On the band-spectra of silicon oxide and chloride, and chlorides of carbon, boron, and aluminium

Abstract

Though the chlorides of the lighter elements in Group IV, and to a less extent of those in Group III, have frequently been employed in investigations of spectra of the elements and certain of their compounds, little appears to have been recorded of the spectra of the chlorides themselves, which are described in the following pages. Examples of these investigations are:— ( a ) Professor Fowler's work on the Antarian band-spectrum of titanium oxide —in the course of which, observations of the titanium-tetrachloride tube-discharge showed “that not only is the spectrum of the chloride free from the Antarian flutings, but that it is characterised by a perfectly different group of flutings in the blue, which does not occur in the stellar spectra. This ‘chloride group’ as it may be conveniently called for purposes of reference, is a somewhat complicated cluster of flutings, fading towards the violet, having three principal heads at wave-lengths 4199·5, 4192·7 and 4188·0 (R. A.), of which the middle one is the brightest.”