Spectroscopic observations on the active modification of nitrogen. —V

Abstract

The spectrum of the nitrogen afterglow, as ordinarily obtained, consists of three groups of bands, which we designated as the α, β , and γ groups. The α -group is in the visual region, and consists of a selection of the first positive bands of nitrogen. The β -group is chiefly in the ultra-violet, but extends into the violet. It can be observed in the discharge, but is much better developed in the afterglow. The γ -group is wholly in the ultra-violet, and identical with Deslandres’ third positive nitrogen group. I have not much to add to the results of the former paper as regards the measurement and classification of these various groups of bands. The circumstances under which they appear have, however, been reinvestigated, and the conclusions of the earlier paper modified in some important respects.