562 DR. H. UK BUS ON THE CHEMICAL THEORY OF GUNPOWDER. 
If the potassic hyposulphite is replaced by its equivalent of potassic disulphide, the 
quantities of the chief products expressed in molecular weights, and calculated for 
16 mols. of decomposed saltpetre, we obtain : 
1-97KoCO 3 +5-25K. 2 SO 4 +0-45K 2 S 2 +10-59CO 2 +7-7N 2 +0-33K 3 S + 0-71OO. 
From these symbols we calculate the following composition of the powder : 
16KNO 3 + 13-2C+G-48S+0-66O. 
If now we substitute, in equation (VIII.), for x the number 16, for y 13‘2, for z 6*5, 
and for a 0'7l, w r e find for the chief products : 
2-25K 3 CO 3 + 5-0lK 2 SO 4 +0-74K 2 S 2 +10-25CO 2 +0-70CO + 8N 2 
numbers which closely agree with those found by experiment. 
The powder used by Bunsen and Schischkoff contains, according to analysis : 
16KN0 3 +13-3C+6-3S 
a composition which is nearly the same as that deduced from the chief products of 
combustion. 
The analytical method in this case causes no appreciable error in the determination 
of the potassic sulphate. Neither, according to my own analysis, does potassic 
monosulphide, nor, according to Noble and Abel’s analysis of the residues of mining 
powder, does potassic disulphide produce potassic sulphate by treatment with cupric 
oxide. Bunsen and Schischkoff’s residues contained a mixture of mono- and 
disulphide, and of both only a comparatively small quantity. 
Ltnck* examined the products of combustion of the W tirtemberg service powder 
according to the method employed by Bunsen and Schischkoff. He obtained the 
following results:— 
Composition of the powder— 
Saltpetre . 
. 07470 
Sulphur 
.0-1245 
Charcoal— 
Carbon . . 
. 0*0905 
Hydrogen . 
. 0-0041 
Oxygen . . 
. 0-0278 
Water . 
. 0-0060 
0-9999 
* Ann. der Cliemie und Pliavtn., Bd. cix., p. 53. 
