheel,\nrolling round very rapidly, present the appearance of an indistinct\nexpansion. On the contrary, bodies moving with extreme slowness appear\nto casual observation as stationary; thus the act of growing, in\nordinary plants and animals, is not appreciated, though the result is\ndemonstrated in due time.\n\nThe eye, moreover, may be deceived by artificial representations, as\nby painting (take the Diorama as an example) or by models. We have\nseen flowers so truthfully modelled in wax that, by the eye alone, no\ndistinction between them and natural flowers could have been detected.\n\nThe same observations apply to _magnitude_ and _distance_. Objects of\ngigantic magnitude, as, for instance, the pyramids of Egypt, at first\nappear less than they are in reality; and it is only by admeasurement,\nexamination, and comparison, that the mind becomes impressed with\nthe idea of their immensity. A building, the details of which are\nin just harmony, always appears to be smaller than it is, because\nno discordance betrays the vast preponderance of certain parts over\nthe littleness of others. Habit, or, in other words, education, is\nessentially requisite to aid the eye in its appreciation of magnitude.\n\nWe may say the same with respect to _distance_. An infant does not\ndistinguish between near and distant objects; its eyes have yet to\nbecome educated, and so have those of adults placed in circumstances to\nwhich they are unaccustomed. For example, the walls of a city, reared\nin a vast level plain, and descried at a distance, appear to be far\nnearer than the traveller will find them to be; again, when standing on\nthe beach, we look at a ship in the distance, we are apt to think it\ncloser to the shore than we should prove it to be were we to traverse\nthe distance in a boat. A sailor would judge of the distance accurately.\n\nHow much the accuracy and utility of the eye depend upon practice or\neducation may be illustrated by the case of a boy, who, as described by\nCheselden, was born quite blind, but was suddenly restored to sight, at\nthe age of twelve, by the skilful removal of the cataract. At first,\nhe was impressed with the idea that all the objects which he saw around\nhim touched his eyes, in the same manner as in the act of touch they\ncame in contact with the skin. He could neither estimate distance, nor\ndistinguish one object from another, until he had applied the test of\ntouch as a corrective and assistant.\n\nIt may here be asked, how the fact is to be explained that, though\nimages are pictured on the retina inverted, we do not see them as such,\nbut in their true position? When we say that the eye sees, we use\npopular, but not strictly correct language; the eyes are the organs\nor instruments of vision--that is, for transmitting certain qualities\nof matter to the mind; it is not the image on the retina which the\nmind contemplates, for we are utterly unconscious that such an image\nexists--it is the object itself. \"To expect that the impression from an\ninverted image on the retina should produce the perception of a similar\nposition in the object viewed, is to commit the error of mistaking\nthese images for the real objects of perception, whereas they are only\nthe means which suggest the true perceptions. It is not the eye which\nsees; it is the mind.\" \"The analogy which the optical part of the eye\nbears to a camera obscura has perhaps contributed to the fallacy in\nquestion; for in using that instrument we really contemplate the image\nwhich is received on the paper, and reflected from it to our eyes; but\nin our own vision nothing of this kind takes place.\"\n\nWe scarcely know whether we can place among optical illusions those\nstrange apparitions of departed persons, of friends at a distance,\nor of singular and grotesque faces or figures, of which we have many\nauthentic narratives. These we take to be strong impressions on the\nmind alone, (for no image can there be on the retina,) the result of\nsome morbid condition of the brain and nervous system. Such was the\nevil genius which Brutus saw in his tent before the battle of Philippi,\nand such the air-drawn dagger of Macbeth--such also were the phantoms\nseen by Nicolai, the philosophic bookseller of Berlin, who has given\nan admirable account of his mental visions, referring them to their\ntrue source, at the very time that the illusions visited him. In some\nstates of body, we see grotesque and ludicrous objects, while our eyes\nare shut, and, as we can testify, often not before we have shut our\neyes, and thereby closed the door of access through those organs to the\nmind. What horrible phantasms terrify the unhappy sleeper labouring\nunder night-mare! What strange things does the delirious sufferer\nmentally behold, and through what strange scenes, real to him, does he\npass! We see, we converse, we laugh, we mourn, we feel pleasure and\nanguish, even in our dreams. These, then, are not optical but mental\nillusions--no figure is made upon the retina appealing to the mind,\nbut the mind itself sees things which are not, and is delighted or\nterrified by its own involuntary creations.[12]\n\n[12] See \"An Essay towards a Theory of Apparitions,\" by\nJohn Ferriar, M.D., 1813; and \"Sketches of the Philosophy\nof Apparitions; or, An Attempt to trace such Illusions to\ntheir Physical Causes,\" by Samuel Hibbert, M.D., 1824.\n\nIn former times, craft, under the name of religion, availed herself of\nthese mental illusions, and extorted gifts of lands and gold from the\nterrified, perhaps most guilty sufferer, in order that his peace with\nthe church (so miscalled) might be made, and masses said for the repose\nof his soul. He was taught to buy his entrance into heaven--not with\nthe Pearl of great price--not by presenting before the Judge of all\nmankind the merits and the atonement of the Messiah, but by founding\na monastery, or by adding to its treasures and domains. His faith was\nplaced, not on the promises of God in Christ, but on the promises of a\nmere mortal at best--yes, a mortal, who knew that while he promised he\nwas weak as other men; In concluding our observations upon the sense of\nsight, we may refer to a few striking passages in Scripture, of great\nforce, and well calculated to excite reflection. \"He that formed the\neye, shall he not see?\"[13] No secrets are hidden from God; no, not the\nsecrets of the heart, for these are written on a tablet which he, and\nhe alone, can read. May our prayer be, \"Let the meditation of my heart\nbe acceptable in thy sight, O Lord, my strength, and my Redeemer!\"[14]\n\"Enter not into judgment with thy servant: for in thy sight shall\nno man living be justified.\"[15] In the sight of God, we speak\nfiguratively, all men are sinners, and as sinners condemned; but God\nwill not enter into judgment with those who, by faith in the atonement,\nlooking to the Saviour, as the Israelites looked to the brazen serpent\nin the wilderness, turn away from their wickedness, and become examples\n\"of the believers, in word, in conversation, in faith, in purity.\"\n\n[13] Psa. xciv. 9.\n\n[14] Psa. xix. 14.\n\n[15] Psa. cxliii. 2.\n\n2. _Hearing._--What we call sound, noise, or tone, is a mental\nappreciation of the effects of the tremulous or vibratory motions\nof the particles of an elastic fluid, such as air or water, on the\nauditory or acoustic nerves of the internal ear. Sonorous vibrations\nare produced by the concussion of hard bodies, by the bolt of\nlightning, by the vibrations of stringed instruments of music, by the\nforcible current of air thrown into the tubes of wind instruments,\nand by the air driven from the lungs through the organs of voice in\nreptiles, birds, and mammalia. There are, indeed, few movements, few\ncollisions, few atmospheric disturbances, which do not excite those\ntremulous wavelets of atmosphere, those oscillations, which produce\nin us the sensation of sound. In fact, during the day, the sense of\nhearing is as perpetually employed as is that of sight; yet, strange to\nsay, from the impressions made through the medium of both these senses,\nwe can so far abstract the mind, and throw it upon its own internal\nreflections and operations, as to see without discrimination, and to\nhear without attention or notice.\n\nAs sound is the result of the tremulous fluctuations of air, it will\nnot surprise our reader to know, that no sound is conveyed from\nthe percussion of bodies in a vacuum. The experiment of suspending\na bell in the exhausted receiver of the air-pump, and causing the\nclapper to strike it as when rung, has been very often repeated; no\nsound is communicated to the listener, although the vibrations of\nthe bell are clearly perceived; should a little air be now admitted,\na faint tinkling is heard, which becomes stronger in proportion to\nthe admission of air, until it is natural; on the contrary, if the\nreceiver be filled with greatly condensed air, the tinkling of the bell\nis louder than it is when in an atmosphere of the ordinary degree of\ndensity.\n\nSound, or, rather, the wavelets of the atmosphere producing this\nsensation, radiate from the sound-causing object in all directions;\nthese wavelets, however, extend only to a certain distance, according\nto the violence of the central agitation; they become gradually feebler\nand feebler, and at last die away. Thunder, the firing of cannon,\nand the clang of trumpets, are not heard beyond a certain distance,\nand even at that distance, whatever it may be, the ear only faintly\ndistinguishes the report, for the vibratory action and reaction on each\nother of the atmospheric particles, become feebler and feebler in\nproportion to the a\u00ebrial distance of the listener.\n\nIf we stand on an eminence commanding a view of a number of cannon,\nsay a mile distant, which the soldiery are from time to time firing,\na decided difference of time will be perceived between the flash and\nthe report; the same observation applies to lightning, a considerable\ninterval often occurring between the flash and the thunder. Hence,\nlight is said to travel faster than sound. Sound travels at the ratio\nof about twelve miles and a half in a minute, but its velocity is\ngreater in a denser than in a rarer medium, as is also the distance to\nwhich it is propagated. These points are illustrated by a comparison\nof water with atmospheric air. All aquatic animals are not constituted\nfor hearing; myriads, indeed, have neither sight nor hearing. By the\ncuttle-fishes (_cephalopoda_) both these senses are enjoyed as well\nas by fishes, aquatic reptiles, and we need not say by such aquatic\nmammalia as whales, grampuses, porpoises, etc. To them the water is\nthe medium of sound, and granting that their auditory nerves have the\nsame sensibility as those of man, they will hear sounds not only more\nquickly, more distinctly, but at greater distances. This is accounted\nfor by \"the greater elasticity of the constituent particles of water,\nwithin the minute distance required for their action in propagating\nsound. Stones struck together under water are heard at great distances\nby a person under water. Franklin found, by experiment, that sound,\nafter travelling above a mile through the water, loses but little of\nits intensity. According to Chladini, the velocity of water is about\nfour thousand nine hundred feet in a second, or between four and five\ntimes as great as it is in air.\"\n\nDifferent bodies conduct sound to the ear with more or less\ndistinctness, according to their susceptibility for vibrating, and\nalso with more or less rapidity. Ice, for example, conveys sound\nmore speedily than water, and far more rapidly than air; thus, if a\ncannon on the edge of a frozen lake be fired, a person on the opposite\nside will find the flash to be followed by two reports, the first\nconducted to him by the ice, the second by the air. If a long steel\nrod be applied to the orifice of the ear, the gentlest jar given to\nits further extremity, and which, but for the intervention of the\nmetal, would not have been audible, produces a strong and distinct\nimpression. Cotton wool, sheeps' wool, and soft stuffs, generally are\nbad conductors of sound. The frozen earth conducts sound from great\ndistances; the approach of a horseman in clear, frosty weather, will be\nheard at a far greater distance than when the ground is moist, or not\nhardened; in the former case, indeed, a double sound may sometimes be\nheard, one produced by the vibration of the ice-bound earth, the other,\nif distance allow, by that of the air.\n\nThe distance to which sound can be conveyed through the\nspeaking-trumpet is very surprising. The invention of the modern\nspeaking-trumpet is generally accorded to sir Samuel Moreland, (1670,)\nand some of the large brass trumpets, made under his direction, carried\nthe human voice from a mile and a half to between two and three miles\ndistance. The efficiency of this instrument has been attributed to\nthe repeated reflection of the sound, or waves of air, (like rays of\nlight,) from side to side along the course of the tube, their ultimate\nefflux from the mouth of the instrument being in such a way, as either\nto cause the rays of sound to be collected into a focus at a distance,\nor to be projected forward in parallel lines, instead of allowing\nthem to diverge in all directions, and on these principles various\nmodifications in the form of the speaking-trumpet have been suggested.\n\nThe views, however, of professor Leslie do not coincide with this\ntheory. \"The performance of the speaking-trumpet,\" he says, \"does\ncertainly not depend upon any supposed repercussion of sound; repeated\nechoes might divide, but could not augment the quantity of impulse.\"\nHis idea is, that \"the tube, by its length and narrowness, detains\nthe efflux of air, and has the same effect as if it diminished the\nvolubility of that fluid, or increased its density.\" \"The organs\nof articulation,\" he adds, \"strike with concentrated force; and\nthe pulses thus so vigorously excited are, from the reflected form\nof the aperture, finally enabled to escape and spread themselves\nalong the atmosphere.\" The experiments of Hassenfratz, a French\nphilosopher, are cited in support of this theory. He tried the power\nof a speaking-trumpet, by measuring the distance at which the ticking\nof a watch could be heard through it, and found the effect the same,\nwhether the metal tube were used simply, or wrapped round in such a way\nas to prevent vibration. It was also heard at the same distance when\nthe inner surface was lined with linen, or woollen cloth, to diminish\nreflection; and the range of a cylindrical trumpet was the same as that\nof a conical one.\n\nIn the ear-trumpet, used by persons partially deaf, and in the\nstethoscope, it appears to us that we have concentrations of sound into\na focus, by repeated reflexions of the a\u00ebrial wavelets from side to\nside of the tube; and we may ask, does not the murmuring sound which we\nhear, when we apply a conch shell to our ear, arise from the same kind\nof percussion?\n\nIn echoes we have an instance of the reflection of atmospheric\nundulations, and this reflection, as in many natural situations, may\nbe multiplied till the last faint repetitions die away; and when\na succession of echoes is very rapid, a loud exclamation of the\nmonosyllable, Hah! may be thrown back upon the ear like a boisterous\nlaugh. The echoes of old halls and galleries, of vaults and dungeons,\nof caverns, rocks, and grottoes, have served as subject-matter for\nthe writers of imaginative poetry and romance. It is not only to old\nromantic halls and galleries that echoes are confined; they are not\nuncommon in modern public buildings, so that the speaker hears his\nwords repeated. \"The distribution of sound in public edifices, so that\nthe echoes (or reflections of a\u00ebrial waves from the walls, etc.) may\nbe most advantageously brought to strengthen the original sound, is\na subject deserving of much attention.\" For some observations on the\nerrors of architects on this point we may refer to sir J. Herschel's\nTreatise on Sound.\n\nWhen our auditory nerves receive a succession of uniform impulses at\nequal intervals of time, the intervals being at the same time very\nsmall, the impressions become so interblended with each other as to\nproduce an apparently continuous sound, even and equal, except as to\nvariation in loudness. This sound we call a musical note, produced\nby the string of the violin, or piano; if the intervals between the\nvibrations be, comparatively speaking, long, the note is grave; but if\nwithin the same given time the vibrations be very numerous, the note\nis in proportion acute. Some notes harmonize with each, and thereby\nplease the mind through the ear; others are discords, and offend. Grave\nor acute notes depend upon the length and the tension of the strings\nof an instrument, or the length of a wind instrument. In the piano,\nthe low notes are produced by long, thick strings, the high notes by\nslender, short wires, in which the vibrations are excessively rapid.\nIn the violin, which has strings of equal length, the thin strings for\nproducing the high tones are screwed to a far greater degree of tension\nthan those of the lower tones; and each string, as its length (that is,\nvibratory length) is shortened by the pressure of the finger at due\nintervals, produces high and higher tones in proportion.\n\nWe have here said enough (for we aim not at a treatise on acoustics)\nto show what sound really is, and what are the principal laws by which\nit is governed. We have also shown, that it is our mind alone that\ntakes cognizance of the impulses given by vibratory wavelets of the\natmosphere to the auditory nerves; consequently, that as the mind sees,\nso the mind alone hears, for vibration cannot in and of itself be that\nsensation which we call sound.\n\nWhat is the knowledge gained through the ear by the appreciation of\nsound, or in common language, by hearing? Let us answer:--We commonly\njudge of the distance and position of objects producing sound by the\nsense of hearing, but in these points our accuracy greatly depends\nupon our attention and our experience. Yet are we liable to deception;\nwe are thoroughly deceived by a skilful ventriloquist, who can so\nmodulate his voice as to make it seem distant or near, or to proceed\nfrom one quarter of the room or house, or from another. The voice of\nthe corn-crake (_Crax pratensis_) is, from some cause or other, very\nperplexing; sometimes it will appear as if the bird were only a few\nyards distant from us, and the next instant in some far part of the\nfield. Perhaps instinct leads it to alter the pitch of its monotonous\ncry, in order to deceive the intruder. Again, echoes deceive the ear;\nnot only may we mistake echo for the actual voice of the speaker, but\nit may appear as if close or distant, faint or loud, and thus in every\npoint lead to erroneous conclusions.\n\nThat the ordinary animals around hear will not be denied, nor can we\nblind ourselves as to the fact, that they acquire a limited share of\ninformation, bearing upon their corporeal necessities, through this\nsense. Animals have a natural language, expressive of pain or pleasure,\nof surprise, of fear, of anger; and this language consists of cries or\ntones, variously modulated, each species having its own range of vocal\nintonations. Every species understands the simple instinctive language\nof its own species. Some birds, for example, as the wild geese, have\nsentinels around the flock while feeding, and rise _en masse_ at the\nwarning cry of their guards. Who has not marked the distress and\nagitation of the ewe, when she hears the plaintive tremulous bleat of\nher lamb, forcibly separated from her? The warning note of the cock,\nhis cluck of invitation, his scream of surprise or fear, his cackle\nof agitation, his crow of defiance, are well understood by his train.\nQuadrupeds, birds, and even some insects call to each other, and are\nanswered again--\n\n    \"Steed answers steed with loud and boastful neighing.\"\n\nThe bird invites his mate by a sweet strain, and is answered by her\nlow chirp. The call of the young in their nests is responded to by the\nparents; the parents call to each other, as if to assure themselves of\neach other's safety, or to find out where they mutually are, and what\nthey are doing.\n\nImitation is an instinct; we see it powerful in its dominion over\nchildren; it is in exercise before reason assumes a definite sway; it\nprompts to the acquisition of the mother-tongue, till, by repetition,\nthe true pronunciation is acquired, and the names of all common\narticles known: then reason steps in. But imitation is not confined\nto the human race; monkeys imitate, and the grotesqueness of their\nimitations renders them ludicrous; they do not imitate voice, but\naction. Some birds, however, imitate the human voice, and are easily\ntaught to utter words or sentences, (the parrot, the mino-bird, the\nmagpie, are examples,) nay, even to sing musical airs with great\naccuracy. But, by all this acquisition through the organ of hearing,\nthey gain no information, nor add to the limited number of their ideas.\nThe parrot may be, indeed, made by practice to associate the sound of a\nword, say bread, with the article thus denominated, and to call for it\nby name when wanted; but reason steps not in to give further assistance\nin the building up of idea upon idea, without which there can be no\ndefinite language--no real speech. Though the dog and the horse cannot\nutter the sound, they know what bread is quite as well as the parrot,\nand, indeed, the ear of the dog is the inlet to an instinctive mind of\nno mean order, for the Almighty created the dog to be man's assistant\nand humble friend.