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Show covered that when the purple becomes be-comes transparent a slightly yellow material Is split off from it. This material, a hitherto unknown chemical, chem-ical, was found to be closely related to carotene, which, in turn, is a close relative of vitamin A. Doctor Wald then actually witnessed wit-nessed the transformation of the new yellow substance into vitamin A. Literary Digest. Sees Kinship Between Vitamins and Vision The manner in which the eye works; particularly how it perceives what one knows as color, Is a very considerable mystery. The puzzle Is not very much clarified, but is possibly pos-sibly made more interesting, by the recent discovery that there Is a close relation between vitamin A and the rhodopsin of "visual purple" in the retina. It has long been known that visual purple, which plays an important part In the functioning of the retinal re-tinal rods, Is sensitive to light, bleaching to a colorless material when exposed to illumination. Watching this phenomenon, Dr. George Wald, at the Oceanographic Institute, Woods Hole, Mass., dis- |