The Optical Spectrum of Hafnium

Abstract

DURING the progress of the work of Coster and Hevesy on the concentration and isolation of the new element hafnium (atomic number 72), the discovery of which was announced in NATURE of January 20, p. 79, we have examined spectroscopically a large number of their preparations in order to establish the optical spectrum of hafnium, and at the same time to assist in the chemical work on its isolation. In all our exposures we have for the sake of comparison also photographed the spectrum of a specimen of very pure zirconium prepared by Coster and Hevesy from commercial zirconium by removing the hafnium content.