78 
CAPTAIN NOBLE AND MB. F. A. ABEL ON EIKED GUNPOWDEB, 
other oxidizable substances, and the existence also of a comparatively high proportion 
of oxygen in the gaseous products appear to indicate the occurrence of reactions in 
the course of the preparation of gas and residue, by the gradual deflagration of the 
powder, which were distinct from those attending the ordinary explosion of powder in 
a confined space. 
The very considerable differences between the results of our analyses and of the expe- 
riments of Bunsen and Schischkoff and of Linck appear therefore clearly ascribable 
to the fact that the deflagration of gunpowder, as carried out by them, cannot be 
expected to furnish results similar to those produced when a charge of powder is 
exploded in a. confined space under considerable pressure and in one operation. 
This conclusion receives support from the results of analysis of powder-residues 
published by Federow. Those products which he collected from a cannon in which 
3 lb. of powder were fired furnished analytical results much more nearly resembling 
those obtained by us than those of Bunsen and Schischkoff ; the proportion of sulphate 
was similar to that obtained in many of our experiments, and therefore very much 
below that of the German experimenters, while the proportion of sulphide was very 
considerably higher than the largest amount obtained by us — a result, we believe, not 
difficult of explanation. In the residue collected in a glass tube by firing small 
quantities of powder (blank charges) in a pistol, which therefore were not exploded 
under any considerable pressure, and were consequently subjected to more gradual 
change, the results were of very different nature, the proportion of sulphate being 
comparatively very high, and that of the sulphide very low. 
That the mode of operation pursued by Karolyi should have furnished results similar 
to those obtained by Bunsen and Schischkoff’s method is at first sight somewhat 
surprising, inasmuch as, by the arrangement which he adopted, the powder-charge was 
exploded in an envelope (a small thin shell) offering some amount of initial resistance. 
But as this explosion was accomplished in a capacious exhausted chamber, the pressure 
developed upon the first ignition of the charge suffered a sudden reduction at the moment 
that the shell was fractured, and most probably, therefore, before the entire charge 
had exploded. Hence it might have been expected that some portions of the oxidizable 
constituents of powder would escape oxidation, either entirely or partly, and that, at 
any rate, the oxidation of the sulphur would not be effected to the complete extent 
observed in operating according to Bunsen and Schischkoff’s plan. But it appears 
that in one instance not a trace, and in another only 0T5 per cent., of potassium 
sulphide was found in the solid products, the proportion of hyposulphite found being 
at the same time much smaller than that observed by Bunsen and Schischkoff; so that 
the sulphur-compounds obtained consisted chiefly of the highest product of oxidation, 
and yet in each of the two experiments nearly 4 per cent, of charcoal and a large 
proportion of hydrogen escaped oxidation altogether. In one experiment nearly 7 per 
cent, of sulphur appears to have been left in an uncombined state. 
In our experiments, in which the powder was exploded under more or less consider- 
able and sustained pressure, the complete oxidation of the sulphur might certainly be 
