CAPTAIN NOBLE AND MR. F. A. ABEL ON FIRED GUNPOWDER. 
209 
theoretical reactions, which, if assumed to occur simultaneously, in variable proportion 
and number, M. Berthelot regards as satisfactorily explaining (“ and definitely 
reducing to five simple reactions”) the formation of carbon dioxide, carbon oxide, 
potassium sulphate, sulphide and carbonate, from a powder of what we call normal 
composition." 
After giving further equations which apply to the extreme results (in regard to the 
chief products only) assumed to be obtainable from the introduction, on the one hand, 
of excess of saltpetre, on the other, of excess of charcoal, into the composition of 
powder, M. Berthelot passes to what he terms the accessory products and, excluding 
from these potassium hyposulphite, which he deals with separately, he first gives two 
equations to account for the production of sulphocyanide ; then two more to explain 
the existence of ammonium sesquicarbonate (which he believes to be formed by the 
action of water-vapour on potassium cyanide). The existence of sulphuretted or free 
hydrogen are explained by two more equations, and marsh gas is assumed to result 
from “the pyrogenous decomposition of the charcoal in the powder.” Lastly, an 
equation is given to account for the possible formation of traces of hyposulphite, 
which Berthelot however regards entirely as a product formed during the collection 
and analytical treatment of the solid residue, but which we nevertheless believe we 
* The five simple reactions in question are thus explained:— 
1. N0 6 K+S + C 3 =K.S.+3C0 2 + N. 
2. „ „ „ =k.c.o 3 lc6. + co 3 + n + s. 
3. „ „ „ =KC0 3 + liC0. 2 + N + S + iC. 
4. „ „ „ =KS0 4 + 2C0. + N+C. 
5. „ ,, ,, =KS0 4 +C0. 2 + N + C 2 . 
When sulphate is formed in such small quantities that it may be neglected, the simultaneous reactions 
supposed to occur are 1, 2, and 3, by quantities of the powder proportionate to the numbers r and 
but when the sulphate amounts to 12 or 14 per cent., the simultaneous reactions supposed to occur are 
Nos. 1, 3, 4, and 5, with quantities of powder corresponding to the numbers -g-, about 4, v, and -jV-. As 
there is only one single instance out of twenty-nine analyses of powder residues in which the sulphate was 
found to amount to as little as 4'6 per cent, of the solid products (the next lowest proportion being 
nearly double that amount), it can scarcely be assumed that M. Berthelot’s first arrangement of 
reactions can represent any but a most exceptional result. Again, the acceptance of his arrangement of 
four equations in the proportions he indicates as accounting for the formation of the chief products when 
the sulphate amounts to 12 or 14 per cent, of the total constituents, involves the assumption that a some¬ 
what considerable proportion of charcoal should remain uuoxidised ; in fact, nearly 2’5 per cent, of 
carbon should be found in the residue. The detection and determination of such a constituent of powder- 
residue does not involve any difficulty, yet there were only three instances out of eighteen residues (in 
which the sulphate was considerable in amount) where the charcoal was present in estimable quantities ; 
in two of these it was below 1 per cent., in the other it was only O'Ol per cent. In a few other residues 
only traces of charcoal were discovered ; the larger number contained none. 
These points are referred to in illustration of how imperfectly M. Berthelot’s not very simple arrange¬ 
ment of theoretical reactions correspond to the results actually obtained, even so far only as the chief 
products are concerned. 
MDCCCLXXX. 
o 
F, 