\n\nThe question has been often mooted, as to whether song-birds acquire\ntheir respective warble or song by the ear alone, that is, by listening\nand imitating, as a child would do, or whether it is intuitive;\nthe answer is not very easy. There is an impulse in song-birds to\nexpress their feelings of pleasure or enjoyment, by giving utterance\nto modulated sounds, so pleasing to the human ear, that their song\nleads too frequently to their friendly imprisonment. Young birds,\nbrought up by their parents, and with a vocal pipe best fitted for the\nenunciation of the strain of their parents, (or rather male parent,)\nrapidly acquire that strain, and soon begin to record, or try it over\nin an under tone, and bearing it in memory, break out into full song\nwhen leafy spring returns. Nevertheless, birds, taken early from the\nnest, and put under the tuition of other birds, acquire to a certain\nextent the song of the latter, often, indeed, apparently perfect; yet,\nperhaps, could our ears catch it, we should find that the bird had much\nof the parent accent in its acquired language.\n\nThough birds receive ideas of a simple character, and express simple\nfeelings, understood by each other, through the medium of various\nsounds, yet nothing from age to age is thereby added to their\nknowledge; they remain what they have been from the commencement of\ntheir creation. Their ears are far less the inlets to knowledge than\ntheir eyes, and this observation applies generally to the lower animals.\n\nNow let us turn to man. Setting aside meaningless sounds and noises,\n(some of which, however, through the association of ideas, are very\ngrateful, as those of the multifarious denizens of a farm-yard,) man\nderives both pleasure and knowledge from a definite succession of\nsounds, which appeal to his mind, as sound cannot appeal to the mind\nof the lower orders. How laughable is the fabled contest of the lutist\nand the nightingale, and of the death of the latter disappointed of\nthe victory--the lutist might have enjoyed the warbling of the bird,\nbut the bird could not have entered as a rival into the strains of the\nlutist. Nevertheless, from personal observation, and from the most\ncredible authorities, we fearlessly assert, that many animals are\nallured by sweet sounds; we have seen rats peeping out of their holes,\nlistening to airs played on a flute; and sir Walter Scott says,\n\n    \"Rude Heiskar's seals through surges dark,\n    Will long pursue the minstrel's bark.\"\n\nA little lizard (the _anolis_) in the West Indies, and snakes in North\nAfrica and India, are attracted by the notes of a rude pipe; to deny\nthis is futile; it has been proved in modern days, and the fact is\nnoticed in Scripture. Some animals, when certain notes are struck,\nor certain keys tried over, are decidedly agitated, and perhaps feel\nas we do when some horrid sound \"sets our teeth on edge,\"--that is,\nirritates by a mysterious sympathy the whole nervous system. In the\nsame way, perhaps, are animals pleased with certain sounds; that is, a\nsympathetic tranquillity or pleasing excitement of the nervous system\nis produced, and they yield, instinctively, to \"the voice of the\ncharmer.\"\n\nWith regard to ourselves, music (we need not enter into a learned\nexplanation of what it is) operates far less upon the reasoning than\nthe instinctive faculties of man. Tones, modulations, swellings, and\ncadences, though no words be sung, excite all the emotions of which\nour animal nature is capable. But when words are used--when music is\nmarried to immortal verse, and an appeal through language is also made\nto the mind, then, indeed, the effect is tremendous. A song shouted\nforth in the streets may overturn an empire. Who knows not what was\nthe effect of the Jacobite songs in Scotland, when Charlie came \"o'er\nthe water?\" Who knows not the effects resulting from _Caira_ and\nthe Marseillaise Hymn? Whose bosom has not beat high when our own\nnational hymn, when Rule Britannia, and other patriotic airs, have\nbeen energetically and effectively delivered? In fine, who is there\nthat is not affected by music? very few; it is and has been a natural\nexpression of human feeling appealing to human feeling, since the time\nof Jubal even unto the present day; and Miriam's song of triumph, and\nthe songs (how mournful!) of the daughters of Judah on the willowy\nbanks of Babel's rivers, were equally expressive of natural emotions.\n\nMusic, then, without words, appeals rather to our animal feelings than\nto our reason or mind; music, with suitable words, appeals both to our\nanimal feelings and our mind; and music, with merely recollected words,\ndoes the same by concatenation of ideas; and this also is often the\nresult of tones, passages, and cadences, to which we have never heard\nwords applied; hence, we talk of a lively air, a merry air, a martial\nair, a melancholy air; and hence a great poet wrote--\n\n    \"That strain again! it had a dying fall.\n    Oh! it came o'er my ear like the sweet south,\n    That breathes upon a bank of violets,\n    Stealing and giving odour.\"\n\nSome airs, again, are solemn, and tend to fill the mind with awe, or a\nfeeling of devotion; deep strains of melody were those which resounded\nthrough the great temple, when the holy psalms of the shepherd-king\nwere chanted, and deeply was every heart moved to the worship and\nadoration of the living God. Oh, such should ever be our sacred music!\nPerhaps we are wrong, but we confess that the sweetest air composed for\nan ordinary song, (however pure, elegant, or patriotic that song may\nbe,) when introduced into the house of God grates upon our feelings. We\ndivide literature into profane and sacred (meaning nothing offensive\nby the term profane)--let, then, music be as strictly divided, so\nthat the association of ideas which a popular air will, in spite of\nourselves, engender, shall not creep in to intertwine with the sacred\nexercise of praise and thanksgiving to our Creator and Redeemer, which\nalone should engage the full force of our mind.\n\nThe power of music in elevating the mind, in cheering it, or, on the\ncontrary, in depressing it, has been felt from the earliest ages. When\nSaul was troubled in spirit, \"David took an harp, and played with his\nhand: so Saul was refreshed, and was well, and the evil spirit departed\nfrom him.\"[16]\n\n[16] 1 Sam. xvi. 23.\n\nWe have said, that animals appeal to each other through the organs of\nhearing by cries or sounds, nor is man destitute of natural cries,\nwhich are universally understood--the shout of exultation, the scream\nof terror, the shriek of agony, the moaning of mental or bodily\nsuffering, and the sobs of sorrow, speak to every heart. But, besides\nthese instinctive tones, man acquires a definite language, more or\nless extensive, more or less capable of expressing abstract or complex\nideas, and ever in these points bearing progress with the advancement\nof the arts, with the civilization and with the religion of the people.\nThere are some savage tribes who cannot count a hundred, but we can\ncount to hundreds of millions, till the mind becomes overwhelmed with\nthe vastness of the numerical progression, which, let each unit stand\nfor a million of years, would, after all, infringe not on eternity.\nLanguage is the appeal of definite sounds, through the organs of\nhearing, to the mind; these sounds are arbitrary; they do not in any\nway represent things, or the qualities, or the state of things; for,\nindeed, language is based altogether on a system of association--it has\nto be acquired; that is, the mind has to be taught to associate certain\nsounds with certain mental perceptions; but these sounds do not mean\nthe same thing in every language or dialect. On this point we need not\ninsist, neither need we give examples, which must suggest themselves to\nevery reader, if he reflects that there are other tongues beside that\nwhich he speaks.\n\nThough language consists in a system of sounds uttered by the mouth,\nappealing through the sense of hearing to the mind, yet man has\ncontrived to effect the same purpose through the eye, and hence\nis enabled to convey to others at a distance his thoughts, his\nobservations, his wishes, and views--to transmit to posterity the\nresults of his labours and researches, or the outpourings of his\ngenius. His plan is to employ certain marks or characters, drawn or\nimpressed on paper, bark, wood, metal, or other materials, which\ncharacters shall be understood. These characters, which we call an\nalphabet, represent sounds; they are made up into words, and as our eye\nruns along them the varying sounds of the words are suggested, and with\nthem the meaning; this is termed reading, and if we utter the words,\nreading aloud.\n\nBut there are other characters, not alphabetical, which have been, and\nstill are, in use, and which are symbols of ideas, and not of sounds.\n\"While the letters of our alphabet are mere symbols of sounds, the\nChinese characters or written words are symbols of ideas, and alike\nintelligible to the people of Cochin-China, Japan, Loo-choo, and Corea,\nwith those of China itself. As the best practical illustration of a\nwritten character, common to several nations who cannot understand each\nother's speech, Mr. Davis adduces the Arabic numerals, common to all\nEurope. An Englishman, who could not understand what an Italian meant\nif he said _venti-due_, could comprehend him immediately if he wrote\ndown _twenty-two_. This advantage, which belongs to our numerals only,\npertains to the whole language of the Chinese. The uniformity, however,\nin the written character, does not prevent the existence of great\ndiversities in the oral languages of the neighbouring countries and\nChina, and even of the separate provinces of the latter country. These\ndiversities are precisely analogous to the different pronunciation\ngiven to the same numerical characters in the various countries of\nEurope.\n\n\"To adduce the foregoing example--the number 22, which the Italian\ncalls _venti-due_, a Frenchman pronounces _vingt-deux_, and an\nEnglishman _twenty-two_, though all three write them just alike. It\nis in this manner that the universality of the Chinese language\nextends only to the written character, and that the natives of the two\nextremities of the empire, who read the same books, and understand\neach other perfectly on paper, are all but mutually unintelligible in\nspeech. The roots, or original characters of the Chinese, are only\ntwo hundred and fourteen in number, and might, indeed, be reduced to\na much smaller amount by a little dissection and analysis. These are\ncombined with each other to form other words, or express other ideas,\nvery much in the same way that the individual Arabic numerals are\ncombined to express the infinite varieties of numbers. By a species\nof analogy, they may be called the alphabet of the language, with the\ndifference that exists between an alphabet of ideas, and an alphabet of\nsounds.\"[17]\n\nWhen the Chinese wish to write a European proper name, they have\nrecourse to a contrivance which in some respects approaches the\nphonetic hieroglyphics of ancient Egypt. The Chinese characters when\nthus employed do not become alphabetic, but represent the entire\nsyllable or sound which they express in ordinary use. Thus, if we\nsuppose A, B, C, to stand respectively in the place of three Chinese\ncharacters, intended to give the name _Maria_, the mode would be thus--\n\n  +-+\n  |A|   _Ma_   Jasper\n  |B|   _Li_   Profit\n  |C|   _Ya_   Second in rank.[17]\n  +-+\n\n[17] See Klaproth's Examen, etc., p. 25.\n\nIn ancient Egypt, two modes of writing were practised, namely, the\n_common_ and the _hieroglyphic_. There were several kinds of _common_\ncharacters, and also, as it would appear, of _hieroglyphics_. Clemens\nof Alexandria distinguishes from both the _hieratic_, which was used by\nthe sacred registrars. The ancient Mexicans employed pictorial writing;\nand of this nature we may consider the Bayeux tapestry, representing\nthe chief incidents of the invasion of England by William I. Savages\noften give information to their friends, or convey their wishes, by\ncutting rude figures on the bark of trees, the meaning of which is at\nonce understood by every individual of the tribe.\n\nOn these points we have sufficiently enlarged. Our main purpose is\nnow to show how great an inlet to knowledge the ear is. To the eye\nspeak the writings of antiquity, the accumulated wisdom of successive\ngenerations, the experience of sages, and those holy records which\ncontain the oracles of God, the sacred truths, and the revelation\nof the purposes of the Almighty towards a fallen race. It is by\nlanguage, as it appeals to the eye, that we commune with the mighty\ndead--that we receive into our minds the sublime ideas of a Milton,\nthe learning of a Bacon, or the philosophy of a Newton. But it is\nto the ear that the conversation of ordinary life is directed; the\ndirections, the requests, the commands that we continually issue forth\nor receive--words of congratulation, consolation, encouragement, or\ninformation--the eloquence of the senate or the bar--the strenuous\nadmonitions or exhortations of the preacher. What a wonderful thing\nthe mind of man is, that a few atmospheric vibrations on the auditory\nnerves, or a few pictures on the retina, should produce sorrow or joy,\nhope or fear--should communicate instruction or pleasure--should excite\nsympathy or love, contempt or aversion! And, again, how wonderfully\nis the organic frame constructed, and adapted to the conditions of\nour planet, that light and air should communicate through two of our\nexternal senses with the mind, affording it food for cogitation, stores\nof knowledge, and intellectual gratification! Does this arise in any\ndegree from the superiority of the organs of sight and hearing in man?\nCertainly not. The vulture, soaring in the upper sky, far excels man in\nthe power of vision. Yes, and so does every bird that skims the air, or\nhovers in quest of prey over the surface of the great deep. The dog,\nthe horse, the antelope, and numerous other lower animals, have quicker\nears than man; but then the mind! it is there that the difference lies;\nwith a weaker sight than is usual, with a more imperfect hearing than\nis ordinary, sages and philosophers, and historians and poets, have\nleft to posterity the brightest productions of mental power. Homer and\nMilton were blind.\n\nThrough the sense of hearing man communicates orally with man, and man\nutters his prayers and praises orally to God, as if God heard with\nears like those of organic beings. It is natural that we should thus\naddress ourselves to the Almighty, because our conceptions of him are\nnecessarily limited by the measure of our minds, expansive as regards\nthe lower creation, but narrow--oh, how narrow!--compared with the\nwisdom of the uncreate Eternal. \"He that planted the ear, shall he\nnot hear!\"[18] It matters not whether we murmur forth with our lips,\nor silently think them in our mind--God hears them. He hears the\nlanguage of our heart, the aspirations and vows of our inmost soul:\nand he knows, too, (and he alone can know,) whether we be sincere\nor the contrary. The tongue of the hypocrite may deceive men, but\nnot God; nay, we may deceive ourselves by our own verbiage, but God\ndistinguishes the prayer inspired by the Spirit of truth, from the\nempty declaration of excitement.\n\n[18] Psa. xciv. 9.\n\nThus, then, is the ear an inlet of a vast amount of knowledge to\nthe mind; it conveys what the eye cannot convey, and it assists the\neye, while in turn by the eye it is assisted; and, indeed, that one\nsense shall support another, and be again supported, or corrected,\nis ordained by our Creator, who in wisdom has fashioned our mortal\nframework, the tenement of an undying soul.\n\n3. _Taste._--The sense of taste conveys to the mind an impression from\nobjects, very dissimilar to that which is gained through the medium of\nthe eye or of the ear; nay, dissimilar to that conveyed by the sense of\ntouch.\n\nThe sense of taste resides in the mouth; that is, it pervades the\ntongue, the palate, and the pharynx, on which are distributed fine\nramifications of the fifth, eighth, and ninth pair of nerves.\n\nTaste is the appreciation of the savour of bodies, or, in other words,\nof certain chemical qualities, which, acting on the nerves, give to our\nmind an agreeable or disagreeable sensation; hence the terms sweet,\nluscious, acid, vinous, sour, bitter, saline, spicy, aromatic, etc.\nSome bodies, however, are tasteless--pure distilled water is tasteless,\nand so would a small globe of glass be, however long it was held in\nthe mouth; but if we put our tongue to a piece of brass, or copper, we\nperceive at once a peculiar flavour, resulting from the oxydized film\non its surface mingling with the saliva covering the nervous papill\u00e6 of\nthe tongue.\n\nThe organs of taste are placed at the commencement of the apparatus\nof nutrition, and their assigned work is to test the quality of the\nfood received, thereby giving warning lest any noxious substance be\nintroduced into the stomach. Man, indeed, employs the sense of taste\nfar less decidedly in this manner than do most other animals; he\nis omnivorous; in the north he relishes train-oil and blubber, the\nblood of seals, and animal food half raw, while, in tropical regions,\nhe feeds upon boiled rice or other grain, seasoned with a little\nspice, and accounts it a luxury. In both cases, the taste is in\nconsonance with the requirements of the system, placed under opposite\ncircumstances. Man, however, acquires by habit an artificial taste,\nand comes at last to relish things which he at first disliked, and in\nmany instances these things are more or less injurious. Nor is this\nartificial taste confined only to man--we have seen it in domestic\nanimals--cats, by nature exclusively carnivorous, will eat boiled\ncabbage with relish; the dog will acquire a partiality for bread and\nbiscuit. On the contrary, some of our herbivorous animals may be taught\nto like animal food. For example, in some parts of Arabia, flesh, raw\nas well as cooked, is occasionally given to the horses, with fragments\nof their owner's meals. An inhabitant of Hamah assured Burckhardt, that\nhe had often given his horses roasted meat before the commencement of\na fatiguing journey, that they might be the better able to endure it;\nthis same person, as we learn from the learned traveller, fearing lest\nthe governor should take from him his favourite horse, fed it for a\nfortnight exclusively upon roasted pork, which so excited its spirit\nand mettle, that it became absolutely unmanageable, and no longer an\nobject of desire to the governor.\n\nIn the Edinburgh Journal of Natural History we find the following\npassage: \"We are assured by M. Yvart, that in Auvergne fat soups are\ngiven to cattle, especially when sick or enfeebled, for the purpose\nof invigorating them. The same practice is observed in some parts of\nNorth America, where the country people mix, in winter, fat broth with\nthe vegetables given to their cattle, in order to render them more\ncapable of resisting the severity of the weather. These broths have\nbeen long considered efficacious by the veterinary practitioners of our\nown country, in restoring horses which have been enfeebled through long\nillness. It is said by Peall to be a common practice in some parts of\nIndia to mix animal substances with the grain given to feeble horses,\nand to boil the mixture into a sort of paste, which soon brings them\ninto good condition, and restores their vigour. Pallas tells us, that\nthe Russian boors make use of the dried flesh of the hamster, reduced\nto powder, and mixed with oats, and that this occasions their horses\nto acquire a sudden and extraordinary degree of _embonpoint_. Anderson\nrelates, in his History of Iceland, that the inhabitants feed their\nhorses with dried fishes when the cold is very intense, and that these\nanimals are extremely vigorous, though small. We also know, that in\nthe Fero\u00eb Islands, the Orkneys, the Western Islands, and in Norway,\nwhere the climate is still very cold, this practice is also adopted;\nand it is not uncommon, in some very warm countries, as in the kingdom\nof Muskat, in Arabia Felix, near the Straits of Ormuz, one of the\nmost fertile parts of Arabia; fish and other animal substances are\nthere given to the horses in the cold season, as well as in times of\nscarcity.\"\n\nIn Norway, or at least in some districts of that country, the cattle\nare housed during the long winter months, and fed partially upon hay,\nbut more plentifully on a kind of diet, which, strange and disgusting\nas we may think it, is said to be much relished. This consists of a\nthick gelatinous soup, made by boiling the heads of fish, and mixing\nhorse-dung with the broth; so that the boat of a Norwegian farmer\nsupplies not only himself and his family with the staple portion of\nwinter subsistence, but his cows also.