552 
DR. H. DEBUS ON THE CHEMICAL THEORY OF GUNPOWDER. 
Noble, Abel, and Karolyl but is also in perfect accordance with the thermo- 
chemical relations of the products of explosion. 
The heat of formation of a molecule of potassic sulphate is much greater than that 
of one of potassic sulphide, hence, the production of the former is to be expected 
during explosion. In short, the formation of the molecules of potassic carbonate, 
potassic sulphate, and carbonic acid is accompanied by the greatest evolution of heat. 
Karolyi examined the products of explosion according to Bunsen and Schisch- 
koff’s method, which does not yield exact values for potassic sulphide and sulphate. 
The errors arising from this source will, however, be very small, if the potassic 
sulphide in the original powder residue is small. The small amount of potassic hypo- 
sulphite found by Karolyi proves that the products of combustion contained, in his 
experiments, very little potassic sulphide. As the potassic hyposulphite must be 
regarded as a product of oxidation of the potassic sulphide, it has been replaced in 
the following calculations by its equivalent of potassic sulphide. Nevertheless, the 
quantity of the latter does not exceed 0"32 of a molecule, hence the error caused by 
the method of analysis may be neglected. 
We will now take the chief products of explosion observed by Karolyi, and 
calculate from their composition the quantities of powder constituents which took part 
in their formation, and arrange the results in form of equations. 
Cannon powder. 
Bifle powder. 
3-C5 K 3 C0 3 ^ 
* 
" 16 KN0 3 
3-30 K 3 C0 3 " 
" 16 KN0 3 
4-62 K 3 S0 4 
14-32 C 
4*49 k 2 so 4 
15-94 C 
0-33 K 3 S 3 
II 
5-28 S 
0-20 K 3 S 3 
>=< 
4-89 S 
9-23 C0 3 
-0-9 N 
11-49 C0 3 
3-99 O 
2*04 CO 
0-13 0 
1-15 CO 
7-55 N 2 
L 
8-00 N 3 
The entire quantity of saltpetre contained in the powders taken for these experi¬ 
ments was decomposed, and its constituents, with the exception of very small 
quantities of potassium and nitrogen, in potassic sulphocyanate and ammonia, 
reappear in the above chief products. The cannon powder contains for every 
16 mols. of KN0 3 about 3 atoms of sulphur more than the rifle powder (p. 549). 
Nevertheless, during the first stage of the combustion the quantities of sulphur 
consumed in the formation of potassic sulphate are nearly the same in the experi¬ 
ments with both powders, and the potassic carbonate and disulphide are also almost 
identical. 
The ratios of the oxygen in the potassic carbonate, sulphate, and carbonic acid are 
as follows :— 
