But we are constrained to acknowledge that among our medical predecessors, these incentives were scarcely ever sufficiently powerful to induce them to leave us circumstantial and scientific accounts of contemporary epidemics, which, nevertheless, have, even in historical times, afflicted, in almost numberless visitations, the whole human race. Still less did it occur to them to take a more exalted stand, whence they could comprehend at one view, these stupendous phenomena of organic collective life, wherein the whole spirit of humanity powerfully and wonderfully moves, and thus regard them as one whole, in which higher laws of nature, uniting together the utmost diversity of individual parts, might be anticipated or perceived. Here a wide, and almost unfathomable chasm occurs in the science of medicine, which, in this age of mature judgment and multifarious learning, cannot, as formerly, be overlooked. History alone can fill it up; she alone can give to the doctrine of diseases that importance without which its application is limited to occurrences of the moment; whereas the development of the phenomena of life, during extensive periods, is no less a problem of research for the philosopher, who makes the boundless science of nature his study, than the revolutions of the planet on which we move. In this region of inquiry the very stones have a language, and the inscriptions are yet legible which, before the creation of man, were engraved by organic life, in wondrous forms on eternal tablets. Exalted ideas of the monuments of primæval antiquity are here excited, and the forms of the antemundane ways and creations of nature are conjured up from the inmost bosom of the earth, in order to throw their bright beaming light upon the surface of the present.