DISADVANTAGES OF CHLORATE POWDERS. 541 



characteristic data of each of these equations is estimated, and 

 it is shown that they represent all the observed phenomena. 



In the case of blasting powder we must also consider the 

 transformation of carbonic acid into carbonic oxide. 



Powders with a sodium or barium nitrate base are then 

 considered, but bearing in mind this circumstance, that chemical 

 reactions referred to equivalent weights ought to liberate 

 approximately the same quantities of gas- and heat as powder 

 with a base of potassium nitrate, yet that at the same weight 

 sodium nitrate is superior, whereas barium nitrate would be 

 less favourable. 



9. We conclude by the examination of powders with a 

 potassium chlorate base, and we show how these powders 

 possess a force superior to those with a base of nitrate, seeing 

 that they liberate more heat and at least an equal volume of 

 gas, but they are very inferior to dynamite and gun-cotton. 



They are besides much more dangerous, owing to the 

 extreme facility with which they inflame under the influence 

 of shock or friction, and on account of their shattering proper- 

 ties ; the theory of all of which circumstances is accounted for, 

 and which circumstances explain the numerous accidents pro- 

 duced in manufacturing experiments, and the use of chlorate 

 powders made at different periods. Such powders, being also 

 surpassed by dynamite and gun-cotton, do riot offer any special 

 advantage to compensate for the exceptional dangers attending 

 their preparation and application. 



