386 EXPLOSIVE GASES A.ND DETONATING GASEOUS MIXTURES 



8. The detonation of cyanogen caused by fulminate (p. 71) 

 corresponds to the following effects : 

 Heat liberated, 



Q = 74-5 CaL for C 2 N 2 (52 grms.) ; 

 temperature developed at constant volume, 



t = 7600; 

 pressure produced, 



p = 28-8 atm. 



In these calculations it is supposed that the molecular heat 

 of solid carbon is equal to that of gaseous oxygen at constant 

 volume. 



We see from these figures that the temperature developed 

 and the pressure produced by acetylene and cyanogen would 

 exceed the effects produced by all other explosive gases, even if 

 we take into consideration the solid state of the carbon. 



2. DETONATING GASEOUS MIXTURES. 



1. Chlorine and oxygen are the only simple gases which can 

 supply explosive gaseous mixtures by their association with 

 combustible gases, hydrogenated or carburetted. Among the 

 compound gases, the chlorine and nitrogen oxides share this 

 property. 



2. In the following table the characteristic data have been 

 given for the principal detonating gaseous mixtures constituted 

 by these various gases, whether combustive or combustible. 



Here the heat liberated results from the formation of certain 

 compound bodies ; consequently the maximum pressure, calcu- 

 lated theoretically, might be considerably diminished in practice, 

 owing to dissociation. It might also be diminished owing to 

 the variation of the specific heats. We shall revert to this 

 subject later on, but first give the theoretical values. 



3. According to this table, the maximum work which can be 

 accomplished by one kgm. of the various explosive gases, work 

 which is in proportion to the heat liberated, that is, the 

 potential energy of these mixtures, varies only from single to 

 double for gases containing carbon and hydrogen mixed with 

 pure oxygen (the water being supposed to be gaseous). 



Moreover, this work is nearly the same for the various 

 hydrocarbon gases. 



Such work exceeds, moreover, that of all the solid or liquid 

 explosive compounds taken under the same weight. With 

 hydrogen and oxygen, for instance, it is four times as great as 

 that of ordinary powder, and twice as great as that of nitro- 

 glycerin. 



