Mathew Carey Lea

Mathew Carey Lea Mathew (or Matthew) Carey Lea (published as M. Carey Lea; August 18, 1823 – March 15, 1897) was an American chemist and pioneer of the chemistry of photography. His 1868 book A Manual of Photography became a standard reference. Lea was elected in 1892 to the U.S. National Academy of Sciences. Quotes At no time has the subject of the influences of chemical agents on plants received so much intelligent attention as at present, and the labors of Jean-Baptiste Boussingault Boussingault, Wilhelm Knop Knop, Friedrich Stohmann Stohmann, Georges Ville Ville, Julius von Sachs Sachs, and many others, are daily adding to our stock of knowledge and developing new and interesting facts. The studies of these chemists have, however, been directed almost entirely to the effects of the absence or presence in greater or less proportion in the soil of those Base (chemistry) bases and acids which are there commonly found. Article XXXIV.—On the Influence of Ozone and some other Chemical Agents on Germination and Vegetation American Journal of Science 1864 2 111 573–576 (quote from p. 573) Much difference of opinion has long existed in respect to the explanation of certain Science of photography#Chemical processes phenomena of photographic action. In the vast majority of cases the action of light is a reducing one. Salt (chemistry) Salts of iron, of uranium, and of other metals are reduced from a higher to a lower stage of oxydation, and the same is the case with the combinations of certain metallic acids, such as bichromates and tungstates. These phenomena present no difficulty. It is only when we come to the silver haloids that obscurity commences. 1866 On the Nature of the Action of Light upon Iodid of Silver American Journal of Science 2 125 198–205 (quote from p. 198) Quotes about Matthew Carey Lea In 1896, shortly after the remarkable discovery of the Röntgen rays, Carey Lea made a series of very careful experiments to ascertain if these rays were detectable in sunlight. ...By far the most valuable as well as the most extended investigations of Carey Lea, however, were those which related to the Science of photography#Chemical processes chemistry of photography in which at the time of his death he was the acknowledged authority. His researches were directed chiefly to the chemical and physical properties of the silver haloid Salt (chemistry) salts, not only alone, but also in combination with each other and with various coloring matters, especially with reference to the action of light upon them under all these different conditions. George Frederick Barker, Biographical Memoir of Matthew Carey Lea 1823–1897, read before the U.S. National Academy of Sciences, April 21, 1903 Biographical Memoirs of the National Academy of Sciences, Vol. 5 1905 155–208 https://www.nasonline.org/wp-content/uploads/2024/06/lea-matthew-c.pdf (quote from pp. 173–174)| External links Category:1823 births Category:1897 deaths Category:Chemists from the United States Category:Lawyers from the United States Category:Members of the United States National Academy of Sciences Category:People from Philadelphia Category:Photographers from the United States Category:Science authors from the United States