Rayleigh Quenching of Active Nitrogen

Abstract

ARISING out of work¹ on the disappearance of the nitrogen afterglow by heating the activated gas at various pressures, it may be of interest to record results which indicate limits for the production of a like phenomenon observed by Lord Rayleigh², namely, the quenching of the afterglow due to cooling by liquid air. With a condensed discharge in a Crookes' tube connected in series with a long glass spiral S, and a small bulb containing powdered iodine, the activated gas excited the characteristic iodine luminescence even when the afterglow in the observation spiral S was feeble; both disappeared when S was cooled by liquid air, in agreement with Rayleigh's observation². That this phenomenon is, however, restricted to low pressures is shown by the fact that when the gas pressure was increased progressively from 0·1 mm. the Rayleigh quenching in S tended to be less marked; was uncertain near 30 mm. and not observed above 40 mm.