XVIII. Researches in spectrum-analysis in connexion with the spectrum of the sun.―No. II

Abstract

In my former communication under the above title I pointed out that the new method of spectroscopic research adopted by Dr. Frankland and myself had enabled me to establish:— (1) That when a metallic vapour is subjected to admixture with another gas or vapour, or to reduced pressure, its spectrum becomes simplified by the abstraction of the shortest lines and by the thinning of many lines. (2) That when metals are chemically combined with another element (I used chlorine) only the longest lines of the metal remain in the spectrum of the chloride— the number being large in the case of elements of low atomic weight, and small in the case of elements of high atomic weight and of twice the atom-fixing power of hydrogen.