Note 29 — Chapter IX · COMPOUNDS OF CARBON WITH OXYGEN AND NITROGEN

It is remarkable that, according to the investigations of Dixon, perfectly dry carbonic oxide does not explode with oxygen when a spark of low intensity is used, but an explosion takes place if there is the slightest admixture of moisture. L. Meyer, however, showed that sparks of an electric discharge of considerable intensity produce an explosion. N. N. Beketoff demonstrated that combustion proceeds and spreads slowly unless there be perfect dryness. I think that this may he explained by the fact that water with carbonic oxide gives carbonic anhydride and hydrogen, but hydrogen with oxygen gives hydrogen peroxide (Chapter VII.), which with carbonic oxide forms carbonic anhydride and water. The water, therefore, is renewed, and again serves the same purpose. But it may be that here it is necessary to acknowledge a simple contact influence. After Dixon had shown the influence of traces of moisture upon the reaction CO + O, many researches were made of a similar nature. The fullest investigation into the influence of moisture upon the course of many chemical reactions was made by Baker in 1894. He showed that with perfect dryness, many chemical transformations (for example, the formation of ozone from oxygen, the decomposition of AgO, KClO3 under the action of heat, &c.) proceeds in exactly the same manner as in the presence of moisture; but that in many cases traces of moisture have an evident influence. We may mention the following instances: (1) Dry SO3 does not act upon dry CaO or CuO; (2) perfectly dry sal-ammoniac does not give NH3 with dry CaO, but simply volatilises; (3) dry NO and O do not react; (4) perfectly dry NH3 and HCl do not combine; (5) perfectly dry sal-ammoniac does not dissociate at 350° (Chapter VII., Note 15 bis); and (6) perfectly dry chlorine does not act upon metals, &c.