\n\nWe doubt much whether any wild herbivorous animals will feed upon\npoisonous plants; they are constantly in the exercise of their\ninstinctive faculties, and to these faculties the organs of taste\n(and smell) administer. Hence they constantly reject all that is\ndeleterious. But this is not the case with domestic animals, whose\ninstinct is much enfeebled, or curbed, from the peculiar circumstances\nin which they are placed. Hence accidents often happen, to the great\nloss of the farmer; for example, both horses and horned cattle will\ncrop the foliage of the yew, which offers a temptation to them,\nespecially if underfed, or fed almost exclusively on dry fodder; the\nfoliage of the yew is poisonous. Cattle often perish from eating the\nlong-leaved water hemlock, or cowbane, (_Cicuta virosa_.) \"When Linn\u00e6us\nvisited Tornea, he found a terrible malady sweeping away the cattle\nof the district, and which he at once traced to the long-leaved water\nhemlock. Scarcely, in fact, had he crossed the river, and landed from\nhis boat on the meadow, before he felt convinced of the origin of the\nmischief. This deadly plant grew there in abundance, and it appeared\nthat as soon as the cattle left off their winter fodder, and returned\nto pasturage, they died swollen and convulsed; as the summer came on\nthe mortality decreased, and still more so with the advance of autumn.\n\n\"The least attention,\" says Linn\u00e6us, \"will convince us that brutes\nreject whatever is hurtful to them, and distinguish poisonous from\nsalutary plants by natural instinct, so that this plant is not eaten\nby them in the summer and autumn, which is the reason that in those\nseasons so few cattle die; namely, such only as either by accident or\npressed by extreme hunger eat of it. But when they are let into the\npastures in spring, partly from their greediness after fresh herbs,\nand partly from the emptiness and hunger they have undergone during\na long winter, they devour every green thing which comes in their\nway. It happens, moreover, that herbs at this time are small, and\nscarcely supply food in sufficient quantity. They are, besides, more\njuicy, and covered with water, and smell less strong, so that what is\nnoxious is not easily discerned from what is wholesome. I observed,\nlikewise, that the radical leaves were always bitter, the other not,\nwhich confirms what I have just said. I saw this plant in an adjoining\nmeadow, mowed along with grass for winter fodder; and, therefore, it is\nnot wonderful that some cattle, though but a few, should die of it in\nwinter. After I left Tornea, I saw no more of this plant till I came\nto the vast meadows near Limmingen, where it appeared along the road,\nand when I got into the town I heard the same complaints as at Tornea,\nof the annual loss of cattle, with the same circumstances.\" Monkshood,\nmeadow-sweet, hemlock, (_Conium maculatum_,) meadow-saffron, foxglove,\netc., are occasionally eaten by cows, and prove fatal.\n\nThe sense of taste varies greatly in different animals; in granivorous\nbirds, in reptiles and fishes generally, we cannot suppose that the\nimpressions made on the gustatory nerves are at all delicate; they\nswallow their food entire at a single gulp, and their tongue is\ncovered with a thick or a horny cuticle. Among birds, the carnivorous\ntribes, the parrots, and the swans, and true ducks, possess the sense\nof taste in considerable perfection. Among reptiles, tortoises and\nvegetable-feeding lizards, as the iguana, are, as it would seem,\nsuperior to the others; and among fishes, it is probable that those\nwhich feed on marine or aquatic vegetables, are endowed with a higher\ndegree of taste than those which prey upon other fishes, which they\nengulph at once. It cannot be denied that many insects, as bees,\nwasps, butterflies, the house-fly, and various others, enjoy a keen\nsense of taste, and relish the sweets which prove so attractive to them.\n\nAmong the mollusca, some, at least, are endowed with the sense of taste\nin no low degree; the snail and the slug are examples in point, as the\ngardener can readily testify.\n\nWhat information do we gain by the sense of taste? The eye and the\near conduce to our mental improvement, to our store of knowledge,\nto our appreciation of the sublime and beautiful. Eloquence, music,\npoetry, painting, sculpture, architecture, scenery--the glory of the\nsun, and the moon, and the stars--these appeal to our mind through\nthe organs of sight and hearing; but the sense of taste administers\nrather to our animal than to our intellectual being, and, doubtless,\nthe pleasures of taste contribute greatly to the enjoyments of our\nexistence. Taste, then, belongs to us less as spiritual, intellectual,\nimmortal beings, than as corporeal, mortal beings; nevertheless, it\nis part of our nature, implanted in us by an all-wise God, in order\nthat we should relish the provisions for sustaining life, which he has\nso bountifully provided. To pretend that we are indifferent to the\npleasure or the disgust resulting from taste is an untruth--nay, it\nis to say that God's gifts to us are not worth our consideration. Our\nLord and Saviour was one of a party at a marriage feast, and when the\nwine was exhausted, he turned water into wine, which was superior to\nthat previously passed round. \"This beginning of miracles did Jesus in\nCana of Galilee, and manifested forth his glory.\"[19] But while, with\na healthy appetite we relish our food, giving thanks to God for his\nbounty, let us not be epicures or gluttons; let our moderation be seen;\nlet us use, not abuse, the gifts of our heavenly Father.\n\n[19] John ii. 11.\n\n4. _Smell._--On a fine, filmy membrane, which lines the labyrinth\nof the nasal cavities, are distributed the delicate ramifications\nof the olfactory nerves, or the nerves of smell. These nerves are\nconstructed for transmitting to the mind impressions arising from\nthe floating exhalations of odoriferous substances. It is through\nthese nasal cavities, principally, that man and quadrupeds breathe;\nhence the respiration of the air informs us of our proximity to\nobjects disgusting and noxious, or, on the contrary, attractive from\ntheir fragrance. Surely we need not adduce instances in proof of our\nposition. The scent of putrescent animal or vegetable matters is\nin itself a warning to us to retire from the locality of mortific\ncorruption, and escape from the region of disease. How loathsome\nto our sense are these putrescent effluvia! They nauseate us even\nto sickness--nay, sometimes almost to fainting; indeed, the writer\nhas seen a violent fit of epilepsy produced by the overpowering and\nhorribly disgusting odour of the matter contained in the scent pouch\nof a small quadruped, the grison, (_Galictis vittata_,) which he was\ndissecting, the sufferer being a practical zoologist, accustomed to the\ndissecting-room.\n\nBut when the voice of the nightingale is heard, and the air is loaded\nwith the perfume of the hawthorn blossom, and of thousands of spring\nflowers, are we not invited, as it were by a secret call, to walk\nabroad through woodlands and meadows, contemplating the works of God?\nWe are thus lured to beneficial exercise--to inhale\n\n    \"The breezy fragrance of the morn\"--\n\nto forget the trials of life, and muse upon a still brighter world,\nwhere the flowers perish not, where storms come not, and where winter\nis unknown. Thus, to our bodily health do our senses administer; and\nthus the sense of smell calls us from the close room of the populous\ncity, into the fresh air of the country--from the crowded town,\n\n    \"Where houses thick and sewers annoy the air,\"\n\nto issue forth on a summer's morn, and breathe the pure air redolent of\nsweetest odours.\n\nWhen overpoweringly offensive effluvia disgust us, we endeavour to stop\nour breath--we breathe at protracted intervals, take in as little air\nas possible, and endeavour to escape from the infected locality; but\ndo we flee away from the gale bearing the scent of the honey-suckle,\nthe bean-field, or the new-mown hay? It is, indeed, rather to our\npleasures, to our mental enjoyment, to our delight, or to our disgust\nand abhorrence, that our sense of smell administers. We depend little\nupon it for our discrimination between things acting as poison,\nand things nutritious or wholesome. How pleasant is the smell of\nlaurel-water or prussic acid--how dull and insipid the smell of wheaten\nflour! We must not, then, always be guided by our sense of smell,\nalthough in general it serves us as a monitor.\n\nThe sense of smell is intimately combined with that of taste; indeed,\nit is a powerful auxiliary to it, for, as a learned writer well\nobserves, \"taste, without the aid of smell, would be very vague in its\nindications, and limited in its range.\" Nevertheless, savage people,\nin whom the sense of smell is far more acute than in civilized races,\ndo not appear to possess a greater refinement of taste--indeed, what\nthe former regard as delicacies would be rejected by the latter with\nabhorrence. Most quadrupeds possess the sense of smell in far greater\nperfection than man, and are evidently influenced by it in their choice\nor rejection of food. In the carnivorous tribes this sense is, perhaps,\nat its highest ratio, and many pursue their prey guided by their\nolfactory organs alone.\n\nCertain odours are agreeable to some few animals, irrespective of\nfood; but on this point our range of information is limited. The cat\ndelights in the scent of valerian, and some other herbs, although they\nare not among the articles of this animal's diet; yet to the cat and\nthe dog, the odour of the sweetest flowers yields no pleasure. Birds,\nin general, are endowed with the sense of smell in a far lower degree\nthan quadrupeds, and the olfactory organs are far less developed.\nBirds of prey are guided by their keen powers of vision, and, indeed,\nif we are to trust to the experiments of Audubon, the sense of smell\neven in the carrion-loving vulture, contrary to the opinion of the\nancients, as well as of modern naturalists, is at a low ratio; for, as\nhe asserts, the stuffed skin of an animal will attract a vulture from\nits \"pride of place,\" in the upper regions of the air. It is true that\nthis assertion has been contradicted by Mr. Waterton, but it is again\nconfirmed by the experiments and observations of Mr. Bachman, which\nare recorded in Loudon's Magazine of Natural History, viii. 167; and\nM. Levuillant seems to have considered that it is by the eye chiefly,\nif not exclusively, that the vulture obtains its disgusting food. The\nfollowing observations from the proceedings of the Zoological Society\nwill be here, perhaps, not unacceptable:--\n\nMarch 14th, 1837.--\"A paper was read on the habits of the _Vultur\nAura_, by Mr. W. Sells, with notes of the dissections of the heads of\ntwo specimens, by Mr. R. Owen. The writer states, that this bird is\nfound in great abundance in the island of Jamaica, where it is known\nby the name of _John Crow_; and so valuable are its services in the\nremoval of carrion and animal filth, that the legislature have imposed\na fine of \u00a35 upon any one destroying it within a stated distance of the\nprincipal towns. Its ordinary food is carrion, but when pressed hard\nwith hunger, it will seize upon young fowls, rats, and snakes. After\nnoticing the highly offensive odour emitted from the eggs of this bird\nwhen broken, Mr. Sells relates the following instances which have come\nunder his own personal observation, for the purpose of proving that the\n_Vultur Aura_ possesses the sense of smell in a very acute degree.\n\n\"It has been questioned whether the vulture discovers its food by\nmeans of the organ of smell or that of sight. I apprehend that its\npowers of vision are very considerable, and of most important use; but\nthat it is principally from highly organized olfactories that it so\nspeedily receives intelligence of where the savoury morsel is to be\nfound, will plainly appear by the following facts. In hot climates,\nthe burial of the dead commonly takes place in about twenty-four hours\nafter death, and that necessarily, so rapidly does decomposition take\nplace. On one occasion, I had to make a _post mortem_ examination of\na body within twenty hours after death, in a mill-house completely\nconcealed, and while so engaged the roof of the mill-house was thickly\nstudded with these birds. Another instance was that of an old patient\nand much valued friend, who died at midnight; the family had to send\nfor necessaries for the funeral to Spanish Town, distant thirty\nmiles, so that the interment could not take place until noon of the\nsecond day, or thirty-six hours after his decease, long before which\ntime--and a most painful sight it was--the ridge of the shingled roof\nof his house, a large mansion of but one floor, had a number of these\nmelancholy heralds of death perched thereon, beside many more which had\nsettled in trees in its immediate vicinity. In these cases, the birds\nmust have been directed by smell alone, as sight was totally out of the\nquestion.\n\n\"In opposition to the above opinion, it has been stated by Mr. Audubon,\nthat vultures and other birds of prey possess the sense of smell in\na very inferior degree to carnivorous quadrupeds, and that, so far\nfrom guiding them to their prey from a distance, it affords them no\nindication of its presence even when at hand. In confirmation of\nthis opinion, he relates, that he stuffed the skin of a deer full of\nhay, and placed it in a field; in a few minutes a vulture lighted\nnear it, and directly proceeded to attack it, but finding no eatable\nfood, he at length quitted it. And he further relates, that a dead\ndog was concealed in a narrow ravine, twenty feet below the surface\nof the earth around it, and filled with briers and high canes; that\nmany vultures were seen sailing over the spot, but none discovered\nit. I may remark upon the above experiments, that, in the first case,\nthe stag was doubtless _seen_ by the birds, but it does not follow\nthat they might not also have smelt the hide, although inodorous to\nthe human nose; in the second case, the birds had been undoubtedly\nattracted by the _smell_, however embarrassed they might have been by\nthe concealment of the object which caused it. I have, in many hundred\ninstances, seen the vulture feeding upon small objects under rocks,\nbushes, and in other situations, where it was utterly impossible that\nthe bird could have discovered them but through the sense of smell; and\nwe are to recollect, that the habit of the vulture is that of soaring\naloft in the air, and not that of foraging upon the ground.\"\n\nTo this account are appended the details of a minute comparison, by\nprofessor Owen, of the olfactory nerves and the olfactory branch of the\nfifth pair in the _Vultur Aura_, with those of the common turkey and\nthe goose. The learned anatomist concludes by saying, \"the above notes\nshow that the vulture has a well-developed organ of smell, but whether\nhe finds his prey by that sense alone, or in what degree it assists,\nanatomy is not so well calculated to explain as experiment.\"\n\nIt is far from being impossible that Mr. Waterton and Mr. Wells on one\nside, and Mr. Audubon and his party on the other, may be both correct,\nfor in different species of vulture the power of smell may greatly\ndiffer; we know that it does among carnivorous quadrupeds, which seek\ntheir prey, some chiefly by sight, others by their acuteness of scent.\nAmong reptiles, the sense of smell appears to be at a low ratio, nor\ncan we suppose that it is acute in fishes. In fact, in fishes the\nnasal cavities are rudimental, and do not communicate with the organs\nof respiration. They are nothing more than blind sacs, placed one on\neach side in front of the head, with two external openings appertaining\nto each sac. The principal entrance is valvular, and on a curiously\nplaited membrane in the sac itself, or on tufted or arborescent\nfilaments, are the ramifications of the olfactory nerves distributed.\nThat fishes are attracted or repelled by the odorous effluvia of\nbodies, diffused either through the water itself or through the air\nwhich the water contains, is too well ascertained to be denied. Fishes,\nin fact, are attracted by certain odoriferous substances, and anglers\noften use baits impregnated with some volatile oil.[20]\n\n[20] On this subject see Izaak Walton's \"Complete Angler.\"\n\nWe cannot for a moment doubt that insects smell; that ants and bees\nare greatly directed by this sense in their search after food; that\ncarrion-loving beetles are thereby guided from a distance to their\nrepast; that the flesh-fly is led to putrescent animal substances;\nand we know that the flesh-fly is sometimes deceived by the smell of\ncertain plants emitting a cadaverous odour, and deposits her eggs upon\nthem, the larv\u00e6 perishing for want of proper food. In what organ the\nsenses of smell in insects are placed does not appear very plain, and\nthe like observation applies to the _crustacea_, as crabs and lobsters,\nfor which baited traps are set, and into which they are allured by\ntheir sense of smell.\n\nNo distinct organs of smell have been discovered in the mollusca,\nyet it is incontestable that some of these creatures are capable of\nappreciating odours. We cannot suppose that in the highly-organized\nand savage cuttle-fish this sense is wanting; and we know that snails\nand slugs are attracted from a distance by the odour of the favourite\nplants or fruits on which they feed. The garden slugs are fond of\nanimal food, as we can testify, and they will pick bones with relish;\nwe have seen the hollow of a marrow-bone thrown into the garden filled\nthe next morning with slugs, which had completely cleaned it.\n\nWhether the bivalve mollusks, as mussels, oysters, clams, etc., have\nany definite sense of smell, we cannot ascertain, but we conjecture\nthat they are endowed with the sense of taste, for they know what to\naccept and what to refuse.\n\nWe have said that man derives pleasure or disgust from the exercise of\nthe sense of smell, and is greatly directed thereby what to choose and\nwhat to avoid; yet this sense harmonizes with those of sight, hearing,\nand more particularly of taste, to render this world delightful to\nus, if we use God's gifts aright. Has he not scattered the loveliest\nflowers in garden and meadow? Has he not created fruits that gratify\nalike the sight, the touch, the taste, and the smell? Has he not spread\nthe beauties of nature around us? Was not the garden of Eden prepared\nfor our first parents? Yes; but sin has entered the world, and over\nflower and fruit has been the \"trail of the serpent.\"\n\nA few passages from the Scriptures, on which we need not comment,\nwill serve to show the figurative notice of, or reference to this\nsense by the sacred writers, in order to influence the mind of man\nthrough an appeal to his own sensations. \"An odour of a sweet smell,\na sacrifice acceptable, well-pleasing to God,\" Phil. iv. 18. Works\npleasing to the Lord, deeds of charity and mercy, done by the believer\nas a testimony of his lively faith, and a proof to the world that faith\nengenders good works; such works, and not those of the pharisee, are\nan odour acceptable to God. \"Walk in love, as Christ also hath loved\nus, and hath given himself for us an offering and a sacrifice to God\nfor a sweet-smelling savour,\" Eph. v. 2. Let us, who call ourselves\nChristians, so walk, that our conduct before men may be after the\npattern of Him, who, in love to a fallen race, offered himself as a\nsacrifice fragrant unto God the Father, that we might escape the sword\nof justice. When Noah offered burnt-offerings on the altar, \"the Lord\nsmelled a sweet savour,\" Gen. viii. 21; and to Him even now, O reader,\nwill be fragrant true penitence and faith in that Mediator, of whom the\nsacrifices under the primitive dispensation were but types, and in this\nsense only did they waft incense to the throne of the Almighty! The\nlanguage is altogether figurative; but how pertinent to our feelings,\nand therefore how clear to our understanding, and how forcible!\n\n5. _Touch._--Of all the senses, not one is so important to us as\nthat of tact or touch. It is the foundation, as it were, of all our\nknowledge of the material world, and according to their elevation in\nthe scale of being do animals enjoy this sense in greater perfection,\nand possess organs in which it is more especially concentrated. We\nhere distinguish, between mere feeling and touch. We consider the\nwings of the bat, and the antenn\u00e6 of insects, rather as feelers than\nas organs of exact appreciation. The sense of feeling is diffused over\nthe whole surface of our body; but the sense of touch, so far as man is\nconcerned, resides in the hand, and especially in the pulpy tips of the\nfingers.\n\nIt is true that we use the word feel when we test the qualities of\nbodies with our hands, and in this sense our hands are feelers. But we\nderive a knowledge from the use of our hands, which no other animal\nderives from the exercise of any organ of tact it may possess. Nor\nis this to be wondered at, for in all other animals tact or touch\nadministers only to their physical necessities. For example, the sense\nof touch in the pulpy end of the beak of the snipe or woodcock must\nbe exquisite--multitudinous are the nerves supplying that part--for\neven the soft worm or larva in the oozy ground is felt, and the\nfinger of man would most probably fail here; but in man the sense of\ntouch appeals to the mind, and communicates mental pleasure, mental\ninstruction, or even mental disquietude. Even as discords in music, or\ngrating sounds, such as the filing of a saw, or the rubbing of cork\nagainst a wall, excite the nervous system through the mind, so does the\nsense of touch disturb the mind and body when that which is touched is\ndiscordant. A lady of the writer's acquaintance, by no means timid, and\nby no means afraid of snakes, was induced to let a common snake glide\nthrough her hand; she bore the sensation with firmness, but she nearly\nfainted when the snake had crept through her grasp, and described the\nworking of the reptile's ribs and abdominal plates as communicating\nan indescribable sensation. Yet that snake was a sort of pet, and she\nused to stroke its head, and feel its lambent tongue quiver against\nher hand. She was not afraid, but the sensation jarred like discordant\nnotes.