An Attempted Photochemical “Resolution” of Silver

Abstract

THE recent correspondence between Prof. Schuster and Mr. Soddy in these columns suggests the placing upon record of a bold but unsuccessful attempt to split up the element silver which I made some years ago with one of my students. In these days, when tentative speculations are figuring so largely in the scientific world for positive knowledge, it may be necessary to point out that the research was prompted by no theoretical views concerning the compound nature of silver. But while there was no special a priori reason for suspecting the elemental character of that metal it was well known as a fact that its chloride, &c., on exposure to light only underwent a limited decomposition”i.e. that the photo-reduction ceased when a certain minute proportion of “photosalt” had been formed. The consideration of this property of the silver halides suggested the interpretation (purely hypothetical!) that the “element” contained a constituent (say, α-silver) of which the chloride was sensitive to light, and another (say, β-silver) less sensitive or insensitive to light. From this it followed that if, after exposure and complete saturation with “photo-salt,” the unchanged chloride could be separated from the photo-reduction product, the latter, on reconversion into chloride, should furnish a salt very highly sensitive as compared with the main portion of unchanged chloride.