A reversible discharge tube

Abstract

R. W. Wood has described an interesting discharge tube which could be made to exhibit either the spectrum of atomic hydrogen or molecular oxygen at will on excitation by a high-frequency discharge. In the course of investigations on the spectra of gases excited by high-frequency discharge, we have prepared a discharge tube which has an analogous behaviour and can be made to show either the air spectrum or hydrogen spectrum as desired. The fundamental difference between the two tubes, however, is that under the discharge hydrogen is suppressed by oxygen in Wood's tube, whereas here, hydrogen suppresses air.