\n\nWere persons to write down their experiences of the pleasing and\nunpleasing sensations derived through the medium of the different\nsenses, and were those notes collected together, we should have a mass\nof most interesting and instructive information, well worthy the study\nof a physiologist. After all, however, the sense of touch or tact gives\nless pleasure to man than that of sight, hearing, taste, or smell; it\nappreciates neither colours nor harmony, nor the flavour of luscious\nviands, nor the odour of flowers and perfumes; but it communicates\ngreatly to his store of information. It is a \"matter of fact\" sense,\nand though an old poet has said--\n\n    \"Have you felt the wool of the beaver,\n    Or swan's down, ever?\"\n\nit is not one of the senses which figure on the page of poetry or\nromance.\n\nWe discriminate, then, between the sense of touch and that of mere\nfeeling. Most probably all animals, even the lowest mollusks,\nfeel,--nay, even animals in which no nerves are to be discovered, as\nthe acaleph\u00e6, or jelly fishes; but touch is a refinement upon feeling,\nwhich is restricted within certain zoological bounds. A learned writer\nsays: \"The conditions on which the perfection of the sense of touch\ndepends are, first, an abundant provision of soft papill\u00e6, supplied\nwith numerous nerves; secondly, a certain degree of fineness in the\ncuticle; thirdly, a soft cushion of a cellular substance beneath the\nskin; fourthly, a hard resisting basis, such as that which is provided\nin the nails of the human fingers; and lastly, it is requisite that\nthe organ be so constructed as to be capable of being readily applied,\nin a variety of directions, to the unequal surfaces of bodies, for the\ncloser the contact, the more accurate will be the perceptions conveyed.\nIn forming an estimate of the degree of perfection in which the sense\nis exercised in any particular animal, we must accordingly take into\naccount the mobility, the capability of flexion, and the figure of the\nparts employed as organs of touch.\"[21]\n\n[21] Dr. Roget.\n\nThis is decidedly true as regards the higher orders of creation; but\nlet us look at insects--do not bees, and wasps, and flies feel? can\nwe watch a fly brushing its head and wings, and rubbing its little\npaws against each other, without an assurance that it enjoys the sense\nof touch? and what shall we say of the spider, that feels at each\nthread, and \"lives along its line?\" Surely its sense of touch must be\nsufficiently acute; yet it is limited to a certain given object, and\nthe spider gains only that information which bears upon its animal\nnecessities. But the sense of touch gives to man a number of the\nproperties of matter, which he retains as abstract ideas, such as\ndimension, form, condition of surface, hardness, softness, elasticity,\ncompressibility, fluidity, quiescence, motion. In many and most\nimportant respects it assists the eye; and, indeed, the senses of sight\nand of touch appear to be correctors and supporters of each other.\nAs in the case of every other sense, accuracy is greatly improved by\nhabit, yet the qualities of matter, under the dominion of touch, are\nascertained in so correct a manner that we are scarcely ever deceived\nby the knowledge thus acquired.\n\nDr. Fleming, in his \"Philosophy of Zoology,\" thus writes: \"The sense of\ntouch appears in man to be able to obtain nearly all the information,\nwith regard to external objects, which it is capable of receiving.\nIn a few instances, the lower animals surpass us in the delicacy of\nthe sense, as the bat, which is warned indirectly by its aid of the\npresence of bodies previous to coming in contact with them. The feelers\nof insects are likewise better adapted for exploring the condition\nof the surface of bodies than any organ which we possess. But in all\nthese the sensibility of touch is limited to particular qualities, or\nconfined within narrow bounds. The human hand, on the contrary, by\nits motions, the pliability and strength of the fingers, and their\nsoftness, is the most extensive and perfect organ of touch possessed by\nany animal.\"\n\nThe accuracy of the sense of touch is greatly improved by habit; and\nwhen its resources are in constant demand, as in the instance of\npersons deprived of sight, or born blind, its discriminating powers\nare wonderfully increased. The same observation applies also to the\nsense of hearing, which in blind persons generally is extremely acute\nand accurate in its perceptions. In a Monthly Volume, published by the\nReligious Tract Society, and entitled \"Comparisons of Structure in\nAnimals: the Hand and the Arm,\" the reader will find a general account\nof the structure and uses of the anterior limbs of man and the lower\nanimals, and of the substitutes for the hand, as an organ of touch and\nprehension, with which many of the latter are provided.\n\nDr. Fleming regards the \"sense of heat\" as distinct from that of\ntouch, and, in fact, as claiming to be one of the senses. \"The sense\nof touch,\" he writes, \"is exclusively occupied with examinations of\nthe conditions of resistance. Contact, therefore, is indispensably\nrequisite for enabling the organ to act upon the object, and muscular\nexertion to examine its condition. Neither of these is necessary to\nenable the sense of heat to act. Caloric rays emanate from a heated\nbody, though at a distance; and in order to ascertain their direction\nand intensity no muscular effort is required. When the heated body\nhappens to be in contact with us, we in like manner examine its\nconditions in reference to temperature without any muscular exertions,\nor, rather, we try to avoid them. Thus, when I lay my hand upon the\ntable to examine its hardness or smoothness, I make an obvious muscular\neffort with my fingers; but when I lay my hand upon the table to\nexamine its temperature, I endeavour to check all motion, so as to\nkeep my hand in the same position. These qualities of the sense of\nheat sufficiently distinguish it from that of touch, with which it has\nbeen confounded, and justify its establishment as a distinct power of\nperception.\"\n\nIt is true that we cannot test caloric by the touch, but it does not\nappear to us that an appreciation of caloric involves any other sense\nthan that of ordinary cutaneous feeling; the feeling of heat or cold\nis a mere sensation, agreeable or painful as circumstances may be,\nand it is natural that we should wish to experience that temperature\nwhich is most congenial to us. We say that marble is cold and wood\nwarm, yet both may be of the same temperature; but the marble produces\na sensation of coolness, because it rapidly abstracts caloric from\nthe part applied to it; the skin is, in fact, a very imperfect\nthermometer, yet sufficient for all ordinary purposes. It conceals\nthe machinery of our bodies, giving beauty of outline and appearance,\nand being provided with a most minute network of nerves of sensation,\nit gives us warning by the pain experienced of what things are to be\navoided. \"A burned child dreads the fire\" is an old saying, and a boy\nwho has been stung by a nettle will not rashly meddle with the plant\nagain.\n\nAll our senses require training and education; they are taught, even\nas we are taught language. It is some time before the infant sees\ndistinctly, or forms any idea of size, proportion, or distance; long\nbefore it hears accurately, and understands a word of speech; longer\nstill before it discriminates between musical notes; it is long\nbefore delicious odours are relished, and long before there is much\ndistinction of flavour in food, for instinct directs the infant to\nits mother's breast, and for many a year sweet viands are chiefly\nacceptable. Habit, exercise, practice, then improve the power and\nacuteness of the senses, but simple feeling is blunted by habit and\nexercise.\n\nIt is, we think, Mr. Lane who tells us, that in Egypt and elsewhere,\npersons who have hoarded wealth are in the habit of inflicting the\nbastinado on themselves, increasing the number of strokes by degrees,\nin order to inure themselves to a mode of extortion of which they\nare constantly in dread. They hope to be able to weary out their\ntormentors, or convince them by endurance of their poverty, and so\npreserve their bags of gold and silver. Idolatrous devotees in India\naccustom themselves to self-inflicted torture, and feel much less than\nwe might suppose; nay, even in our own country, in times of spiritual\ndarkness, when by mortification and penance men hoped to merit heaven,\nhow many have worn a shirt of horsehair till custom had made it no\nhardship! The ancient Britons bore, almost unclothed, the severities\nof winter; and we have read a story, but where we cannot recollect,\nto the following purport:--A North American Indian was asked, how,\nnearly naked as he was, he bore with such ease the summer's heat and\nthe winter's cold; he asked the inquirer, how his face, exposed to the\nweather, endured the changes. My face, said the white man, is hardened\nto it; and I, retorted the red man, am face all over.\n\nWe have said it is long before an infant is in the full use of its\nbodily senses: now with regard to feeling the infant is acutely\nsensitive; but who ever saw a child of a few months old examine the\nqualities of objects by the touch? it cannot even manipulate; it cannot\nuse its hands; it has to learn the art of touch, and to improve by\npractice and the exercise of the mind. For example, some persons will\npass a piece of silk or cloth between their fingers, and tell you its\nquality; and so with respect to other things; this is the result of\nattention and exercise.\n\nNo one is born without the organization necessary for the development\nof the sense of touch, for if the arms and hands be deficient, some\nother part, as the lips or tongue, will take up the function, and this\nalone shows what education effects; but if a person be born deaf, or\nblind, or incapable of taste and smell, (which latter appears to be\nvery rare, if, indeed, the case ever occur,) no other part can supply\nthe loss; but the loss, as far as the sight at least is concerned, is\npartly compensated for by the elevation of the sense of touch; and in\nthis we see the immediate bearing of these two senses on each other.\n\nThe boy born blind, upon whom Cheselden so successfully operated,\nbelieved, when first he saw, that the objects touched his eyes, as the\nthings which he felt touched his skin; consequently he had no idea\nof distance. \"He did not know the form of any object, nor could he\ndistinguish one object from another, however different their figure\nor size might be; when objects were shown to him which he had known\nformerly by the touch, he looked at them with attention, and observed\nthem carefully, in order to know them again; but as he had too many\nobjects to retain at once, he forgot the greater part of them, and when\nhe first learned, as he said, to see and to know objects, he forgot\na thousand for one that he recollected. It was two months before he\ndiscovered that pictures represented solid bodies; until that time he\nhad considered them as planes and surfaces differently coloured, and\ndiversified by a variety of shades; but when he began to conceive that\nthese pictures represented solid bodies, in touching the canvass of a\npicture with his hand he expected to find something in reality solid\nupon it, and he was much astonished when, on touching those parts which\nseemed round and unequal, he found them flat and smooth like the rest.\nHe asked which was the sense that deceived him--the sight or the touch.\nThere was shown to him a little portrait of his father, which was in\nthe case of his mother's watch; he said that he knew very well that it\nwas the resemblance of his father, but he asked with great astonishment\nhow it was possible for so large a visage to be kept in so small a\nspace, as that appeared to him as impossible as that a bushel could be\ncontained in a pint.\"[22]\n\n[22] Phil. Trans., 1728.\n\nIn the Philosophical Transactions of 1826 will be found the account\nof a case by Mr. Wardrop, which is very interesting; it is that of an\nintelligent female of mature age, who was born blind; in her infancy,\noperations were performed on both of her eyes, but they failed, one\neye being irrecoverably destroyed, and the other useless from closure\nof the pupil; on this eye Mr. Wardrop successfully operated: but it\nwas not with joy that objects for the first time were perceived; she\nwas confused by the appearance of a new world, now for the first time\nopened to her sense of sight; hitherto she had known it only through\nthe sense of touch, and touch and sight had still to be reconciled.\n\"On the sixth day, she said that she saw better than she had done on\nany preceding day, but I cannot tell (said she) what I do see; I am\nquite stupid. She seemed, indeed, bewildered from not being able to\ncombine the knowledge acquired by the senses of sight and touch, and\nfelt disappointed in not having the power of distinguishing at once\nby her eye, objects which she could so readily distinguish from one\nanother by feeling them.\n\n\"The next day, on examining with the eye the tea-cups and saucers, and\nbeing asked what they were--I don't know, she replied; they look very\nqueer to me, but I can tell in a minute when I touch them. So with an\norange which was lying before her, she could make nothing of it until\nshe actually touched it. When the experiment was made of giving her\na silver pencil-case and a large key to examine with her hands, she\ndiscriminated and knew each distinctly; but when they were placed on\nthe table side by side, though she distinguished each with her eye, yet\nshe could not tell which was the pencil-case and which the key.\n\n\"In six weeks after the operation, she returned home. At this period,\nshe had learned a great deal; she had acquired a pretty accurate notion\nof colours, but with regard to forms and distance she was still very\nignorant. She had also great difficulty in directing her eye to an\nobject, so that when she attempted to look at anything she turned her\nhead in various directions, until her eye caught the object of which\nit was in search. She still entertained, however, the same hope, which\nshe expressed soon after the operation, that when she got home, her\nknowledge of external things would be more accurate and intelligible,\nand that when she came to look at those objects which had been so long\nfamiliar to her touch, the confusion which the multiplicity of external\nobjects now caused would in a great measure subside.\"\n\nThus, then, it is from an association between the senses that\ncorrectness and precision in any one sense are acquired; and especially\ndo the eye and hand support each other, and supply each other's\ndeficiencies till both have learned their perfect lesson. I can stretch\nmy hand out to any object before me with certainty, so truly does the\neye tell me whether it is within my reach or not, but the eye first\nlearned that faculty from the hand, after long discipline and many\ntrials. Afterwards the eye speaks a silent language to the hand, and\nis understood. Under what merciful circumstances are they placed that\npossess all their faculties and senses! but, alas! how many are there\nthat never dream of thanking a merciful God for his unbounded kindness!\nnay, there are some atheistical materialists who believe, or rather\npretend to believe, that man's exquisite organization, and that of\nanimals and plants, is self-developed--how, they do not condescend to\nexplain; for, granting them their premises, namely, that matter is\neternal--and what then? it must be inert, and neither the laws of\nvitality nor chemistry, involving electricity and galvanism, could\nbe taken on by inert particles--all would be chaotic, did not God\ngovern, arrange, and order all. It is he who has created man, and,\nfallen as man is, he still is an object of God's care; for he sent\nhis well-beloved Son into the world for our redemption, and the time\nis coming in which all nations shall know the Lord, and adore him in\nsincerity and truth.\n\nLike all the organs of our senses, the hands are the instrument of\nwickedness to sinful man; his sense of touch is the inlet of evil. How\nrefined that sense in the adroit pickpocket, but to what an ill purpose\nis it devoted! How dexterous are the hands of the shoplifter, but to\nwhat a wretched course have they been trained! The hand grasps the pen;\nevery stroke is guided by its delicate sense of touch; it obeys the\nmind; and, oh! what dictations from the depraved mind have polluted\nsociety! God has been reviled, Jesus Christ denied, the Holy Spirit\nmocked, and in letters written by hands which the almighty Maker and\nPreserver had endowed so supereminently. Their hands are mouldering;\ndust has returned to dust; but where are the immortal spirits which\ndirected those hands to scatter poison abroad? It is not for us to\ninquire or judge. Let us, ourselves, be watchful, and let our hands be\nclean in the sight of God; let us be diligent in business, serving the\nLord; let us fight the good fight of faith, and lay hold on eternal\nlife!\n\nThough we have described the hand as the great and main organ of touch,\nlet it be understood that it is not the first called into operation.\nThe hand requires rigid discipline; for a long period it is useless\nas an organ of tact; yet, when educated, how perfect, how precise!\nBut it is made what it is by education. Our ideas coincide exactly\nwith those of sir Charles Bell, who thus writes: \"The lips and the\ntongue are first exercised; the next motion is to put the hand to the\nmouth in order to suck it; and no sooner are the fingers capable of\ngrasping, than whatever they hold is carried to the mouth; so that\nthe sensibility to touch in the lips and tongue, and their motions,\nare the first inlets to knowledge, and the use of the hand is a later\nacquirement.\"\n\nAnother passage from the same gifted writer is as follows: \"The first\noffice of the hand, then, is to exercise the sensibility of the mouth;\nand the infant as certainly questions the reality of things by that\ntest, as the dog does by its acute sense of smelling. In the infant,\nthe sense of the lips and tongue is resigned only in favour of the\nsense of vision, when that sense has improved, and offers a greater\ngratification, and a better means of judging of the qualities of\nbodies. The hand very slowly acquires the sense of touch; and many\nineffectual efforts are seen in the arms and fingers of the child,\nbefore the direction of objects or their distance is ascertained.\nGradually the length of the arm, and the extent of its motions, become\nthe measure of distance, of form, of relation, and perhaps of time.\"\n\nThroughout life, the sensibility, as it regards tact, of the tongue\nand lips continues paramount; we can feel the slenderest hair with our\ntongue, which our hands would not appreciate: but, on the contrary,\nsize, form, distance, order, and the general qualities of matter,\ncan only be gained through the hand, after a persevering discipline.\nA blind man may examine a statue with his hands, and pronounce upon\nits excellence; and this fact suggests to us an idea of sir Charles\nBell, who says: \"The knowledge of external bodies, as distinguished\nfrom ourselves, cannot be acquired until the organs of touch in the\nhand have become familiar with our own limbs. We cannot be supposed\ncapable of exploring anything by the motion of the hand, or of judging\nof the form or tangible qualities of an object pressed against the\nskin, before we have a knowledge of our own body as distinguished from\nthings external to us.\" From these remarks we naturally slide into a\ndissertation on a sense, allied to that of touch, but yet different--we\nmean muscular sense.\n\n6. _Muscular sense._--God in his infinite wisdom has constructed all\nliving things, and no doubt there is much yet for the philosopher to\ndiscover in the organization of animal bodies; there is, moreover,\nsomething that he never will understand, namely, life intrinsically\nconsidered, and the manner in which the immortal spirit and the\ndying body communicate with and influence each other. But though\nthese points must ever remain a mystery, still there are those the\nobscurity of which science has to a certain degree dispelled, and it\nwas reserved for a late scientific anatomist to prove to the world,\nthat the nerves of sensation and the nerves of motion are essentially\ndistinct, although interblended together they pervade every muscle.\nHence, as this philosopher observes, (we mean sir Charles Bell,) we\nare sensible of the action of our muscles, because these muscles have\ntwo classes of nerves; and he found that in exciting one of these the\nmuscle contracted, while on exciting the other no action took place.\nThe nerve which had no power to make the muscle contract was the nerve\nof sensation.