Excerpt from Proceedings of the American Academy of Arts and Sciences, Vol. 50: From May 1914, to May 1915 The relations Of the three fundamental color sensations of the Young Helmholtz theory, at least rest on a sound experimental basis and it is well understood that ordinary cases of color blindness imply an easily measurable deficit in one Of these sensations. 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.