VII.—The Absorption of Light by Inorganic Salts. No. V.: Copper and the Alkali Metals

Abstract

The research described in this article was undertaken with the double purpose of testing new apparatus and of making a rapid survey of the absorption of light by salts of the first periodic group.The results described in the previous articles were obtained by three separate methods, viz. the thermopile in the infra-red, the spectrophotometer in the visible spectrum, and the photographic spectrophotometer in the ultra-violet. It would be a great simplification if the same apparatus could be used throughout the whole spectrum, and I therefore first of all devoted my attention to seeing if this were practicable.