\n\nContinuing his experiments, he proved that there is a nervous circle\nconnecting the muscles with the brain, that one nerve is not capable\nof transmitting what is called the nervous spirits in two different\ndirections at one instant of time, but that for the regulation of\nmuscular action there is a nerve of sensibility, to convey a sensation\nof the condition of the muscles to the sensorium, as well as a nerve\nof motion for conveying the mandate of the will to the muscles. He\nalso demonstrated, that in their distribution through the body, the\nnerves which possess these two distinct powers of conveying sensation,\nand of exciting the muscles to contraction, are wrapped up, or, as\nit were, woven together in the same sheath, and that they present to\nthe eye the single appearance of one nerve. It was only by examining\nthe nerves at their roots, that is, where they arise from different\ntracts of the brain and spinal marrow, and before they coalesce, that\nthis philosophic anatomist succeeded in demonstrating their distinct\nfunctions. In the face, the nerve of motion passes by a circuitous\nroute, apart from the nerve of sensation, to be distributed to the\nmuscles; and, therefore, the distinct characters of these two nerves\nwere, as sir C. Bell asserts, more easily proved by experiment than in\nany other part of the body.\n\nThe nerves of sensation then feel, or rather recognise, those actions\nof the muscles which are excited through the medium of the nerves of\ncontraction, and these nerves of contraction, as far as the voluntary\nmuscles are concerned, obey the commands of an immaterial being--mind,\nspirit, soul; in the lower animals, so far as we know, this principle\nis transient, for they have no ideas of life, or of death, or of\nfuturity; but in man, the soul is immortal, and for the future bliss of\nthis immortal essence revelation affords a certain guide.\n\nNow the sense of touch and the muscular sense have, by most writers,\nbeen confounded together; hence, we are told that weight is determined\nby touch, but this is erroneous; it is determined by the muscular\nagency and sense, under the dictation of the will. The abb\u00e9 Nollet says\nof touch, that \"it not only puts it in our power to judge of what makes\nan impression upon us, but also of what resists our impulsions.\" Here\nthe sense of touch and the muscular sense are confounded together. The\nagency of touch has nothing to do with weight or resistance; and herein\nwe differ from Dr. Fleming, and agree with sir Charles Bell, by whom,\nindeed, this muscular sense was first demonstrated. To feel, or touch,\nis not to resist or struggle. Laocoon, striving with the serpents,\nresists--his muscular sense is called into action, as is that of the\nwrestler when engaged in a trial of skill or strength; but what has\nmuscular feeling to do with that tact, which distinguishes between\nthe texture of tissues, or the smoothness or roughness of bodies? For\nourselves, we refer the sensations of hardness and softness rather to\na muscular sense than a simple sense of touch; but, as we have said,\nthe sense of touch and the muscular sense, or sense of resistance,\ninter-amalgamate with each other, nevertheless, there is a definite\nmuscular sense of which every one is conscious, and it is by the\neducation of this sense that the infant learns to walk, the man to\nascend the lofty ladder, or traverse the ledge of the precipice. It is\nnot connected with feeling alone, but also with sight; and, indeed, the\nsenses of sight, feeling and support, or resistance, are in as close\nrelationship, as are those of smell and taste. This is exemplified in\nthe fencer, whose muscular sense obeys his eye, and in the artist, who\nstrikes out the bold outline of a figure on the canvass.\n\nThis muscular sense is sometimes called the sense of motion; and\nrightly, because it is a feeling of muscular action; not a feeling\nof extraneous bodies, but a feeling of what passes within ourselves,\nas far as such feeling is permitted (many internal operations go on\nwithout our consciousness)--a feeling of what we do, according to our\nwill, and the permission of God Almighty. Does the uninstructed man,\nwho looks upon and admires a lovely landscape, think about the inverted\npicture on his retina? No. Does the athlete who lifts a great weight\nthink of the biceps, or the deltoid, or the pectoral muscles? No. But\ndoes he not feel, while he strives, while he struggles, while he runs,\nan internal consciousness of action totally distinct from touch?\n\nThis perception is termed by sir Charles Bell the \"muscular sense.\" He\nthus illustrates his idea: \"When a blind man, or a man with his eyes\nshut, stands upright, neither leaning upon nor touching aught, by what\nmeans is it that he maintains the erect position? The symmetry of his\nbody is not the cause. The statue of the finest proportions must be\nsoldered to its pedestal, or the wind will cast it down. How is it,\nthen, that a man sustains the perpendicular posture, or inclines in a\ndue degree towards the winds that blow upon him? It is obvious, that he\nhas a sense by which he knows the inclination of his body, and that he\nhas a ready aptitude to adjust it, and to correct any deviation from\nthe perpendicular. What sense, then, is this? for he touches nothing,\nand sees nothing; there is no organ of sense hitherto observed which\ncan serve him, or in any degree aid him. Is it not that sense, which\nis exhibited so early in the infant in the fear of falling? Is it not\nthe full development of that property which was early shown in the\nstruggle of the infant, while it lay in the nurse's arms? It can only\nbe by the adjustment of muscles that the limbs are stiffened, the body\nfirmly balanced and kept erect. There is no other source of knowledge\nbut a sense of the degree of exertion in his muscular frame, by which\na man can know the position of his body and limbs, while he has no\npoint of vision to direct his efforts, or the contact of any external\nbody. In truth, we stand by so fine an exercise of this power, and the\nmuscles are, from habit, directed with so much precision and with an\neffort so slight, that we do not know how we stand. But if we attempt\nto walk on a narrow ledge, or stand in a situation where we are in\ndanger of falling, or rest on one foot, we become then subject to\napprehension; the actions of the muscles are, as it were, magnified,\nand demonstrative of the degree in which they are excited.\n\n\"We are sensible of the position of our limbs; we know that the arms\nhang by the sides, or that they are raised and held out, although we\ntouch nothing and see nothing. It must be a property internal to the\nframe by which we thus know the position of the members of our body;\nand what can it be but a consciousness of the degree of action,\nand of the adjustment of the muscles? At one time, I entertained a\ndoubt whether this proceeded from a knowledge of the condition of the\nmuscles, or from a consciousness of the degree of effort which was\ndirected to them in volition. It was with a view to elucidate this that\nI made the observations which terminated in the discovery that every\nmuscle had two nerves; one for sensation, and one to convey the mandate\nof the will, and direct its action. I had reasoned in this manner: we\nawake with a knowledge of the position of our limbs; this cannot be\nfrom a recollection of the action which placed them where they are; it\nmust, therefore, be a consciousness of their present condition. When a\nperson in these circumstances moves, he has a determined object, and\nhe must be conscious of a previous condition before he can desire a\nchange, or direct a movement.\"\n\nIn walking, riding, swimming, and other bodily exercises; in writing,\nplaying on the piano, or any other instrument of music, the muscular\nsense is called into activity, and co-operates with the senses of\nsight, touch, etc. Muscular exertion is in itself pleasurable, when\nnot pushed too far; and, indeed, the healthy condition, both of the\nbody and mind, results from muscular exertion, and the alternations\nof activity and repose. The appointment of man, after the fall, to a\nlife of labour, was a judgment tempered by mercy. Man is not destined\nto lead a life of sloth or supineness, but, urged on by his natural\nwants, he cultivates the ground, he tames the wild beast of the forest\nor mountain, he builds houses, he constructs ships, he clothes himself\nwith fabrics, he surrounds himself with the comforts, the decencies,\nthe luxuries of life, and in every work which his hands find to do his\nmuscular sense is in requisition; it is this sense which appreciates\nresistance, which enables us to balance our bodies, to move with\ngracefulness, to run, to walk, to leap, to throw the shuttle with\nprecision, or wield the hammer with skill. It is improved by education;\nthe child learns first to walk, and then to run and leap, and in due\ntime to know its own strength, and also the best mode of employing\nthat strength, without reflecting upon the laws of mechanics, or any\nphilosophic theories. It is evident, then, that we have \"a perception\nof the condition of the muscles previous to the exercise of the will,\"\nand that with respect to the hand, \"it is not more the freedom of its\naction which constitutes its perfection, than the knowledge which we\nhave of these motions, and our consequent ability to direct it with the\nutmost precision.\"\n\nThat the lower animals are endowed with this muscular sense cannot be\ndoubted. It enables the tiger to spring with accuracy upon his prey,\nthe cat upon the mouse, the greyhound in pursuit of the hare when to\nmake the fatal snap, and the horse to leap the fence, which his eye\ntells him is within his power; it teaches the loris to creep upon\nits victim, as slowly but as surely as the hand on the clock-face\ntraverses the dial-plate, and attains the given number; it is\nimmediately connected with instinct, and man, when he steps aside to\navoid a threatened stroke, or raises his arm to parry a blow, puts the\nmuscular sense into exercise.\n\nThe muscular sense is, to use a homely expression, an every-day working\nsense; touch and sight are its prime supporters, and to these in turn\nit lends its aid. Nevertheless, to a certain degree it is independent\nof them; the infant seeks the breast as it were by an instinctive\nimpulse, or applies the coral to its mouth; and in the dark as well\nas in the light, we transmit our food directly and precisely to the\norgans of mastication and deglutition, without thinking upon the manner\nin which the varied actions are performed, or even transiently noting\nthem. We _will_ to perform an act within our power of achievement, and\nby the complicated action of muscles, nerves, vessels, and bones, we\naccomplish our object, at the same time, perchance, we know not the\norigin and insertion of a single muscle, the direction of a single\nnerve, the course of a single artery.\n\nThe muscular sense is, in fact, in perpetual exercise; it is intimately\nconnected with self-consciousness, for we feel that we corporeally\nexist, that other bodies exist around us, that they resist us, that\nthey lead us to calculate our own powers, nor will all the arguments of\nthe school of Berkeley convince us that we exist only in idea. When Dr.\nJohnson stamped upon the ground to disprove Berkeley's idea, he was\nright.\n\nSo much for the senses with which we are endowed, and the information\nwhich the mind receives through their respective channels. They teach\nus all that we know concerning the qualities of matter, and they\nsubserve many of our enjoyments--they are essential to our comfort,\nour activity, our usefulness; but we gain through their medium no\nabstract truths, no determinate principles. These are elaborated in\nthe mind itself by its own self-analysis; but, then, they do not teach\nus our own position as it respects time and eternity. The wisest\nof the heathens of Greece or Rome lived in doubt, entangled in the\nmazes of a vain system of philosophy; and though they might believe\nin a god, or in gods, deducing their arguments as to the existence\nof an all-powerful Being from the works of nature, and from that\ninternal conviction which seems common to the human race--they knew\nnothing of His attributes, of his laws, of his requirements, of man's\nfallen nature, of the intrinsic sinfulness of the heart, of the means\nof grace, of a hope of glory. They could write noble poems, deep\nphilosophic treatises, histories of empires, narratives of events,\ndetails of characters, descriptions of works of art; they could carve\nstatues of matchless perfection, and build temples of surpassing\nsplendour. They displayed an intellectual pre-eminence, which still\nsheds a lustre over the civilized world. Who by searching can find out\nGod? Unless God graciously reveals himself to us, a true knowledge of\nhim in our fallen state is impossible; the capabilities of our minds\nare, after all, but limited; and though, through reflection on the\nevidences of our senses, we may come to the conclusion that there is\nan omnipotent Power, we remain in ignorance as to what that Power is,\nand as to our relationship thereunto. Hence, then, the necessity of\ninformation beyond what the mind can gain through the senses, or by its\nown reflex operations; we are conscious of our position as respects\nthe lower animals, and we have natural longings after and hopes of\nimmortality; the soul whispers to itself, _Non omnis moriar_, I shall\nnot all die; but here, were it not for revelation--a revelation from\nGod, we should be left in darkness.\n\nGod gave a revelation of his will to Adam; our first parents\ntransgressed, but then in mercy a promise was given, that the seed\nof the woman should bruise the serpent's head. God gave a further\nrevelation of his will to Moses, with promises and commands, and\nelected from among the nations a peculiar people, of whom from the line\nof Jesse after the flesh should arise the Messiah; in Him are all the\npromises and prophecies centred, and through him the great revelation\nof God's purposes of mercy to a fallen world was ordained to be\npublished. The Messiah came; He of whom Isaiah prophesied; the despised\nand rejected of men--God manifest in the flesh. The prophet's words\nwere verified, \"He was wounded for our transgressions, he was bruised\nfor our iniquities: the chastisement of our peace was upon him; and\nwith his stripes we are healed.\"[23]\n\n[23] Isa. liii. 5.\n\nThis is the Christian revelation, which, while it shows us our lost and\nsinful nature, our utter unworthiness, and the insufficiency of good\nworks for salvation--whilst it humbles our pride, and self-sufficiency,\nand teaches that our place before God is in the dust, yet it speaks\nof joy and peace, for it points out what is all-important, the mode\nof redemption, the forgiveness of our sins, our adoption as heirs of\nthe kingdom of heaven. \"In this was manifested the love of God toward\nus, because that God sent his only begotten Son into the world, that\nwe might live through him.\"[24] God reveals himself in his works as\na God of wisdom and power; but here he discovers himself as a God of\ntruth, justice, and mercy. He reveals himself as the triune Jehovah,\nthe Father, the Son, and the Spirit, one God for evermore; and he gives\nus a revelation of the plan of salvation. And what is this plan? it\nis one by which justice and mercy are reconciled. \"Without shedding\nof blood is no remission\" of sins. The Son of God, according to the\nDivine promise, took upon himself our human nature, dwelt upon earth,\nsinless, and offered himself up as a sacrifice for sin on Calvary. He\n\"who, being in the form of God, thought it not robbery to be equal with\nGod: but made himself of no reputation, and took upon him the form\nof a servant, and was made in the likeness of men: and being found in\nfashion as a man, he humbled himself, and became obedient unto death,\neven the death of the cross. Wherefore God also hath highly exalted\nhim, and given him a name which is above every name: that at the name\nof Jesus every knee should bow, of things in heaven, and things in\nearth, and things under the earth; and that every tongue should confess\nthat Jesus Christ is Lord, to the glory of God the Father.\"[25]\n\n[24] 1 John iv. 9.\n\n[25] Philippians ii. 6-11.\n\nOf the sacrifice of Christ, the crowning sacrifice, those of the Mosaic\nritual were types or emblems. By his sacrifice the claims of the law\nwere satisfied. What is required of us? Belief in the atonement. \"Jesus\nsaid unto Martha, I am the resurrection and the life: he that believeth\nin me, though he were dead, yet shall he live: and whosoever liveth and\nbelieveth in me shall never die.\"[26] A true, living, justifying faith\nis the gift of the Holy Spirit, who sanctifies and renews the heart of\nthe genuine believer. \"The carnal mind is enmity against God: for it\nis not subject to the law of God, neither indeed can be;\" but when the\nmind is enlightened by grace Divine, the awfulness of sin is perceived\nand deeply felt, true repentance is awakened, love and gratitude to God\nfor every mercy are excited, and the soul is warmed with adoration.\nThen does the converted man become prayerful and watchful; then is he\nzealous in God's cause, and anxious for the conversion of those that\nlive in the darkness of ignorance, and travel along the broad road that\nleadeth to destruction. Then will he be patient and trustful under\ntrials and affliction, and justify God's dealings with man.\n\n[26] John xi. 25, 26.\n\nSuch are the truths revealed by God himself, which through nothing\nbut direct revelation could have enlightened, cheered, animated, and\nguided the human affections and will. Man, as an immortal being, has\nnot been left to himself. True it is, that there are many nations still\nin darkness, and some in the most degraded ignorance. To ask why this\nis so, is to ask the reasons which determine God in his purposes; we\nsee as in a glass darkly, and the deep things of God are hidden from\nour eyes; but we are assured that the time will come when all nations\nshall know the Lord, and Christ shall reign in fulness of glory. Let\nus be thankful if our trust is in Christ, if he is in us the hope of\nglory, for \"eye hath not seen, nor ear heard, neither have entered into\nthe heart of man, the things which God hath prepared for them that love\nhim.\"\n\nWe have sufficiently shown the necessity of a revelation to man\nrelative to things essential to his eternal interest, but of which\nhe could gain no knowledge by his own mental exertions. We know by\ninternal conviction that we are immortal beings; but unguided by\nrevelation, we shall look forward to the future with anxiety, with a\nsort of vague apprehension, but revelation dispels anxiety, and fills\nus with all \"joy and peace in believing.\"\n\nDr. Abercrombie, in his work on the Intellectual Powers, says: \"There\nis thus, in the consciousness of every man, a deep impression of\ncontinued existence. The casuist may reason against it till he bewilder\nhimself in his own sophistries; but a voice within gives the lie to his\nvain speculations, and pleads with authority for a life which is to\ncome. The sincere and humble inquirer cherishes the impression while he\nseeks for further light on a subject so momentous; and he thus receives\nwith absolute conviction the truth which beams upon him from the\nrevelation of God, that the mysterious part of his being, which thinks,\nand wills, and reasons, shall, indeed, survive the wreck of its mortal\ntenement, and is destined for immortality.\"\n\nHow mysterious is the union between mind and matter! how little we\nknow of ourselves! how shallow is our deepest philosophy! We know that\nthe mind is that part of our being which thinks and wills, reasons and\nremembers, but we know nothing of it except from these functions. \"By\nmeans of the corporeal senses it holds intercourse with the things\nof the external world, and receives impressions from them, but of\nthis connexion also we know nothing but the facts; when we attempt to\nspeculate upon its nature and cause, we wander at once from the path\nof philosophical inquiry into conjectures, which are as far beyond\nthe proper sphere as they are beyond the reach of human faculties.\nThe object of true science on such a subject, therefore, is simply\nto investigate the facts or relations of phenomena, respecting the\noperations of mind itself, and the intercourse which it carries on with\nthe external world.\"\n\nIn a philosophic point of view, all our knowledge of the world around\nus is referable to the operations of the mind on the impressions\nconveyed to it through the senses, that is, perception. Nevertheless,\nin point of fact, the knowledge which is acquired by an individual\nthrough perception and mental agency, as reflection, memory, etc.,\nis but a small part of what he possesses; it is to the perception\nand mental labour of others that he owes the great mass of knowledge\nhe is gifted with. Generation after generation has contributed to\naccumulate a store of facts, a treasury of thoughts and reflections,\nto which succeeding generations have added, leaving them as a legacy\nto generations yet to come, who will contribute in their turn to\nthe stock, and bequeath the treasure to their successors. Thus are\nwe enriched by the labour of others, and not altogether by our own\nexperience.\n\nHerein is a wide hiatus between man and the most sagacious of brutes.