208 CAPTAIN NOBLE AND MR. E. A. ABEL ON FIRED GUNPOWDER. 
A careful examination into the nature and proportions of the products furnished 
by the explosion of three descriptions of service gunpowder, differing but little in 
composition from each other, and by one and the same sample of powder under different 
conditions as regards pressure (or space in which the explosion took place), led us to the 
conclusion, which it may be as well to repeat in the precise terms used in our former 
memoir, namely, that “any attempt to express, even in a comparatively complicated 
chemical equation, the nature of the metamorphosis which a gunpowder of average 
composition may be considered to undergo when exploded in a confined space, would 
. . . . only be calculated to convey an erroneous impression as to the simplicity or the 
definite nature of the chemical results, and their uniformity under different conditions ” 
(p. 85). 
In giving expression in the foregoing terms to this conclusion, we certainly did not 
intend to convey the impression, nor do we consider that our words are at all suscep¬ 
tible of the interpretation, that it was impossible to put into some form of equation 
(as was done, for instance, by Bunsen and Schischkofe in the case of the analytical 
results arrived at by them), a representation of a variety of reactions, which if assumed 
to take place simultaneously among different proportions of the powder-constituents, 
might express results approximating to one or other of the analytical results obtained 
by us, and might thus afford some approximate theoretical representation of the meta¬ 
morphosis of gunpowder when fired in closed vessels. 
But the very great variations in composition (of the solid portion more especially) of 
the products of explosion of samples of gunpowder presenting only small differences in 
constitution, afforded, in our opinion, most conclusive proof that the reactions which 
occur among the powder constituents are susceptible of very considerable variations, 
regarding the causes of which it appears only possible to form conjectures, and that 
consequently “ no value whatever can be attached to any attempt to give a general 
chemical expression to the metamorphosis of gunpowder of normal composition.” 
In one of the series of interesting communications made by M. Berthelot to the 
Academie des Sciences in 1876/" as contributions to the “History of Explosive 
Agents,” that chemist gives to our conclusions, as expressed in our former memoir, an 
interpretation which, as above pointed out, they certainly cannot be considered to bear, 
when lie says we have stated that the variations in the proportions of the principal 
products of explosion are opposed “ to all general chemical representation of the 
metamorphosis produced by the explosion,” an opinion contrary, as he states, to all 
that is known in chemistry. Starting with the above assumption of the nature of our 
views, M. Berthelot proceeds to demonstrate that, in order to account for the forma¬ 
tion of the chief products in some particular proportion in which potassium sulphate is 
so small as to allow of its being neglected, the powder-constituents must be presumed 
to react upon each other simultaneously, in prescribed proportions, according to three, 
or, if the sulphate amount to 12 or 14 per cent., according to four out of fve different 
* ‘ Comptes Rendus,’ tom. lxxxii., p. 400. 
