The Spectrum of Metargon

Abstract

THE letter which Messrs. Ramsay, Travers and Baly have addressed you on this subject calls for one or two remarks. The similarity between the carbon and metargon spectra does not only apply to the green band, but to the whole of the visible spectrum, and also, as my previous letter pointed out, to the ultra-violet band commonly ascribed to cyanogen. With the ordinary coil discharge I could see nothing but carbon bands, and it is contrary to all experience that two dissimilar bodies should give complicated spectra so much alike that a two-prism spectroscope can detect no difference between them. With the Leyden jar a strong continuous spectrum appeared, and, overlapping it, some of the lines of argon. The blue argon lines were absent, but my examination was not sufficiently detailed to allow me to say, that the visible lines were those commonly found in the “red spectrum.” Neither with nor without the jar did I see any line which could not be assigned either to carbon or to argon, but I should have liked to try a stronger jar and a more powerful coil. With the jar there seemed to me to be signs of decomposition of the gas, as, on removing it again, the carbon lines were weak at first and only gradually returned. The pressure in the tube was rather high; and if the tubes experimented upon by Prof. Ramsay and his coadjutors were all at the same pressure, I should not attach much weight to their observation that the carbon oxide spectrum did not make its appearance after introduction of oxygen, for that spectrum only shows well at lower pressures.