Physics and Chemistry: Preliminary Report on the Masses of ¹²C and ¹⁴N

Abstract

WITH a newly constructed mass-spectrograph of Bainbridge and Jordan type¹, we measured the mass differences of ¹²CH₄–¹⁶O and of ¹²CH₂–¹⁴N. These ions were produced by electric discharge through a mixture of methane, carbon dioxide and air in a cylindrical discharge tube of the usual type. In addition to these doublets, lines of NH₃, NH₂, CH₃, CH, C were also simultaneously obtained on the same plate. Photographic plates employed in this work were prepared from the commercial process plates by Schumannization, 10–20 seconds being sufficient for photographing spectral lines on these plates.