THERE are few tasks at once so instructive and so fascinating as the tracing of the development of the human mind as manifested in the evolution of scientific and philosophical theories. And this is, perhaps, especially true when, as in the case of medicine, this evolution has followed paths so tortuous, intersected by so many fantastic byways, that one is not infrequently doubtful as to the true road. The history of medicine is at once the history of human wisdom and the history of human…