140 GENERAL PRINCIPLES OF THERMOCHEMISTRY. 



TABLE XX. HEAT OF VOLATILIZATION (LATENT HEAT) OF THE ELEMENTS AND 

 THEIR PRINCIPAL COMPOUNDS, REFERRED TO THE SAME GASEOUS VOLUME 

 (22'32 LITRES) UNDER ATMOSPHERIC PRESSURE. 



The calculation of the pressures exerted at the moment of 

 decomposition of an explosive substance, requires not only the 

 knowledge of the heat disengaged by the transformation, but 

 also that of the specific heat of the products of the explosion 

 and their volume. It is equally necessary to know the specific 

 heat of the component bodies, in order to know the effects of a 

 certain heating on these bodies. Finally, the volume which 

 they occupy for a given weight, and which is deduced from 

 their density, plays an essential part in the valuation of the 

 density of charge and specific pressure (p. 28). These con- 

 siderations have induced the author to give the following 

 tables : 



