DR. H. DEBUS ON THE CHEMICAL THEORY OE GUNPOWDER. 
593 
The mixture containing : 
I 6 KNO 3 + 8 C+ 8 S 
produces the greatest amount of heat and the smallest quantity of gas, and the 
mixture represented by the symbols : 
16KN0 3 +24C+16S 
the largest volume of gas and the smallest quantity of heat. 
12 . The product E obtained by the multiplication of Y and W (equations IX. 
and X.) will approximately represent the relative energies of mixtures of various 
composition. 
The mixture represented by the symbols 
16KN0 3 + 24C-j-16S 
is of all the infinite number of mixtures which can transform themselves according to 
equation (XIII.) the one for which E assumes the greatest value. Hence, a powder of 
this composition possesses the greatest energy. 
13. If a mixture of saltpetre, carbon, and sulphur were required which shall possess 
nearly the greatest energy, and at the same time contain the smallest amounts of 
carbon and sulphur compatible with this condition, theory would point to the mixture : 
I 6 KNO 3 + 22 C+ 8 S 
The service powders of most nations fluctuate about : 
16EN0 3 +21-20+6-6S 
14. Gunpowder, however, does not contain pure carbon, but besides this element 
hydrogen and oxygen as constituents of the charcoal. 
The oxygen is eliminated with a portion of the hydrogen in the form of water, the 
remainder of the hydrogen remains either free or unites with carbon, sulphur, and 
nitrogen respectively, producing sulphuretted hydrogen, ammonia, and marsh gas. 
These secondary products only amount from 1 to 2 per cent, of the powders. 
15. Mining powders contain much more carbon than is required according to equa¬ 
tion (XIII.). In consequence, the oxygen of the charcoal is not eliminated during the 
combustion of these powders with hydrogen, as water, but in combination with carbon 
as carbonic oxide and carbonic acid. 
The hydrogen thus left free causes the formation of a comparatively large proportion 
of sulphuretted hydrogen and marsh gas. The potassic sulphocyanate is also produced 
in quantities much larger than those formed by the service powders on account of 
the carbon left free at the end of the combustion. If we neglect these secondary 
products, then the combustion of mining powder may be represented by the simple 
equation : 
16KNO 8 +280 + 8S=4K 8 CO 3 + 4K a S a +12CO 8 +12CO + 8 N a 
4 e 2 
