72 DURATION OF EXPLOSIVE REACTIONS. 



nitro-diazobenzene was different under circumstances in which 

 the detonator is destroyed at a slight pressure, from its decompo- 

 sition in the calorimetric bomb under a high pressure, as 

 observed by Vieille and the author. Instead of obtaining all the 

 oxygen from the compound in the state of carbonic oxide at the 

 same time as free nitrogen and a nitrogenous carbon of a very 

 porous and dense nature, on this occasion, along with the 

 nitrogen, only one-fourth of the volume of the theoretical car- 

 bonic oxide was observed, along with some phenol and a tarry 

 substance. 



6. Nitric oxide. This body explodes under the influence of 

 mercury fulminate, but the phenomenon is more complicated 

 than with the former gases, the carbonic oxide produced by the 

 fulminate burning, at the expense of the oxygen of the nitric 

 oxide, to form carbonic acid. This combustion appears to have 

 taken place at the expense of free oxygen, and not of nitric per- 

 oxide formed transitorily. In fact, the mercury is not attacked, 

 contrarily to what always happens when this gas appears for a 

 moment. 



We therefore have, 



NO = N + 

 CO + = C0 2 . 



The combustion even of carbonic oxide is characteristic, for 

 nitric oxide, mixed with carbonic oxide, does not explode either 

 by simple inflammation, or by the electric spark. 



7. Arseniuretted hydrogen. Arseniuretted hydrogen has ex- 

 ploded under the influence of the fulminate, and has become 

 absolutely resolved into its elements, arsenic and hydrogen. 



AsH 3 = As + H 3 . 



8. Here will be given experiments on the sudden decomposi- 

 tion of nitrogen monoxide into nitrogen and oxygen. This 

 decomposition, which liberates -f 20,600 cal. (N 2 = 44 grins.), 

 may be caused by the sudden compression of 30 c.c. of this 

 gas reduced to ^^ of their volume by the sudden fall of a ram 

 weighing 500 kgms. 1 



On the other hand, nitrogen monoxide only decomposes 

 gradually under the influence of progressive heat or of electric 

 sparks. 



9. All these tests are in reference to gases. But solid or 

 liquid eridothermal combinations offer the same variety. While 

 nitrogen chloride and iodide explode under the influence of a 

 slight heat, or of slight friction, nitrogen sulphide requires to be 

 heated up to 207, or requires violent concussion, in order to 

 explode and to become resolved into its elements. It then 

 liberates 4- 32,300 cal. (NS 2 = 46 grms.), according to tests 

 which the author has made along with Vieille. 



1 " Annals de Chimie et de Physique," 5 e s&ie, torn. iv. p. 145. 



