CAPTAIN NOBLE AND ME. E. A. ABEL ON EIEED GUNPOWDEB. 
87 
thing approaching a precise expression of the chemical changes which gunpowder of 
average composition undergoes when exploded in a confined space, we feel warranted 
by the results of our experiments in stating, with confidence, that the chemical theory 
of the decomposition of gunpowder, as based upon the results of Bunsen and Schisch- 
koff, and accepted in recent text-books, is certainly as far from correctly representing 
the general metamorphosis of gunpowder as was the old and long-accepted theory, 
according to which the primary products were simply potassium sulphide, carbonic 
anhydride, and nitrogen. 
Moreover the following broad facts regarding the products furnished by the explo- 
sion of gunpowder appear to us to have been established by the analytical results 
given in this paper. 
1. The proportion of carbonic oxide produced in the explosion of a gunpowder in 
which the saltpetre and charcoal exist in proportions calculated, according to the old 
theory, to produce carbonic anhydride only, is much more considerable than hitherto 
accepted. 
2. The amount of the potassium carbonate formed, under all conditions (as regards 
nature of the gunpowder and pressure under which it is exploded), is very much larger 
than has hitherto been considered to be produced, according to the results of Bunsen 
and Schischkoff and more recent experimenters. 
3. The potassium sulphate furnished by a powder of average normal composition is 
very much smaller in amount than found by Bunsen and Schischkoff, Linck, and 
Karolyi. 
4. Potassium sulphide is never present in very considerable amount, though generally 
in much larger proportion than found by Bunsen and Schischkoff ; and there appears 
to be strong reason for believing that in most instances it exists in large amount as a 
primary result of the explosion of gunpowder. 
5. Potassium hyposulphite is an important product of the decomposition of gun- 
powder in closed spaces, though very variable in amount. It appears probable (as 
above pointed out) that its production is in some measure subservient to that of the 
sulphide ; and it may perhaps be regarded as representing, at any rate to a considerable 
extent, that substance in powder-residue — i. e. as having resulted, partially and to a 
variable extent, from the oxidation, by liberated oxygen, of sulphide, which has been 
formed in the first instance. 
6. The proportion of sulphur which does not enter into the primary reaction on the 
explosion of powder is very variable, being in some instances high, while, in apparently 
exceptional results, the whole amount of sulphur contained in the powder becomes 
involved in the metamorphosis. In the case of pebble powder, the mechanical con- 
dition (size and regularity of grain) of which is perhaps more favourable to uniformity 
of decomposition under varied conditions as regards pressure than that of the smaller 
powders, the amount of sulphur which remains as potassium polysulphide is very uni- 
form, except in the products obtained at the lowest pressure ; and it is noteworthy 
