522 POWDERS WITH CHLORATE BASE. 



equivalent of salt, or - O9 Cal. per equivalent of oxygen, instead 

 of liberating it. 



From this point of view, therefore, the perchlorate acts almost 

 like free oxygen, with the disadvantage of half of it being 

 useless inert matter. 



Pure perchlorate is not explosive either by shock or inflam- 

 mation, as the chlorate. Further, its mixtures with organic 

 substances are far less sensitive to shock, friction, the action 

 of acids, etc. They ignite with more difficulty and burn 

 slower. 



2. CHLOEATED POWDERS PROPERLY so CALLED. 



1. Potassium chlorate powder was formerly manufactured in 

 the following proportions : 



Chlorate 75-0 



Sulphur 12-5 



Charcoal 12-5 



This powder is extremely shattering and easy to ignite ; its 

 preparation has occasioned terrible accidents, but the true 

 reaction which it develops is not well known. The above 

 proportions correspond to the following weights : 



3C10 3 K + 2S + 50, 



assuming the weight of pure carbon equal to that of charcoal, 

 which however is not exact (see p. 488). 



It was first supposed that the reaction consists in the trans- 

 formation of this system into the following bodies : 



3KC1 + 2S0 2 4- 500. 



The presence of sulphurous acid is unquestionable at any 

 rate, but carbonic acid is also produced, which the equation 

 does not take into account. 



The same uncertainty prevails concerning the numberless 

 mixtures formed by potassium chlorate, whether pure or 

 mixed with nitrate, these bodies being associated with com- 

 bustible substances, such as charcoal, sugar, ferrocyanide, tan, 

 wood sawdust, gamboge, benzene, sulphur, carbon disulphide, 

 antimony sulphide, and the metallic sulphides, phosphorus and 

 the phosphides, etc., all these being mixtures which have been 

 proposed or patented of late years, both as explosives and fuses. 

 We shall give the theoretical calculations only for the total 

 combustion mixtures formed by the association of potassium 

 chlorate with carbon, sulphur, sugar and yellow prussiate, for 

 the sake of comparison between them, and the analogous 

 mixtures formed by potassium nitrate. 