\nThe brute gains all from personal experience; no generation can build\nupon the foundation left by a preceding generation--but man can; and\nit is no objection to allege, that some races remain in a savage\nstate for ages; they possess the power, the capability, the mental\nconstitution, which the brute does not. Besides, they do improve under\nfavourable circumstances. What were the Anglo-Saxon marauders, our\nown ancestors? Savages. Is England now a savage country? What were\nthe Celtic British in C\u00e6sar's time? Savages. Were they savages when\nthe Romans had held possession of the island for three hundred years?\nNo; they had adopted the arts, the manners, the civilization of their\nconquerors. How this very fact of the capability of man to give and\nreceive knowledge demonstrates his superiority in creation! It is true\nthat the human intellect is limited, and that there are mysteries into\nwhich he cannot penetrate; nor is it needful for his welfare, his\nimprovement, his happiness, his hopes of a joyful immortality, that he\nshould be able to do so. Let him rely on the oracles of God. Mysteries,\nindeed, surround him. How fluently does he talk about matter, yet he\nknows nothing about it, excepting what he gains through his senses; and\nthis knowledge is limited to certain qualities, which may be termed\nprimary and secondary. The primary qualities of material bodies are\nin themselves essentials, namely, solidity and extension. We cannot\nconceive of matter, without an involvement of these two properties. The\nsecondary qualities of matter are colour, texture, temperature, smell,\ntaste, etc., properties which differ in different bodies, and which are\nfluctuating, changeable, uncertain. Of these, and other properties of\nmatter, as motion, sound, lightness, or heaviness, etc., our senses are\nthe external tests, though mind is, in reality, the discriminator.\n\n\"Our first knowledge of the existence and properties of the material\nworld is evidently of a complex nature. It seems to arise from the\ncombined action of several senses, conveying to us the general notion\nof certain essences, which are solid and extended, or possessed of\nthose properties which characterize material things. Without this\ngeneral knowledge previously acquired, our various senses, acting\nindividually, could convey to us no definite notion of the properties\nof external things. A smell, that is a mere odour, for example, might\nbe perceived by us, but would convey nothing more than the sensation\nsimply. It could not communicate the impression of this being a\nproperty of an external body, until we had previously acquired a\nknowledge of the existence of that body, and had come by observation to\nassociate the sensation with the body from which it proceeds. The same\nholds true of the other senses, and we are thus led at the very first\nstep of our inquiries to a complicated process of mind, without which\nour mere sensations could convey to us no definite knowledge.\"[27]\n\n[27] Abercrombie.\n\nHere, then, we conclude. Let us give thanks and praise to that God\nwho has made us what we are--instruments of countless strings, all\nin harmony, the music of which reaches the soul, and in the secret\nrecesses of the mind is there analyzed, reflected upon, compared, and\nstored up as knowledge. We feel, we see, we hear, we smell, we taste,\nwe resist; we are assured of our own individuality; we are conscious of\nour own existence, and we know that all around is external to our own\nindividuality. That sense of individuality is in the mind, and we have\nwithin us the assurance of immortality. Let us look to Him, who is the\nSaviour from an immortality of despair, that at the day of judgment\nwe may be found clothed in his robe of righteousness, the garment of\nsalvation.\n\n\n\n\nCHAPTER IV.\n\n     OBSERVATIONS ON THE AGENCY OF THE SENSES, RELATIVE TO THE UNION\n     BETWEEN MIND AND MATTER; AND ON THE OCCASIONAL IMPERFECTION OF THE\n     BODILY ORGANS OF THE SENSES, WITH THE RESULTS DEPENDING THEREUPON.\n\n\nThat the organs of the senses communicate with the mind, through\nthe mediation of certain mysterious filaments, or thread-like\nbodies, termed nerves, cannot be denied; but the manner in which\nthis communication takes place, the process by which mind receives\ninformation from matter, and the subtle operations which enable matter\nto transfer impressions to mind, are points around which, as it appears\nto us, the great Author of our being has thrown an impenetrable veil.\nIt is true, that, in consequence of certain discoveries relative\nto what the older writers termed \"the nervous fluid,\" discoveries\nwhich almost go to prove that the \"fluid\" is of an electric or\nelectro-magnetic nature, a bold theory has been promulgated, namely,\nthat these electro-magnetic currents not only give an impress to\nthe mind or soul, but are in turn influenced by the agency of the\nimmaterial principle, and that thus the communication between mind and\nmatter is carried on; in fact, that the link which unites body to mind\nis a mysterious agent, which (its name is of little importance) cannot\nbe recognised as belonging to the material world. Where revelation\nleaves a subject untouched, it is, we humbly think, allowable to\ntheorize from facts which science has laid open; but let us remember\nthat, however we may incline to a theory which seems consonant to\nscience, a knowledge of the limitation of our intellectual powers\nshould lead us to cultivate a spirit of humility and candour. It is\nsomething to approximate towards truth; let us, then, be content to\nleave much for a future revelation which science on this earth can\nnever unfold before us.\n\nThe foregoing observations may be regarded as a slight introduction to\na passage on the connexion between the mind and body, well worthy of\nespecial consideration: \"In considering the connexion between the mind\nand the body, it is of the highest importance always to remember that\nthe mind, or rather the being which thinks and wills, is the active\nagent. The body, with all its beautiful and wondrous adaptations,\nonly supplies the means of perception and of acting. Nerve-matter is\nthe evident medium and instrument of the being that perceives and\nacts through it. Physiologists appear to have demonstrated that an\nimponderable principle, akin to electricity, is evolved in the nervous\nsystem, and that currents of this kind are constantly traversing the\ndifferent sets of nerves, according to their office and function,\neither as the medium of sensation, volition, or of vegetative life.\nThere is, in short, an action going forward in all the nerves and their\ncentres similar to the electro-magnetic, and, consequently, every nerve\nis polarized. The soul appears to operate upon these electro-magnetic\ncurrents, and to be impressed by them. The _imponderable energia_\npassing in these currents, is apparently the medium between the soul\nand the more palpable materials forming the body. This may be inferred\nfrom the fact, that whatever alters the force of these currents,\nalters the condition of the mind in relation to the body. Thus, the\narrest of the current in a nerve, subservient to voluntary muscular\naction, whether by chemical or mechanical means, prevents the mind\nfrom exercising will in the use of the muscle, with which the nerve\nexperimented on is connected. The same occurs, also, in the like case\nwith any nerve through which we obtain sensation of the presence of any\nbody, which, in a natural state, would so affect the body as to produce\nfeeling.\n\n\"Another evidence that the soul acts through this fluid is afforded in\nthe circumstance, that by strongly directing the attention to any part,\nas, for instance, the eye, a new sensation is perceived in the organ;\nand if this kind of attention be persisted in, or frequently repeated,\nthe eye becomes inflamed and painful. It is also evident, that those\nnerves which belong to parts, the natural functions of which latter\nare carried on without our consciousness, such as the stomach, may be\nrendered sensitive by a strong action of the will; and the operation\nof all the reflex, or ordinary involuntary system, is modified by\nmental emotion. In fact, every thought changes the nerve current.\nMoreover, the brain itself, and all the nerves connected with it, are\nso far influenced by the will of the individual, as to be not only\ndirected into new modes, so as to effect an entire alteration in the\nhabit of mental and muscular action, but also to such a degree, that\nthe completely organized brain is partly a creation of self-directing\nand self-repeating mental activity. It is, so to say, developed by the\nhabits of the soul. How necessary, then, is early training! as we bend\nthe twig so is the tree inclined--a trite axiom, but, nevertheless,\nvery true.\n\n\"The rapidity of the mental processes seems to require an electric,\nor some similar medium, by which they may be effected in connexion\nwith the body, since they result so instantaneously, that the will\nto move, for instance, and the motion, are simultaneous. Professor\nWheatstone has proved, that electricity, like light, travels at the\nrate of 192,000 miles in a second, and this appears to be an agency\nsufficiently subtle to answer all the purposes of the soul as an active\nbeing. Probably electricity and light are but one agent, acting under\ndifferent relations. It is interesting to consider ourselves, by\neach act of our will, as operating upon embodied light; but whatever\nbe the immediate agency between mind and muscle, it is vastly more\ninteresting to know, that willing being is something as really and\ndistinctly existing as the light itself, but in its nature infinitely\nmore subtilely and exquisitely constituted, since it is indivisably and\ninscrutinably associated with the Being who said, Let light be, and\nlight was!\"\n\n\"If we advance further in contemplating our mental existence with\nthe body, we shall more clearly perceive that the body itself is not\nthe cause, but the instrument of mind. In order that it should be a\nready instrument, it is, as we see, constructed on electro-magnetic\nprinciples, so that it serves the purposes of the mind in many\nspontaneous actions, without even awakening consciousness. Whatever is\nessential to the processes of life is carried on in the economy without\nour consent; and until some demand is made by the body, requiring\nour voluntary interference for the removal of inconvenience, or the\nsupply of aliment, our attention is not so far attracted to the body\nas that our desires are distinctly perceived to arise from its state.\nThus, we feel hunger or thirst, and use means for their removal. But\nour emotions and affections are at all times influenced by bodily\ncondition, and in many respects may be traced to a physical origin.\nThey are so far involuntary, that their causes are in operation before\nwe are aware, and they are apt to evince their power against our\nwills; yet reason is tested by their presence, and she prevails over\nthem, in proportion to the clear perception and experience of spiritual\nmotives, or those moral convictions which arise from religious\nenlightenment. Were it not that our connexion with the body subjects\nus to feelings against which we are conscientiously and reasonably\nrequired to contend, we should be incapable of that self consciousness\nby which we distinguish ourselves from our bodies. In fact, those who\nfind no other inducement to thought and action than the body affords,\nare really incapable of apprehending any other than bodily existence,\nand they live not according to spiritual but sensual motive.\"[28]\n\n[28] Dr. George Moore.\n\nGranting the truth, or the approximation to truth, of the foregoing\ntheory, it is evident, not only that whatever alters the force of\nthe electro-galvanic currents of which the nerves are conductors,\nalters the condition of the mind in relation to the body, thus making\nimpressions weaker or stronger; but that whatever deranges the tone or\n\"_timbre_\" of the nerves themselves, produces mental illusions which\nare sometimes of a temporary, sometimes of a permanent character. For\nexample, in derangements of the digestive organs, partial loss of sight\nin one or both eyes, the appearance of black motes, specks, or flies\nfloating in the atmosphere--coloured wavy lines or zigzags--nay, even\nstrange faces, sometimes grotesque, sometimes terrific, palpable to\nvision like the air-drawn dagger of Macbeth, are by no means unfrequent\nphenomena.\n\nBut, besides these transitory effects of nervous derangement, there\nare others dependent upon a permanent condition of the nerves, which\nis not well understood. For example, some persons are incapable of\ndistinguishing between certain colours, while at the same time there\nis no defect in the construction of the eye, as an optical instrument.\nSir J. Herschell examined the eyes of a person affected with this\npeculiarity, and satisfied himself that all the prismatic rays had the\npower of affecting them with the sensation of light, and of producing\ndistinct vision. Hence, therefore, as he observes, \"the defect\narises from no insensibility of the retina to rays of any particular\nrefrangibility, nor to any colouring matter in the humours of the\neye preventing certain rays from reaching the retina, as has been\ningeniously supposed, but from a defect in the sensorium, by which it\nis rendered incapable of appreciating exactly those differences between\nrays on which their colour depends.\"\n\nThe degree of defect in these singular cases is variable, nor are the\ncolours which the sensorium cannot appreciate by any means always\nthe same. Generally, however, red and green are the colours which\nare not discerned, while blue and yellow seldom fail to make a due\nimpression. Seebeck, on somewhat vague grounds, as we think, divides\npersons labouring under this defect of vision into two classes. The\nfirst consists of individuals who have a very imperfect power of\ndistinguishing the impressions of colours generally; in these, at\nthe same time, the defect is greatest with regard to red and green,\nthese colours being not distinguishable from grey; blue is imperfectly\ndistinguished, and yellow the most perfectly.\n\nThe second class consists of individuals who err with regard to the\ndistinction of red from blue; and who, as in the first class, recognise\nyellow the best. It is not, as we have said, to the eye itself that\nwe are to look for the cause of this defect, but to some mysterious\npeculiarity of the sensorium, or to some want of harmony between the\nbrain and the optic nerves; but whether the failure is in the energia\nof the optic nerves, or in the sensorial power of the brain, we pretend\nnot to say. We have, in fact, in this instance, as in so many others,\nonly to confess our ignorance. It is scarcely needful for us to add,\nthat this visual defect is irremediable.\n\nBut there are defects of vision dependent upon the structure of the\neye itself, as an optical instrument; and under this head we may first\nnotice _myopia_, or _near-sightedness_. _Myopia_ results from an\nover-refractive condition of the eye, the rays of light passing from\nany object being brought to a focus in the vitreous chamber of that\norgan, before reaching or impinging on the retina. In this case, either\nthe cornea or the crystalline lens is too convex, or both are in this\ncondition, or the humours of the eye generally are too dense or too\nabundant, and the pupil is large. Persons thus affected see all objects\nindistinctly which are viewed at the ordinary distance of distinct\nvision, but objects held close to the eye are seen with microscopic\naccuracy. The distance from the eye, when in a normal state, at which\nobjects are surveyed with the utmost distinctness, is from fifteen\nto twenty inches. An eye which cannot discern objects with ease and\naccuracy beyond ten inches, may be considered as myopic; but not\nunfrequently persons affected with myopia cannot regard an object with\ndistinctness which is beyond four, three, two, or even one inch distant\nfrom the eye.\n\nTo myopic persons, objects brought within their sphere of vision appear\nmagnified; a small type is read more easily than a large type; and,\nindeed, such eyes see better through a pin-hole in a card than when\nnot thus assisted; the reason is, that the pupil, from its dilatation,\nadmits too many rays of light, but by diminishing the aperture through\nwhich the rays of light are admitted, all but those which are the most\ndirect are excluded, and the images on the retina will be, therefore,\nthe more defined. On the same principle, myopic persons, when\nendeavouring to see distant objects, half close the eyelids, (hence\nthe term myopia, from \u03bc\u03cd\u03c9, I shut, and \u1f64\u03c8, an eye.) Myopic persons\ngenerally see better in the dusk, or at twilight, than others; and\ntheir sight, though short, is strong and good, often lasting. It has\nbeen asserted, that as the eye flattens in age, the vision of myopic\npersons will improve as they advance in life, and the theory, it must\nbe acknowledged, seems feasible, but experience proves that this is not\nthe case; indeed, it would appear that the myopia rather increases than\ndiminishes.\n\nConcave glasses greatly assist the myopic eye; they cause a divergence\nof the rays of light before entering the pupil, and thus counteract the\nover-refractive condition of that organ. The degree of concavity best\nsuited to particular cases can only be determined by trials.\n\nFrom _myopia_ we pass to its opposite, _presbyopia_, or\nfar-sightedness, (\u03c0\u03c1\u03ad\u03c3\u03b2\u03c5\u03c2, old, \u1f64\u03c8, the eye,) this being a state of\nvision to which old age is so commonly subject. In presbyopia the\nrefractive powers of the eye are feeble; that is, the rays of light are\nconcentrated into a focus beyond the retina, and, therefore, too far\nback for the reception by the latter of a definite impression, at the\nordinary distance, of normal vision. This condition may result from\nflatness of the cornea, from an insufficient convexity of the lens,\nor from a shorter degree than natural of the antero-posterior axis of\nthe eye itself. The pupil is more or less contracted. The far-sighted\nperson either removes the object under examination further than is\nusual from the eye, or he avails himself of convex glasses, the effect\nof which is, to increase the refraction, or convergence of the rays of\nlight, before they enter the pupil. Although this condition of the eye\nis common in elderly or aged persons, we are not to suppose that it is\nconfined to such alone. In aged persons it is one of those signs which\nbid man prepare for his last mortal change--a change, the premonitory\nwarnings of which are beautifully described in the twelfth chapter of\nEcclesiastes. But this affection sometimes occurs in the young; for a\ntime it will remain stationary; but after a certain period, determined\nby various concomitant influences, it will greatly increase, till at\nlength, indeed, it may be said, \"those that look out of the windows be\ndarkened.\"\n\nAnother defect of vision may be next noticed; namely, _diplopia_,\nor double vision. This arises from various causes, some of them\nobscure, and, perhaps, connected with a morbid affection of the base\nof the brain, such as a tumor pressing on the _motor oculi_ nerve,\nan inflammatory condition of the brain and its membranes, or a\nsanguineous or serous effusion involving the origin of the third pair\nof nerves. It is often the accompaniment of squinting or strabismus,\nin which, although there is a want of correspondence in the movements\nor position of the two eyes, the vision of each singly is perfect.\nSometimes, however, double vision occurs in one eye only, while, at\nthe same time, there is no disturbance, as far as the harmony of the\nmovements of the two eyes is concerned; occasionally, both eyes are\naffected by diplopia. In these cases, there must be some irregularity\nof refraction, either in the cornea or the lens.\n\nM. Pr\u00e9vost, who published an account of his own case, in the \"Annales\nde Chimie et de Physique,\" 1832, thought that the diplopia under\nwhich he laboured might arise from a fracture, bruise, or partial\nflattening of the lens, or from a separation of its lamin\u00e6. Professor\nAiry and Mr. Babbage both experience the inconvenience of diplopia; in\nthe case of the latter, both eyes are defective, but he can obviate\nthe defect by looking through a small hole in a card, or through a\nconvex lens. \"Professor Airy finds that his eye refracts the rays to\na nearer focus in the vertical than in the horizontal plane, and he\nhas ingeniously contrived to remedy it by the use of a double concave\nlens, one surface of which is spherical and the other cylindrical. The\nspherical surface is to correct the general effect of a too convex\ncornea; the cylindrical is to converge or diverge those rays at right\nangles to the axis; while the parallelism of those which impinge upon\nit in the plane of its axis is unaffected. Thus the focus of the\nspherical surface will remain unaltered in one plane, but in the other\nit will be changed to that of a lens, formed by it and a spherical\nsurface of equal curvature with the cylinder. With the aid of a glass\nof this description, professor Airy could read the smallest print at a\nconsiderable distance, equally as well with the defective eye as the\nsound one. He found that vision was most distinct when the glass was\npretty close to the eye, and the cylindrical surface turned from it.