On the action exerted by certain metals and other substances on a photographic plate

Abstract

Abstract Having some years ago prepared for the purpose of spectroscopic examination several uranium compounds, it was of interest to make further use of them by repeating some of the very important experiments which Becquerel has made with these compounds. He has shown that if the metal or some of its salts be placed on a photographic plate in perfect darkness, and allowed to remain there for some days, the plate becomes acted on, the action being rendered evident by the ordinary photographic process of development. This action is readily produced, and belongs apparently to all the salts of this metal, and, as Becquerel has shown, to uranous as well as uranic salts.