OXYGENATED COMPOUNDS OF NITROGEN. 



tained N = 44, = 37, N0 2 = 13 for 100 volumes of the 

 original gas. 



On account of the duration of the reaction, and of the 

 antagonistic influence tending to the formation of nitric peroxide, 

 in a mixture of pure nitrogen and oxygen traversed by the 

 spark, the above system must be regarded as nearly in a state 

 of equilibrium. 



But to return to the nitric oxide. On the whole this compound 

 is less stable under ordinary conditions than the monoxide, 

 since it is capable of producing it by decomposition under the 

 influence of heat or the spark. Here an apparent contradiction 

 between the known properties of the two gases manifests itself. 

 Why do carbon, sulphur, phosphorus, when once ignited, 

 continue to burn more easily in the monoxide than in the 

 nitric oxide, a circumstance which has caused until now a 

 greater stability to be attributed to the latter gas ? The 

 explanation is the following (see pp. 62 and 63) : on the one 

 hand, nitric oxide does not contain more oxygen at equal 

 volumes than the monoxide, and, on the other hand, this 

 oxygen only becomes available in totality for combustion at a 

 much higher temperature, the nitric oxide being at first changed 

 to a great extent into nitric peroxide, a body really more stable 

 than nitrogen monoxide. The combustive energy of the nitric 

 oxide, at the temperature of incipient red heat, must therefore 

 be less than that of the monoxide, which is immediately resolved 

 into nitrogen and free oxygen. 



We have explained in the same way the impossibility of 

 exploding a mixture of nitric oxide and hydrogen, or carbonic 

 oxide. The combustion produced at the point of contact 

 with the incandescent body, or on the path of the spark, does 

 not raise the temperature to the degree requisite for the de- 

 composition of nitric peroxide, whilst explosive mixtures 

 liberating far more heat, as is the case with cyanogen and 

 ethylene, explode with extreme violence. 



The want of stability of nitric oxide is equally manifested in 

 a number of slow reactions, carried out with the pure gas at the 

 ordinary temperature, whether it be resolved into nitrite and 

 monoxide under the influence of potash (Gay-Lussac) 



4NO + K 2 dilute + water = 2KN0 2 dissolved + N 2 

 liberates + 39'2 Cal., 



or whether it gradually oxidise various mineral bodies in the 

 cold, according to the early observers, or certain organic com- 

 pounds, according to the author's own experiments. 1 



The latter reactions take place in various ways. Sometimes 

 the whole of the nitrogen of the nitric oxide is set free, libe- 

 rating -f 21 '6 more than the heat produced with free oxygen. 



1 " Chimie organique fondee sur la synthese," torn. ii. p. 485. 



