Scientific memoirs : being experimental contributions to a knowledge of radiant energy / by John William Draper.

  • John William Draper
Date:
1878
Catalogue details

Licence: Public Domain Mark

Credit: Scientific memoirs : being experimental contributions to a knowledge of radiant energy / by John William Draper. Source: Wellcome Collection.

    408/488 (page 404)
    MEMOIR XXIX. ox THE DISTEIBUTION OF CHEMICAL FORCE IN THE SPECTRUM. From the American Journal of Science and Arts for December, 1872, and Januaiy, 1873; Philosophical Magazine, December, 1872. Contents:—The curves of the calorific, luminous, and chemical S2)ec- tra. — Their errors,—Inappropriateness of the term actinic rays.— There is no localization of chemical effects.—Every radiation can pro- duce some specific effect.— Case of the silver compounds.—Bitumens and resins.— Carbonic acid.— Colors of flowers.—Laiv of Qrotthus— Chlorine and hydrogen.—Bending of stems of pilants.—Absorption es- sential to chemical action.—Decomposition of silver iodide.— Union of chlorine and hydrogen.—Angstrom''s laiv. — General conclusions.— Chemical force exists in every portion of the spectrum.—Each radia' tion exercises chemical influences pi-oper to itself. With scarcely an exception, the most recent works on the chemical action of radiations and sj)ectrum analysis describe a tripartite arrangement of the spectrum, illus- trated by an engraving of three curves, exhibiting the supposed relations of the calorific, the luminous, and the chemical spectra. This view, which by a mass of evi- dence may be shown to be erroneous, is exerting a very prejudicial effect on the progress of actino-chemistry. I propose now to present certain facts which may aid in correcting this error. For this purpose it is necessary to show that chemical effects—decompositions and com- binations—may take place in any ]3art of the spectrum. The points to be established may be thus distinctly stated: 1st. That so far from chemical influences being re-