Open AccessA critical search for a heavier constituent of the atmosphere by means of the mass-spectrograph
Author(s) -
F. W. Aston
Publication year - 1923
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1923.0070
Subject(s) - xenon , krypton , atmosphere (unit) , spectrograph , volume (thermodynamics) , chemistry , physics , nuclear physics , meteorology , thermodynamics , spectral line , astronomy
Ever since the discovery of the gases of the helium group in the atmosphere, speculation on the possible existence of another, of higher atomic weight than xenon, has been of great interest. In the experiments which led to the discovery of krypton and xenon in 1908 Ramsay and Travers used 750 c. c. of liquid air and obtained about 3 c. c. of xenon, which showed no indication of the presence of a heavier element. Later Ramsay showed that xenon was only present to the extent of 1 part in 1·7 x 108 parts of air by volume so that, with the means of analysis then available, a search for a still rarer heavier constituent clearly involved the handling of very large quantities of liquid air. This search was undertaken by Moore, who published an admirable account of his work in this Journal. After overcoming the very formidable difficulties of dealing with the liquid residues from 100 tons of liquid air Moore obtained 220 c. c. of xenon which was then fractionated down to 1/3 c. c. The spectrum given by the last fraction was indistinguishable from that of ordinary xenon from which he concluded that no heavier constituent was present to the extent of 1 part in 2·5 x 109 parts of air by volume. A theoretical discussion of this result is given by Ramsay.