\nWith these precautions, he observes, I find that the eye which I once\nfeared would become quite useless, can be used in almost every respect\nas well as the other.\"\n\nThese are defects in vision which, however distressing, and in\nthemselves, that is, as far as the eye itself is concerned, incurable,\nmay be borne with resignation or remedied by scientific agency. But\nhuman beings are often called to still greater trials--to total loss\nof sight--in other words, to perfect blindness. This calamity results\nfrom many causes; for example, the cornea may become so opaque as to be\nincapable of transmitting rays of light into the interior chamber of\nthe eye; or the crystalline lens, also, may become opaque (_cataract_;)\ndisease of the iris, attended by closure of the pupil, will produce\nblindness, as will also paralysis, or loss of energy, in the retina or\noptic nerve, (_Amaurosis_ or _Gutta serena_.) Accidents may destroy the\npowers of the eye, and a flash of lightning may produce _Amaurosis_;\nthere are, besides, other causes of loss of vision, into which it is\nnot requisite that we should here enter. In certain cases, blindness\nis congenital, that is, the individual was born blind, but in most\ninstances blindness comes on at various periods of life, subsequent\nto the age of infancy. Great as is the calamity of blindness, it is\nnot, we think, so heavy an affliction as total deafness. Privation of\nsight does, indeed, close one avenue leading from matter to mind, but,\nperhaps, not the most important avenue; we may assume this fact--had\nEuclid been blind he could still have written on mathematics.\n\nHomer and Milton were both blind, and had Shakspere been blind, the\nextraordinary creations of his genius would have been what they\nare--the visions of mighty intellect. An admirably written passage in\none of our periodical publications may be here introduced; it proves\nthat blindness closes but a small inlet to the immortal soul: \"We are\nall familiar with many well-authenticated instances of blind persons\nhaving attained to a distinguished position both in literature and\nscience. The celebrated Saunderson, who filled the chair of Newton\nin the University of Cambridge, lost his very eye-balls by the\nsmall-pox, when only twelve years old; yet before he was thirty, we\nfind him giving public lectures on _optics_, explaining clearly the\ntheory of vision, and discoursing admirably on the phenomena of light\nand colours--thus furnishing by his own extensive acquirements a\nconvincing proof of the extraordinary powers of language, and of the\nfull efficiency of the ear, as an avenue to the mind. The darkness of\nthe blind, such as instances like this sufficiently show, is but a\nphysical darkness; they still possess a ready channel, through which\nthe brightest beams of intellectual light may be freely poured: but the\ndarkness of the deaf mute is a mental and moral darkness; and though he\ncan gaze abroad upon creation, yet it is little more than mere animal\ngratification that he feels; he looks not through nature up to nature's\nGod, nor does he participate in that high communion which, through\nthe sublimity of her visible language, she holds with the soul of an\nenlightened being.\n\n\"The reason why the blind usually receive from us a deeper sympathy\nthan the deaf, is, perhaps, because the amount of privation borne by\nthe former can be more accurately estimated. We have only to close our\neyes, to shut out for a while the glorious light of heaven, in order\nto conceive how great that privation must be, but we can never for a\nmoment occupy the place of the uneducated deaf and dumb; we cannot shut\nout our moral and intellectual light; we cannot dispossess our minds\nof all that language has conveyed there, nor realize by any effort of\nimagination the melancholy condition of a being grown up in the midst\nof society, yet deprived of all power of social intercourse; whose\nmind has never been elevated by a single act of devotion, nor soothed\nand comforted by a single impulse of religious feeling. Man naturally\n'looketh on the outward appearance;' and when we see the bright eye,\nand the contented, and even joyous aspect of the deaf mute, we forget\nthat we may witness all this in the brutes that perish.\"\n\nThe ear has been happily called the vestibule of the soul, and the\nannals of the blind who have become illustrious confirm the remark, for\nthey show that few intellectual studies are inaccessible to them. It\nhas even been said, and the assertion has received a kind of universal\nassent among those who have associated much with the blind, that in\ncertain instances they have a facility which others rarely possess. We\nwould not go so far as Huber, who praised the advantages of blindness,\nbut for which, as he says, he might never have become celebrated; nor\nas Holman, who has endeavoured to make it appear, that in his blindness\nhe possesses advantages over those travellers who have the use of their\neyes, most of whom, as he intimates, though they have the use of these\norgans in perfection, yet \"see not.\"\n\nHuber and Holman availed themselves of the eyes of others, and in this\ncapability the blind have great advantages over the deaf, for their\nintercourse with the outward world by means of speech is direct, hence\nthey obtain a knowledge of things, theories, and events, which have\npassed or are passing, of their condition as men, of the requirements\nof God, and of the appointed mode of salvation. The deaf and dumb\n_see_, indeed, all that passes within their immediate sphere, but,\nowing to the imperfect and circuitous mode of communication, (by\nsigns,) by means of which alone access to their mind is gained, little\ndefinite information relative to things, events, their condition as\nfallen creatures, the mode of salvation, and regeneration by the\ninfluence of the Holy Spirit, can be communicated. They imitate, as we\ncan testify, the actions of those who attempt to enlighten them; they\nkneel, they raise the eyes, they mimic a solemnity of deportment, and\nmuch more, so as to persuade some that they have a clear perception of\nspiritual truths; but \"faith cometh by hearing,\" and though we would\nnot presume to assign a limit to God in illuminating the darkest mind,\nyet we doubt whether the soul can in this life become the recipient of\nthe truths and promises of the gospel in all their glorious fulness.\n\nDeaf and dumb persons are generally irascible, impatient, suspicious,\nand watchful; they creep about stealthily, and take you by surprise;\nthey form habits to which they adhere with unflinching pertinacity, and\nfret if any trifle molests them. They may attain to a certain degree\nof cleverness, as the word is usually understood, but we know not any\ndeaf and dumb persons (as far as records go) who have attained to any\ngreat degree of eminence, even under circumstances favourable to the\ndevelopment of their powers. But with regard to the blind, they have\nenriched the arts, the sciences, and literature, by their successful\npursuits, and not unfrequently under circumstances of extraordinary\ndifficulty. Viewing both these classes of men as devoid of education,\ndependent upon themselves for support, and for the enjoyment of life,\nthe blind are physically greater objects of compassion than the\ndeaf, because, without peculiar modes of education, suited to their\nprivation, they cannot obtain a livelihood; but so far as happiness is\ndependent upon knowledge, (and from this source some of the purest\nenjoyments arise,) they are nearly on a level with ordinary men.\nThrough the ear they can acquire knowledge of the highest order, but\nthe case of the deaf is the reverse of this. They are not physically\nso dependent as the blind; for, having the advantage of sight, they\nmay acquire by application the simpler imitative arts, and thus earn a\nsubsistence; but mentally, their great inferiority, their ignorance of\nthemselves, of all that bears upon the concerns of their existence, and\nupon the condition, order, changes, and phases of things extraneous to\nthemselves, is painfully palpable to every philanthropic observer of\nhis fellow-beings. The light of the _eye_ is theirs, but the light of\nthe _mind_ is exchanged for darkness.\n\nWe have already intimated, that the obliteration of one organ of\nsense tends to the greater perceptibility or acuteness of others.\nThis follows almost of necessity, because the loss of any given organ\ntends to the more finished education of those which are destined to\naid it. Thus, in a blind man, the hearing is generally more than\nusually acute and accurate, as is also the sense of touch; while,\nat the same time, the muscular sense is surprisingly elevated.\nBlind guides have been known and celebrated for their extraordinary\ngifts in the wildest moorland and hilly districts. John Metcalf, of\nKnaresborough, (1717,) was road surveyor and contractor in the Peak\nof Derbyshire; he built bridges over rivers, and projected roads over\nthe ridges of the Pennine chain, nor was he less remarkable for feats\nof daring, such as hard riding, swimming, etc. This person was blind\nfrom infancy. How wonderful is the elasticity of the human mind,\nwhich can reconcile itself in such an astonishing manner to the most\nadverse circumstances, and triumph, as it were, over the loss of that\ninestimable possession--sight! Many men of note, who were either born\nblind, or had lost their sight at an early period, have figured in the\nscientific, literary, and musical worlds. A few of these may be here\nmentioned (without going back to long past centuries, that is, to the\ndays of Homer, or Diodatus, or even to the more recent time of Henry,\nthe minstrel of Scotland, born blind 1361, or of sir John Gower, of\nLondon, who died in 1402.)\n\nTake, by way of example, the following:--Huber, the naturalist\n(Geneva, 1784-85); he became blind at the age of seventeen; he wrote\non the labours and instincts of bees and ants, and also on education.\nFrancis Potter (London, died 1678); he wrote on mechanics, theology,\nand painting. F. Carulhi (Nantes, died 1789); born blind; he wrote on\nmusic. Rev. J. Troughton (Coventry, died 1681); blind at four years\nof age; he wrote on theological subjects. John Stanley (London, died\n1781); blind at two years old; a musical performer and composer; he\nwrote the oratorios, Jephthah, Zimri, etc. John Gough (Kendal, 1757);\nblind at the age of three years; a writer of several communications\nto the Manchester Society, and to Nicholson's \"Journal on Botany and\nNatural Philosophy.\" Sir John Fielding (Westminster, died 1780); blind\nfrom youth; police magistrate, and author of the \"Universal Mentor.\"\nJohn McBeath (Dalkeith, died 1834); blind at an early age; he studied\nmusic and mathematics, and wrote on \"Inventions for the Blind.\" He\nwas a blind teacher in the Edinburgh school. James Wilson, author of\nthe \"Biography of the Blind.\" James Holman, whose published travels\nthrough many portions of the world have excited very general curiosity\nand interest. Alexander Rodenback, member of the Belgian Chamber of\nDeputies, and one of the principal actors in the Belgian revolution;\nhe was a supporter of the democratic party, and often made the chamber\nring with his original and eloquent speeches.\n\nWe might add greatly to this list, but we select the above merely as\nexamples, to show how, when the acquisition of knowledge is debarred at\nthe entrance of the eye, the mind will collect it through the inlet of\nother senses. Of the numerous schools of instruction for the blind, of\nwhich our country may well be proud--of the systems of training pursued\nin them--of the labours of pious individuals, some themselves blind--it\nis not our place here to speak. We devoutly pray that the blessing of\nthe all-seeing God may be with them and upon them!\n\nBlindness is sometimes, but, we are happy to say, not very often,\naccompanied by deafness--utter deafness. Blindness is a sad calamity;\nbut when blindness and deafness meet in the same object, what a\ndeplorable picture presents itself to every feeling heart! Blind, deaf,\nmute! Christian reader, reflect--by what means, by what process, shall\naccess be gained to the undying mind? How can we, by human means,\ninstil into the soul the glad tidings of salvation, demonstrate the\ncorruptness of human nature, the necessity of a new birth, the efficacy\nof prayer, and the perfections of the triune Jehovah? Think of an\nimmortal soul imprisoned in such a rayless, silent tenement, debarred\nfrom all acquaintance with the world around, except as far as feeling\nmay go, and taste and smell. But God often works in a mysterious way,\nand perhaps communicates light to the mind, when the visual orbs\nare sealed up in darkness, and the invitations of Christ cannot be\nheard from the lips of his pious minister--the good shepherd, who is\ncommanded to care for the little ones of the fold. Oh! how thankful\nto our gracious God ought we to be, for the full use of all our\nsenses--those inlets to the knowledge either of good or of evil, nay,\nof both; but let us say, \"I and my house will serve the Lord!\"\n\nThe following account is condensed from the \"American Annals of\nEducation,\" and from captain Basil Hall's \"Travels in North America.\"\nIt refers to the deeply touching and most interesting case of Julia\nBrace, a deaf, dumb, and blind American girl, who resides in the\nInstitution for the Deaf and Dumb at Hertford, Connecticut: \"Julia\nBrace was seized with typhus fever at four years of age; during the\nfirst week of her illness she became blind and deaf; she retained her\nspeech for about a year, (the tongue acting mechanically, according\nto acquired muscular habit,) frequently repeating her letters, and\nspelling the names of her acquaintance; but she gradually lost it,\nand seems now condemned to perpetual silence. For three years she\ncontinued to utter a few words; one of the last was 'mother' (that\nword clung to her tongue; it was the earliest she heard and spoke, and\nthe last that died on her lips!) At first she was unconscious of her\nmisfortune, and imagined that a long night had come upon the world.\nAt length, in passing a window, she felt the sun shining warm upon\nher hand, and she made signs indicating she was aware of it; she was\ngoverned by her mother, by means similar to those employed in the case\nof Mitchell. At first she was exceedingly irritable, but she became\nat length habitually mild, obedient, and affectionate. At nine years\nof age she was taught to sew, (wonderful the conjunct operation of\nthe nerves of sensibility and muscular sense!) and since that time to\nknit. Julia Brace, who is now nearly thirty years of age, is supported\nin the Hertford Asylum, in part by the contributions of visitors,\nand in part by her own labours in sewing and knitting. A language of\npalpable signs was early established as a means of communication with\nher friends; this has been much improved by her intercourse with the\ndeaf and dumb, and is now sufficient for all ordinary purposes. It is\nobvious, that her means of perceiving external objects are the smell,\nthe taste, and the touch. The touch is her chief reliance, and enables\nher to distinguish every object with which she has been familiar,\nsometimes by the aid of her lips and tongue; but her smell also is\nsurprisingly acute, and often enables her to ascertain facts which\nare beyond the reach of other persons. Her countenance as she sits at\nwork exhibits the strongest evidence of an active mind and a feeling\nheart, and thoughts and feelings seem to flit across it like the clouds\nin a summer sky. A shade of pensiveness will be followed by a cloud\nof anxiety or gloom; a peaceful look will perhaps succeed; and not\nunfrequently a smile lights up her countenance, which seems to make one\nforget her misfortunes. But no one yet has penetrated the darkness of\nher prison house, or found an avenue for moral or intellectual light.\"\nBlindness alone is a great calamity. Milton most affectingly deplores\nhis deprivation:--\n\n    ------------\"Not to me returns\n    Day, or the sweet approach of ev'n or morn;\n    Or sight of vernal bloom or summer's rose;\n    Or flocks, or herds, or human face divine,--\n    But clouds instead, and ever during dark\n    Surround me, from the cheerful ways of men\n    Cut off; and for the book of knowledge fair\n    Presented with a universal blank.\"\n\nThere are two morbid conditions of the eye of which we ought not here\nto omit, at least, a passing notice; we allude to _hemeralopia_,\n(\u1f21\u03bc\u03ad\u03c1\u03b1, the day, \u1f04\u03bb\u03b1\u03bf\u03c2, blind, and \u1f64\u03c8, the eye;) or, in other words,\nday-blindness; and to _nyctalopia_, (\u03bd\u1f7a\u03be, the night, and \u1f64\u03c8, the eye,)\nthat is to say, night-blindness. We may observe that many modern\nwriters, as Scarpa, and others, have reversed the plain meaning of\nthese terms, and have considered _hemeralopia_ as denoting sight during\nthe day, and blindness during the night; and _nyctalopia_ as expressing\nthe power of vision by night, but not during the hours of daylight.\nIn order to prevent any confusion or misunderstanding, we shall drop\nthe scientific terms, which by some are so strangely misconstrued, and\nadopt their English equivalents. Perfect day-blindness, or owl-sight,\nas the French call it, is of rare occurrence. Dr. Hillary never met but\nwith two examples; at the same time he notices a report, that there\nare a people in the East Indies, and also in Siam, who are subject to\nthe disease of being blind in the day-time, yet who see clearly by\nnight.[29]\n\n[29] Mod. Univ. Hist. vol. vii.\n\nDay-blindness most probably never occurs as a separate disease; it is\nimmediately the result of a peculiarly irritable state of the retina,\ninsomuch that the stimulus of daylight cannot be borne; and not of the\nretina only, but of the iris also, which, in order to exclude the rays\nof light, closes the pupil of the eye to a mere point. All have heard\nof those singular beings termed _Albinos_.\n\nAlbinos are found among all nations, and are noted, from contrast of\ncolour, in African and not unfrequent among the dark tribes of Africa;\nindeed, it would seem that there are families of negroes in which there\nis an hereditary tendency to the production of Albino children.[30]\n\n[30] See Dr. Prichard's \"Researches into the Physical\nHistory of Mankind,\" vol. i. p. 366.\n\nAmong the lower animals, albinism appears to occur most frequently in\nthe race of tame rabbits; they are known by their white fur and red\neyes; breeds of these may be propagated; the same observation applies\nto white mice.\n\nHuman albinos, at least, and probably albinos in the animal grade, are\naffected by a certain degree, more or less decided, of day-blindness.\nThe characters of the albino result from a deficiency in the colouring\nprinciple, common to the skin, hair, and eyes. The eyes, for example,\nare entirely destitute of the dark pigment; in fact, the pink, or red\ncolour, so observable, depends on the fine vessels which are very\nnumerous in the composition of the iris, and on the still greater\nnumber of minute arterial ramifications which almost entirely form the\nchoroid membrane, and which, under this condition, are seen through\nthe pupil. To Albinos the state of the eyes is their greatest source\nof inconvenience. The absence of the black pigment, which has the\nimportant office of absorbing superfluous portions of light, renders\nthe eye preternaturally sensible of this stimulus. Strong lights affect\nthe organ painfully; even the glare of open day produces a partial\nblindness, and the admission of light is intolerable. These evils\nare balanced in some measure by superior power of vision in dusk, or\nimperfect darkness.[31]\n\n[31] On this subject see Buffon, Supplement, tom. iv. p.\n559; Pallas in his \"_Nov\u00e6 Species Quadrupedum_,\" pp. 10,\n11, _n._, and also Blumenbach, etc.\n\nLet us now turn to night-blindness. \"Nocturnal blindness,\" says\nScarpa, \"is properly nothing but a kind of imperfect _periodical\namaurosis_, most commonly sympathetic with the stomach. Its paroxysms\ncome on towards the evening, and disappear in the morning. The disease\nis endemic in some countries, and epidemic, at certain seasons of\nthe year, in others. At sunset, objects appear to persons affected\nwith the complaint, as if covered with an ash-coloured veil, which\ngradually changes into a dense cloud, intervening between the eyes and\nsurrounding objects. Persons thus affected have the pupil, both in the\nday and night-time, more dilated and less movable than it usually is\nin healthy eyes. The majority of them, however, have the pupil more or\nless movable in the day-time, and always expanded and motionless at\nnight. When brought into a room faintly lighted by a candle, where all\nthe bystanders can see tolerably well, they cannot discern objects at\nall, or at most in a very feeble manner, or they only find themselves\nable to distinguish light from darkness, and by moonlight their sight\nis still worse. At daybreak they recover their sight, which continues\nperfect all the rest of the day till sunset.\"[32]\n\n[32] Cap. xix. p. 322. Ed. 8vo.