A chemically active modification of nitrogen, produced by the electric discharge.—III

Abstract

In the first paper (2) it was mentioned that a stream of glowing nitrogen led through a tube cooled in liquid air glowed out with increased brilliancy, and then became extinguished. There is some ambiguity in the interpretation of this experiment, since the density of the gas is locally increased by cooling; and increased density may (and does) make the nitrogen expend its glowing power more quickly. A hermetically sealed bulb containing rarefied nitrogen was excited by the electrodeless discharge. Allowed to expend itself at room temperature, the glow in this bulb was conspicuous for more than a minute. But if the bulb was immersed completely in liquid air immediately after excitation, and after 15 seconds withdrawn and examined, it was found to be quite dark. The glow was very brilliant as seen under the surface of the liquid air. This experiment proves that the glow-transformation really occurs more quickly the lower the temperature, apart from changes of density.