Ultra-violet absorption of ice

Abstract

It was proposed to compare the absorption spectra of condensed substances with their absorption in the gaseous state, as little is known of the nature of the light absorption process in solids, and it was hoped to discover the effect upon the molecular terms of embedding the molecules in a crystal lattice. A vacuum spectrograph was used with fluorite prisms and lenses transparent down to a wave-length of 1400 A. Water was first employed as a test substance because the technique is simple. A a gas it has no discrete bands in this region—or to be more accurate, only very weak and diffuse ones, superimposed on a broad absorption continuum. However, the results proved of some interest—especially as the spectra of light and heavy ice could be compared in the same way as has been done by Franck and Wood for water vapour.