PRACTICAL EXPLOSIVES 109 



If ozone is used instead of oxygen the effect is markedly 

 increased : 



CS 2 + 2O 3 = C0 2 + 2 S0 2 , W = 26l + 2 X 36 = 333, 



C 2 H 2 + |0 3 =2C0 2 + H 2 0, W = 316 + ^x36 = 376, 



so that a liquid mixture of acetylene and ozone might be 

 expected to form one of the most effective explosives. 



Four elements. Yet another possibility may be added to 

 the above, since two pairs of elements in the form of com- 

 pounds AB and CD, which each decompose with evolution 

 of heat, might be so chosen as to yield two, AC and BD, 

 with the largest possible heat of formation. An example 

 of this may be derived from what precedes 



4 C1 2 + C 2 H 2 = 2 C0 2 + 2 HC1 + 3 C1 2 , 



W= 2(22 + 97) + 4Xi8 + 53 = 363. 



(c) Practical Explosives l . 



The materials remarked on above as being suitable on 

 thermal grounds, some of which exceed in effect the explo- 

 sives so far made use of, are nevertheless often unsuitable 

 on account of the great danger in handling them, so that 

 for practical purposes we must add safe handling as a 

 further condition. We will consider from this point of 

 view, solid and liquid mixtures, and more complex com- 

 pounds in order. 



(a) Solid mixtures. (Black gunpowder.) Solid mixtures 

 are usually fairly safe, because, in the solid state, the 

 homogeneity of the mixture, and the contact between the 

 components, are never complete ; the former may be im- 

 proved by fine grinding, the latter by compression, or 

 preliminary fusion and solidification. The most important 

 substance belonging to this category is ordinary gun- 

 powder, made of sulphur, carbon, and nitre. The me- 



1 Guthmann, Die Explosivstoffe, 1895. 



