Bulletin of the National Research Council

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Excerpt from Bulletin of the National Research Council: The Present Status of Visual Science If we go back to the Greek philosophers of the fifth century, -b. C}, who were apparently the original progenitors of modern science, we find them attempting to explain the phenomena of vision as due to a collision of two streams of particles, the one emitted by objects and the other by the eye, representing respectively the physical and the physiological components of the process. Certain of these early thinkers, however, such as Democritus and Empedocles, also enter tained theories of primary and mixed colors, thus entering the field of psychology. The notion of light, or the physical agent in seeing, as a stream of corpuscles emitted from objects was generally accepted by the Greek thinkers and reappears in Newton's corpuscular hypothesis, at the dawn of modern optical science. Aristotle, however, advocated the view that light was an activity of an omnipresent me dium which he called the pellucid, thus foreshadowing the ether-wave hypothesis of Huyghens. The ancients as a whole, however, were not satisfied with the conception of the organism as being purely passive in the act of seeing and, as exemplified in the optics of Euclid, returned constantly to the hypothesis of an emission of particles from the eye itself. A very few of the ancients, for example Diogenes of Appolonia, recognized the dependency of sight upon the integrity of the optic nerve, and regarded the latter as a channel by which visual impressions were conveyed to the brain. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.