DR. H. DEBUS ON THE CHEMICAL THEORY OE GUNPOWDER. 
555 
Saltpetre. 8 O'31 
Sulphur.7’ 95 
Charcoal ..11'74 
Sporting powders are required to bum quickly, and the composition of some of them 
approaches very closely to these theoretical values. 
Saltpetre. 
Sulphur. 
Charcoal. 
English*. 
79-7 
7-8 
12'5 
French.. 
78'0 
10*0 
12*0 
Bunsen and Schischkoff’s powder. 
78'99 
9'84 
11*17 
Sporting powder in the year 1546 . 
83'4 
8'3 
8'3 
The heat relations of the products of explosion, as represented by equation 
16KN0 3 + 13C+5S= 3K 3 C0 3 + Sl^SO^d^CC^d-CO-j-UlSI^, 
are of special interest. 
If we assume for the heat of formation of potassic carbonate, potassic sulphate, and 
carbonic acid the following values—- 
K 3 CO 3 =279540 cal. 
K2S0 4 = 344640 „ 
C0 3 = 9.7000 „ 
we obtain 
3X279540= 838620 
5X344640 = 1723200 
9 X 97000= 873000 
838620 : 1723200 : 873000=1 : 2'05 : 1*04 
or nearly 1:2:1 
ratios which are very remarkable. 
The total amount of heat produced by the combustion of 16KN0 3 -f-13C+5S 
according to equation (IV.), Is =1563189 cal. The maximum amount of heat is 
produced by a mixture which contains for every 16 mols. of saltpetre 8 atoms of 
carbon and 8 atoms of sulphur, according to the equation : 
16KN0 3 +8C+8S= 8K 2 S0 4 +8C0 2 +8N2 
and amounts to 1621450 cal. 
Therefore, if the combustion of ordinary service powder takes place during the first 
stage according to equation (IV.), nearly the maximum quantity of heat is obtained 
which a mixture of saltpetre, sulphur, and carbon can produce. If the question were 
* Graham-Otto, £ Lehrbuch der Chemie,’ iv. edit., ii., p. 211. 
