Note 12 — Chapter V · NITROGEN AND AIR

This property of nitrogen, which under normal conditions is inactive, leads to the idea that under the influence of an electric discharge gaseous nitrogen changes in its properties; if not permanently like oxygen (electrolysed oxygen or ozone does not react on nitrogen, according to Berthelot), it may be temporarily at the moment of the action of the discharge, just as some substances under the action of heat are permanently affected (that is, when once changed remain so—for instance, white phosphorus passes into red, &c.), whilst others are only temporarily altered (the dissociation of S6 into S2 or of sal-ammoniac into ammonia and hydrochloric acid). Such a proposition is favoured by the fact that nitrogen gives two kinds of spectra, with which we shall afterwards become acquainted. It may be that the molecules N2 then give less complex molecules, N containing one atom, or form a complex molecule N3, like oxygen in passing into ozone. Probably under a silent discharge the molecules of oxygen, O2, are partly decomposed and the individual atoms O combine with O2, forming ozone, O3.