The spectrum of the lighter constituents of the air

Abstract

In 1900, Professors Liveing and Dewar published a paper on “The Lighter Constituents of Air,”* and gave a table of wave-lengths for nearly 300 lines. Some of these were shown to be produced by hydrogen, helium, and neon, but the greater number were of unknown origin. A few years later the spectrum of pure neon was published by Baly,† and it was shown that many of Liveing and Dewar’s lines were due to that gas, but at the same time 162 lines remained which, in the opinion of that observer, did not belong to neon.