The British Journal for the History of Science

Research Article

Spectroscopy and the Elements in the Late Nineteenth Century: The Work of Sir William Crookes

Robert K. DeKoskya1

a1 Department of History, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, U.S.A.

Two imposing related problems confronted the chemical spectroscopist of the late nineteenth century. First, he lacked a criterion for judging the validity of claims for elemental discoveries; indeed, he possessed no satisfactory operational definition of the chemical element. Secondly, he felt the need for correlating the spectra of the elements to a conception of their ultimate constitution.