590 
DR. H. DEBUS ON THE CHEMICAL THEORY OE GUNPOWDER. 
It is worthy of notice that the points which represent, by their coordinates, the 
proportions of saltpetre, carbon, and sulphur in the gunpowders considered in this 
paper, are situated between two ordinates on our triangle BCD, for which respectively 
z assumes the values 5'5 and 8'7. The powders of Waltham Abbey, and Bunsen and 
Schischkoff’s sporting powder contain per 16 mols. of saltpetre, nearly the same 
amount of sulphur ; the former are represented by a point near the line D C, the 
latter by one near the line B D, of our figure BCD. 
Summary of the main results. 
1. The mean composition of the powders of Waltham Abbey can be represented by 
the symbols : 
16KN0 3 +21-18C+6-63S 
A powder of this composition is transformed in Noble and Abel’s apparatus according 
to the equation : 
16KN0 3 +2lC+5S=5K 2 C0 3 +K,S0 4 +2K 3 S 2 +13C0 3 +3C0 + 8N 3 . (II.) 
The residue of the sulphur, 1*63 atoms, unites partly with hydrogen, partly with the 
iron of the apparatus. 
2. The ordinary service and sporting powders contain for every 16 mols. of saltpetre 
from 13 to 22 atoms of carbon, and from 5'5 to 8*7 atoms of sulphur. 
3. A powder composed of pure carbon, saltpetre, and sulphur furnishes by its 
complete combustion potassic carbonate, potassic sulphate, potassic disulphide, carbonic 
acid, carbonic oxide, and nitrogen, as chief products. 
4. An increase of pressure appears, eater is paribus , to diminish the amount of 
carbonic oxide, and, in consequence, according to equation (VIII.), to increase the 
quantities of potassic carbonate, potassic disulphide, and carbonic acid, and diminish 
that of potassic sulphate. These fluctuations depending on pressure are, however, 
very small. In Noble and Abel’s Experiment No. 38, the pressure amounted to 
18'6 tons, in Experiment No. 77 to 31 '4 tons on the square inch, Experiment No. 38 
gave for every 16 mols. of decomposed saltpetre 3'36 mols. of carbonic oxide, and 
Experiment No. 77, 2'9 mols. of this gas, or, for a difference of 12'8 tons in pressure, 
one of 0'46 mol. of carbonic oxide. A diminution of 0'5 mol. of carbonic oxide corre¬ 
sponds to one of 0T43 mol. in the amount of potassic sulphate, and an increase of 
0‘071 mol. in that of the potassic carbonate and disulphide, and 0'428 mol. in the 
quantity of carbonic acid. These fluctuations are probably not caused directly by the 
pressure, but by the differences in the rate of cooling after explosion. 
5. The combustion of gunpowder takes place in two stages, one succeeding the 
other. 
(a.) A process of oxidation during which potassic sulphate, carbonate, carbonic acid 
