498 



POWDERS WITH A NITEATE BASE. 



allow this oxygen to recombine with the excess of carbon or 

 sulphur. 



13. Hydrogen and methane are unimportant products, due to 

 the complex composition of the charcoal. 



The sulphocyanide appears to result from the action of the 

 sulphur on a small quantity of potassium cyanide, which may 

 be formed, as is well known, in the reaction of carbon in excess 

 on potassium nitrate. 



A portion of this cyanide changed into cyanate by the 

 oxidising action, then decomposed by water vapour during 

 cooling, appears to be the origin of the ammonium carbonate. 



The same reaction of water vapour and the co-existing car- 

 bonic acid on the alkaline sulphide explains the formation of a 

 small quantity of sulphuretted hydrogen. 



14. Equivalent relations. If, for the sake of simplicity, the 

 accessory products (sulphuretted hydrogen, methane, hydrogen, 

 sulphocyanide, oxygen, ammonium carbonate, etc.) be neglected, 

 we find the following equivalent relation between the principal 

 products : 



POWDER. 



The general mean of the analyses would not differ greatly 

 from the following relation proposed by Debus : 



16KN0 3 + 21C -f 7S == 13C0 2 + SCO -f 5K 2 C0 3 +K 2 S0 4 

 + 2K 2 S 3 -f 16N. 



15. Variations in, the composition of the final products. But 

 this mean does not take into account the variations amounting 

 in the case of carbonic oxide to from 2 '6 to 5'8 ; in that of 

 potassium carbonate from 251 to 38'0 ; the sulphate from 2'8 

 to 14'0 ; the sulphide from 4*7 to 12'5. 



Generally speaking, the amount of carbonic acid and 

 potassium carbonate increases slightly (except F.G., W.A. for the 

 latter) with the pressure ; while the carbonic oxide tends to 

 diminish (except E.G., W.A.). 



The potassium sulphate, sulphide, and carbonate must contain 

 the whole of the potassium. Hence no one of these three salts 

 can vary without the whole of both the others undergoing a 



