A comparative study of the spectra, densities, and melting points of some groups of elements, and of the relation of properties to atomic mass

Abstract

This investigation was begun in the hope that it would lead to the discovery of some of the laws which determine the distribution of lines and bands in spectra: those laws, more especially, which govern the changes of oscillation frequency of corresponding lines in the spectra of some of the metals. A. Mitscherlieh appears to have been the first to make a comparative study of spectra. He compared the spectra of the haloid salts of the metals of the alkaline earths. He found that individual lines recur in the spectra of one and the same metal, which, according to the halogens, are more or less distant from one another. Fluorides form an exception. In the spectra of barium compounds the distances (on the scale of his spectroscope) between two prominent lines in the various spectra were to each other as the “atomic weights” of the compounds.