CAPTAIN NOBLE AND MR. E. A. ABEL ON EIRED GUNPOWDER. 
85 
It will be seen on comparing our analytical results with the pressures recorded in 
the several experiments as being developed by the explosions, that the latter are not 
affected by very great differences in the composition of the products, or by important 
variations in the extent to which particular reactions appear to predominate over 
others. The pressures developed by explosion of the pebble and R. L. G. powders, 
under corresponding conditions as regards the relation of charge to total space, were 
almost identical up to the highest density ; and the same was the case with F. G. 
powder at the lower densities ; yet there were in several instances very considerable 
differences between the products formed from the different powders under the same 
pressures (or accompanied by the development of corresponding pressures), differences 
which were certainly not to be accounted for by the respective constitution of those 
powders. 
The composition of the gases and residues obtained in Experiments 8, 7, and 17, 
and 12, 11, and 19 (Tables III. & IV.) may be referred to in illustration of this. 
A cursory inspection of the analytical results at once shows that the variations in 
composition of the solid products furnished by the different powders, and even by the 
same powder under different conditions, are much more considerable than in those of 
the gaseous products ; and it is evident that the reactions which occur .among the 
powder-constituents, in addition to those which result in the development of gas, of 
fairly uniform composition (and very uniform as regards the proportions which it bears 
to the solid), from powders not differing widely in constitution from each other, are 
susceptible of very considerable variations, regarding the causes of which it appears 
only possible to form conjectures. 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 therefore 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, while it would, in reality, possess no important bearing upon an 
elucidation of the theory of explosion of gunpowder. 
The extensive experiments which the Committee on Explosive Substances has insti- 
tuted, with English and foreign gunpowders of very various composition, have con- 
clusively demonstrated that the influence exerted upon the action of fired gunpowder 
by comparatively very considerable variations in the constitution of the gunpowder 
(except in the case of small charges applied in firearms) is often very small as compared 
with (or even more than counterbalanced by) the modifying effects of variations in the 
mechanical * and physical properties of the powder ( i . e. in its density, hardness, the 
* The desirability of applying these means to effecting modifications in the action of fired gunpowder was 
pointed out by Colonel Boxer in a memorandum submitted to the War Office in 1859 ; and the first Govern- 
ment Committee on Gunpowder, soon afterwards appointed (of which Colonel Boxer and Mr. Abel were mem- 
bers), obtained successful results, which were reported officially in 1864, by limiting the alterations in the 
manufacture of gunpowder intended for use in heavy guns to modifications in the form, size, density, and 