\n\nMr. Bamfield observes that the abolition of eyesight by night has\noccurred in all ages, and is a common disease of seamen in the East and\nWest Indies, the Mediterranean, and in all hot and tropical countries\nand latitudes, and that it affects more or less the natives likewise of\nthose regions of the globe. It also occurs frequently among soldiers\nin the East and West Indies, but, according to the information he\nhas received, it is by no means prevalent amongst sailors employed\non shipboard. It is not an uncommon complaint among the Lascars\nemployed in the East India Company's ships, trading between India and\nEurope. Celsus has remarked that females in due health are exempt from\nthis strange affection of the orbs of vision.[33] It may further be\nobserved, that the inhabitants of northerly latitudes are less subject\nto night-blindness than are the natives of tropical countries in\ntheirs; but that when the natives of cold climates visit the tropics,\nthey are peculiarly susceptible to this morbid condition of the eye.\n\n[33] Lib. vi. cap. vi.\n\nBut we must now pass from the eye to the ear. Deafness from infancy,\nthat is, total deafness, involves the loss of speech, or of the\nutterance of a definite language. The deaf do, indeed, utter wild\ncries, and, as if impelled by instinct, scream with rage, howl with\npain or fear, and mutter when pleased; but they hear not the sounds\nwhich they themselves utter, and which are often harsh, and even\nterrible.\n\nThe grand object for which the sense of hearing was given to man was\nfor understanding, acquiring, and using language, or speech, for the\nenunciation of which the lips, the teeth, the tongue, the palate, in\nfact, the whole organization of the mouth and lower part of the face,\nis expressly modified, as is also the conformation of the larynx;\nbut, be it observed, that without mind man could never have been a\nspeaking animal. Here, then, we see a design often overlooked by those\nwho study the economy of man. The ox hears, but it could not talk or\nutter language--that is, sounds modified in accent, in termination,\nin length--even if it would, for the organization of the vocal organs\nwould prevent the required intonations; but as the lower animals are\nnot destined to think, to argue, to admonish, to persuade--in short,\nas they are not destined for immortality--in them the faculty of\nspeech would be out of harmony with their real condition and destiny.\nLanguage is a mental as well as corporeal exercise, for we have to\nlearn what each sound uttered means, till at length it becomes natural\nto us, if we may use a popular expression. We have already alluded to\nthe pleasure which the mind derives from music. Now, there are a few\nobservations regarding deafness, or the deprivation of hearing, which\ncannot be out of place. Total deafness from various causes may take\nplace in a person of mature years, or after he has advanced in life\nto years of adolescence; in such cases language will be retained, but\nthe voice will be under no control, no modulation--one sentence may be\nshouted, another spoken in a whisper.\n\nWe may adduce a case in point: an officer (a nobleman) in the battle\nof Waterloo had his auditory nerve destroyed by the concussion of the\nair from the bursting of a shell, or from the report of a cannon. He\nbecame totally deaf, and consequently lost all control over his voice,\nwhich became discordant, and difficult to be understood even by those\nwho were his intimate associates. A similar instance is mentioned by\nan American writer, in which entire deafness, taking place at the age\nof eighteen, so affected the articulation, that the individual was\nno longer intelligible, even to his nearest friends. But, besides\ntotal loss of hearing, whether congenital, (that is, from birth,) or\noccurring at any future period, auditory incapacity manifests itself\nin various degrees, and under singular modifications. For example, a\nfriend of the writer, who is extremely musical, and plays brilliantly\non the piano, is so deaf that she scarcely understands a word of the\nconversation of persons around her; yet let a discordant note be\nstruck, and she feelingly appreciates it. Another lady, with whom the\nwriter is acquainted, cannot hear the shrill high-toned squeak of the\nshrew-mouse; and the writer knows some who cannot hear the cries of\nother shrill-toned animals, as the bat, or mouse, while to deeper, not\nlouder notes, their ears are perfectly awake.\n\n\"Dr. Wollaston constructed a small organ, whose notes began where the\nnotes of ordinary instruments end; the notes of his organ increased\nin sharpness till they became inaudible, though he was certain that\nit continued to give sound, from feeling the vibrations equally with\nthe lower notes. He thus found that some people could hear seven or\neight notes higher than others, and that children could generally hear\ntwo or three notes higher than grown-up people. In some persons, the\naccuracy of the ear is merely impaired in distinguishing faint sounds,\nand sounds somewhat similar; instances of this kind are particularly\nevident in infants, whose first attempts at speech are a very remote\nsimilarity to the sounds they hear, and become more perfect as their\near is educated, and in some cases remain imperfect through life, in\nconsequence of defect in the organs of hearing. All imperfections of\nspeech do not arise from imperfect hearing; an indistinct articulation\nmay result from various other causes; from carelessness, from defective\norgans of speech, or from an imperfect formation of those organs; from\nirregular respiration, producing hesitation, and in some instances\nproceeding from nervousness.\"[34]\n\n[34] See Dr. Arnott's \"Elements of Physics,\" 1827.\n\nThe writer is acquainted with a lady, whose organs of hearing are\nin full activity, but she cannot distinguish one tune from another;\nher ear appreciates _piano_, _forte_, or _fortissime_, but neither\nmodulation nor rhythm. The defect here must be in the mind, (a\nphrenologist would say that the organ of music in the brain was\nundeveloped,) yet this lady is sensible, pious, and strenuous in her\nexertions for the extension of the knowledge of Christ.\n\nTo revert, however, to the deaf and dumb (or deaf-mute) not deprived\nof eyesight, we may observe, that these persons, formerly neglected\nand deemed incapable of instruction, are not now excluded from the\nschool of knowledge and of religion. Men have at length confessed\nthat they possess rational souls--that they are capable of receiving\ninformation--and that the mind may be made the recipient of a certain\namount of knowledge, varying of course according to the natural powers\nof the intellect. Not that the amount of knowledge acquired by such\npersons can ever, _c\u00e6teris paribus_, equal that which may be acquired\nby those who labour under no defect; nevertheless, the inferiority is\nonly one of degree, and is easily accounted for. An able writer makes\nthe following pertinent remarks: \"From the advantages which instruction\nhas afforded to a certain proportion of the deaf and dumb for the last\nhalf century, a tolerably correct estimate may be formed of their\ncapabilities for improvement. The deaf-mute, living in society, but\nwithout instruction, must be regarded as one of the most solitary and\nmelancholy of beings. He is shut out from all but the most imperfect\nintercourse with his species, and the very intellect, by the possession\nof which he is raised above the lower creation, serves only to\nheighten his calamity, and render the sense of his deprivation more\nacute. His perceptions of external objects are indeed accurate, but\nsuperficial, and confined to a very small sphere.\n\n\"Of the various arts by which the necessaries and conveniences of life\nare produced, he can have no knowledge beyond that which is included\nin the range of his own vision. Animal desires he feels, and he is\nled by the conventional usages of society to the performance of moral\nduties, and the avoidance of open and flagrant crime. Thus he becomes\nexperienced, as other human beings are, in what is right or wrong.\nHe sees that virtuous actions have a certain amount of reward in the\nopinions of good men, for he learns to discriminate between those whose\nactions are proper, and those who do wrong; and, again, he sees that in\nmany cases vice meets with disapprobation and punishment among mankind.\nHow this kind of experience shall affect his own conduct, must depend\nnot only on the circumstances in which he is placed, as to example, and\nthe moral influence of those with whom he has to associate, but also on\nhis own natural tendencies. The performance of moral duties implies the\nexercise of intellectual faculties, and from his birth the deaf-mute\nmakes use of his reasoning powers. He is subject to changes of purpose,\nto changes of feeling, the pleasures and the infirmities common to his\nspecies. He is sensible of kindness; he gives proof of affection.\nThat such is the uneducated state of the deaf and dumb might be proved\nby the observations of their parents, friends, and instructors,\nin hundreds of instances. That such must necessarily be the case,\nsupposing them not to be idiots, it would be easy to show. We affirm,\nin contradiction to those who contend that deaf-mutes are naturally\nmore debased than other men in intellect and in morals, that there is\nnot an individual deaf-mute, now under instruction, improving, and\nthereby evincing rational faculties, who, previous to his instruction,\nhowever disadvantageous the circumstances which attended his earlier\nyears, did not evince moral sentiments and intellectual operations.\nWe have traced the history of many of this class, in different ranks\nof society, down to the period when the deprivation under which they\nhave laboured was first ascertained; and we have invariably found that\nmixture of good and evil in their actions and tendencies, which is\nseen amongst other children. We have also had sufficient proofs of the\nexercise of intellect even while they were in a state of childhood. The\nparents of deaf and dumb children can sufficiently attest the truth of\nthese observations.\"\n\nThe writer can attest them: he can adduce facts within his own\nknowledge, proving the correctness of the views entertained by the\nauthor just quoted; reasons, however, sufficiently obvious prevent him\nexpatiating on this part of the subject, and, indeed, have influenced\nhim in adopting the words of another, whose means of observation have\nbeen very extensive. We cannot here enter into the modes of instruction\nemployed in order to illuminate the minds of the deaf-mutes; all we\nneed say is, that it is by a system of apt signs, or of hieroglyphics,\nat least in the commencement; but minds of capacity soon advance still\nfurther; reading and writing are acquired--nay, even the power of\narticulate speech. But we must pass from this part of our subject, on\nwhich indeed much might be said.\n\nThe senses of smell and taste require a passing notice. We conjoin\nthese senses together, because the latter depends much for its\ndiscrimination on the functional perfection of the former; in fact,\nmuch of that which in the enjoyment of food is commonly attributed\nto the sense of taste, depends on the odour carried from the mouth\nto the nose. If, for example, we masticate any spice, or aromatic\nsubstance, as cinnamon, while at the same time the nostrils are\nstrongly compressed, and breathing through those channels obstructed,\nwe perceive no definite flavour from the spice, although the essential\noil expressed may sting the tongue and palate. Stoppage of the\nnasal passages, from catarrh, influenza, or other affections, and\npreternatural dryness or thickening of the schneiderian membrane,\nimpair or destroy both the sense of smell and taste. We may here\nobserve, that irritation of the schneiderian membrane by ammonia, by\nsnuff, and other things of the like nature, has nothing to do with the\nsense of smell residing in the nerves of that membrane: smell is the\nappreciation of odours; any delicate membrane may be irritated, as,\nfor example, the conjunctiva of the eye. With irritants, scents may\nbe combined; in such admixtures for the stimulation of the olfactory\nnerves many persons eagerly indulge, and under certain circumstances\nthey are medicinally useful; but it is the perception of scent or\nodour, irrespective of irritation, which is the proper function of the\nolfactory nerves.\n\nWith respect to taste, this sense resides in a branch of the fifth\ncerebral nerve, called, from its function, gustatory. For the sensation\nof taste, moisture must be present; an utterly insoluble body, as\ncrystal, is tasteless; we reduce to a pulp, by means of the teeth and\nthe saliva, the food which we eat, excepting, indeed, such articles as\ncome under the denomination of drink, or, in other words, viands in a\nfluid state, such as wine, ale, coffee, etc. Perfectly pure water is\ntasteless.\n\nThe contact of two metals in the mouth, producing a galvanic discharge,\nexcites a sensation or flavour which cannot be well described; but the\nmoisture of the saliva is requisite for the effect. It is said, that\nthe superior flavour of porter drunk out of a pewter vessel results\nfrom a slight galvanic action going on. Mr. Mayo says, \"various\nsubstances, after exciting the sense of touch on the fauces, and that\nof taste on the tongue, are capable of producing a third impression,\nwhich is popularly referred to the palate, but which is really felt\nupon the sentient membrane of the nostrils.\" In the case of metals\ntaken into the mouth, this mode of the reception of flavour would\nappear to take place.\n\nLoss of taste, like that of smell, may arise from various causes; when\nthe mouth is parched up by fever or intense thirst, the sense of taste\nis greatly impaired, or even altogether suspended; but this condition\nmay be regarded as temporary. A few instances have come under our\nown observation, in which, though the senses of smell and taste were\nnot obliterated, they were extremely obtuse, insomuch that the most\nnauseous medicines or offensive odours created no feeling of repugnance\nor disgust, and the most delicate viands, or the fragrance of sweetest\nflowers, no pleasurable sensation. In idiots, this loss of taste and\nsmell is far from being uncommon; but it is not to such that we here\nallude, nor is it to those who have suffered from repeated partial\nstrokes of paralysis or apoplexy, but to persons of sane mind and\nsound health. In such cases, the deficiency is either in the sensitive\nand conducting power of the nerves, or in some a loss of tone in the\nportion of the brain to which they immediately lead--at all events, a\nbarrier is interposed between organic structure and the mind.\n\nAs far as the operations of intellect are concerned, the loss of smell\nor of taste is of secondary consideration; these senses administer to\nour animal enjoyments rather than to the spiritual part of our being;\nnevertheless, mind and body are so united that the breath of early\nflowers, the incense of the fields, the balmy breeze, the taste of\nwholesome food, or of the refreshing draught, call forth the feelings\nof the mind, awaken gratitude, and lead us to offer up our thanks to\nHim who is the Giver of every good.\n\nWith respect to the sense of touch, we have few additional observations\nto make; this sense is trained to its highest perfection in those who\nare born blind, and who from early childhood have acquired the habit\nof supplying by its exercise their visual deficiency, as far as one\nsense can compensate for the loss of another. In the educated blind,\nthe faculty of distinguishing minute differences in impression, and\nof receiving from a given surface of sentient integument the largest\nnumber of separate sensations of contact, appears most remarkably\ndeveloped; in the blind, too, the exploring movements of touch are\nperformed with the most skill and delicacy. To so high a pitch, indeed,\nis the sense of touch elevated, that many have been led to believe that\nthe blind are even capable of appreciating colour; it may be, we admit,\nthat they are able to detect by touch certain differences of texture,\nwhich depend on the chemical processes of dyeing, or on certain modes\nof preparation connected with the impartation of colour to the surface\nof objects, and thus discriminating or analyzing, may be taught to\nassociate the name of blue with one sensation, of red with another,\nand so on--more than this is impossible.\n\nObtuseness of feeling, or of tact, arises from various causes; the\nhorny hand of the labourer is less discriminative than that of the\nman who is not called to toil in the field, or work at the anvil. As\nregards feeling, independent of the pure sense of touch, there is much\ndifference even among individuals, according to the general nervous\nsusceptibility of the frame. Among the North American Indians this\nsusceptibility is less than among Europeans, as may be concluded from\nthe horrid details given by Mr. Catlin, and others, who have witnessed\nthe revolting practices of the red men of the western world.\n\nLoss of feeling, or of tact, in one or more limbs, is the result of\nparalysis, and other morbid conditions of the system, to which our\nfrail tenement is subject. The same observations apply to the muscular\nsense, which sense is moreover deranged, or suspended, during a fit\nof intoxication, (_Proh pudor!_) or when placed on some dizzy height,\none, unaccustomed to such a situation, is agitated by extreme terror.\nThe sailor in the rigging of the topmast, the cragsman of the Hebrides,\nthe hunter of the chamois, have learned to surmount such a sense of\nfear, and are secure in their place of peril. The loss of sensibility,\nand the loss of the muscular sense, can never pervade the whole frame,\ntill that hour arrives when the soul is about to quit its mortal abode,\nand enter the regions of another world. To this condition all are\ndestined--the sentence of death is gone forth! Oh that, while living,\nwhile in the enjoyment of our senses, and of the energies of our body,\nwe may \"lay hold upon eternal life,\" and live as \"dying daily!\" Let us\naim at being able to appropriate to ourselves the expression of the\npsalmist, \"My flesh and my heart faileth: but God is the strength of my\nheart, and my portion for ever.\"[35] No one can say this in verity, who\nis not established on the \"Rock of Ages.\"\n\n[35] Psa. lxxiii. 26.\n\nThe Almighty has not designed that man, even in this his probationary\nstate, should pass through his pilgrimage without experiencing pure\npleasures and delights. It is to these that the senses administer,\neach in its appointed way. The sublimity and the beauty of natural\nscenery--the grandeur of mountains, forests, and seas--the glory of\nthe sun, moon, and starry expanse above--the works of art, towers, and\ntemples--all these, and more, received into the mind through vision,\nproduce the most delightful emotions. The flowers that strew our\npathway, the insects glittering in the sun, the waving cornfields, the\ngrazing cattle, the rustic cottage of the hardy labourer--all combine\nto fill the soul with pleasure and thankfulness. Can we listen to the\nroar of waters, to the deep murmur of the wind rushing through the\nforest, to the song of birds, or the notes of sweet melody, and feel no\npleasure--no spirit of praise and gratitude? Is not food sweet to the\nhealthy appetite? Do we not rejoice in our strength, in the use of our\nlimbs, and in our manual address and precision? Are not the perfumes of\nflowers, the scent of the bean-field, of the bower of honey-suckle, of\nthe new-mown hay, delicious? Is not the earth full of riches? Has not\nthe Creator adapted it to our pleasures, as well as our necessities,\nand endowed us with every sense requisite for enjoyment? How delightful\nto the Christian--how doubly enjoyed by him is nature in all her\nphases, in all her manifestations, in all her variety! To him nothing\nis uninteresting, from the mightiest creature to the animalcule,\nfrom the cedar to the humble weed; and reflecting that knowledge\nstores his mind, and pleasure gladdens, refreshes, and animates him,\nthrough each respective medium; and delighting in life, and life's\nenjoyments, he praises God for every bodily and mental endowment,\nand for all the glorious works which his hands have created--works\nwhich lead him to muse upon that inscrutable wisdom, power, love, and\nconsideration, which the Almighty has displayed in fitting the earth\nfor him as his temporary abode--glorious in its mountains, its plains,\nits seas, and rivers--glorious in the light of day and the darkness\nof night--glorious in the air and the clouds, in the lightning and\nthe rainbow; but yet an abode to be exchanged by the believer for one\ninfinitely more glorious, in which sin and pain are unknown, and from\nwhich mortality is banished for ever.\n\n\n\n\n     Transcriber's Notes:\n\n     Page 65: Contrary to the other sections, section 8. of CHAPTER I.\n     has no header in the original.\n\n     Footnotes have been moved to directly under the text they refer to.\n\n     Changes made to the text:\n\n     Page 19 (table): \"Heats\" in the right column changed to \"Heat\"\n\n     Page 67/68: Added a \".\" at the end of the footnote\n\n     Page 153: The original read \"CHAPTER V.\" as heading of the last\n     chapter, this has been changed to \"CHAPTER IV.\" as there are only\n     four chapters.\n\n     Page 178: Quotes removed (originally: in others.\" At sunset,)\n\n     Page 179: \"effects\" changed to \"affects\" (it affects more or less)\n\n     Page 184: Quotes added (\"Of the various arts)","title":"The Senses and the Mind","tradition":"philosophy-ethics","translated_text":null,"word_count":47669}