The London, Edinburgh, and Dublin, Vol. 24 PDF Download

Author: David Brewster
Publisher:
ISBN: 9781330625217
Category : Science
Languages : en
Pages : 566

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Book Description
Excerpt from The London, Edinburgh, and Dublin, Vol. 24: Philosophical Magazine and Journal of Science; January June, 1844 I. On the Action of Yellow Light in producing the Green Colour, and Jndigo Light the Movements., of Plants. By D. P. Gardner, M.D., Corresponding Member of the Lyceum of Natural History, New York. 1. The object of this paper is to prove the existence of different properties in the rays of the spectrum, in their action on vegetables; and more especially to show that the rays which produce the green colour of plants are altogether dissimilar from those which influence their movements towards light; the colour being developed by the less re-frangible rays, and chiefly by the yellow; whereas the motion is influenced by indigo light. The discussion of the subject will be divided under three heads: - 1st. On the Production of Chlorophyl by yellow light. 2nd. On the Movements of Plants towards indigo light. 3rd. Some applications of these facts to vegetable physiology. Part I. On the Production of Chlorophyl by yellow light. 2. It is a fundamental fact in botany that light is necessary to the formation of chlorophyl. Von Humboldt adduced certain exceptions to this law, in the case of plants found in the mines of Freyberg, and with Senebier ascribed the green matter to the action of hydrogen gas. But the experiments of the latter have failed in the hands of DeCandolle, and a series instituted by myself, and conducted with great care, were equally unsuccessful. On the other hand, Humboldt succeeded in greening a plant of Lepidium sativum, raised in darkness, by the light of two lamps, and DeCandolle obtained the same result with six Argand lamps. 3. The investigation has been subsequently confined to the name of the ray which produces the chlorophyl. 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.