The line spectrum of chlorine in the ultra-violet (Region λ 3354 — 2070 A.)

Abstract

The lack of success in the analysis of the Cl line spectrum may be partly due to the imcompleteness of experimental data. Paulson has discovered certain constant differences of wave-number, but in the absence of any recognition of series, these differences are at present of restricted significance. Observations with Cl discharge tubes present difficulties (to which Kayser and Hagenbach and Konen have drawn attention) caused by the chemical activity of Cl. The gas attacks not only the metal of the electrodes and the mercury in the pump, but also the tap-grease and the cement used for the attachment of a quartz window. Only glass discharge tubes have been used, and the quartz ultra-violet region thereby sacrificed, e. g ., the observations of Eder and Valenta end at λ 3276 A. Again, only comparatively high gas pressures have been employed; under these conditions the lines were broadened, and a continuous background was