On the Spectrum of Carbon

Abstract

IN addressing to you my former letter regarding Dr. Watts's experiments on the spectrum of carbon, it was not my intention to enter on any discussion concerning matters of opinion. The reference made in that letter to the difficulty of perfectly drying a gas so as to eliminate the ultra-violet spectrum of water had reference to gases at ordinary atmospheric pressure; and the expectation a gas will be dried “to all intents and purposes” by the use of a U-tube of phosphoric anhydride goes far to explain the origin of different experimental results. The cogent experimental evidence which Dr. Watts justly demands may, so far as the relations of carbon and nitrogen are concerned, be found in our complete papers on the spectrum of carbon compounds in the Proceedings of the Royal Society.