

BOOK III. 



FORCE OF EXPLOSIVE SUBSTANCES IN 

 PARTICULAR. 



CHAPTER I. 



CLASSIFICATION OF EXPLOSIVES. 



1. DEFINITION OF EXPLOSIVES. 



1. ANY system of bodies capable of developing permanent gases 

 or substances which assume the gaseous state in the conditions 

 of reaction, such as water above 100, mercury above 360, etc., 

 may constitute an explosive agent. Even gaseous bodies assume 

 the same character if compressed beforehand, or if their volume 

 increases in consequence of some transformation. For this 

 purpose it is not necessary that the temperature of the system 

 should rise, although this condition is generally fulfilled and 

 tends to increase the effects. 



2. Nevertheless, this definition of explosive agents, although 

 exact from an abstract point of view, is too wide for practice, 

 which only utilises such systems as are susceptible of a rapid 

 transformation and accompanied by the liberation of great 

 heat. 



3. Moreover, the initial system should be able to subsist of 

 itself, at least for some time ; its transformation only taking 

 place if provoked by some external circumstance, such as fire, 

 shock, friction, or again by the intervention of small quantities 

 of a chemical agent, acting either in consequence of its own 

 reactions, which propagate themselves chemically (sulphuric 

 acid in presence of potassium chlorate mixed with organic sub- 

 stances), or because it produces a sudden shock, determining by 

 its mechanical effects the production of the explosive wave 

 (p. 88) and general explosion. 



