CAPTAIN NOBLE AND ME. F. A. ABEL ON FIBED GUNPOWDER. 
79 
expected to have been favoured to a much greater extent than in Karolyi’^ experi- 
ments; yet in all but one experiment, made with a powder of exceptional composition, 
the proportion of sulphate formed was very greatly below that found by Karolyi. 
The irreconcilable nature of Karolyi’s analytical results, though probably in some 
measure ascribable to the exceptional conditions under which he obtained his products, 
does not appear satisfactorily accounted for thereby. 
On examination and comparison with each other of the analytical results given in the 
foregoing Tables, the following points suggest themselves : — 
Excluding the results of a few explosions of marked exceptional character as regards 
the solid products furnished, and those produced under the lowest pressure, which were 
naturally expected to yield variable and discordant results, there is considerable 
similarity, not only between the products furnished by pebble powder when exploded 
under different conditions as regards pressure, but also between the results obtained 
with this powder and with the sample of R. L. G. powder employed in the experi- 
ments, which did not differ greatly in composition from it. The proportion of carbon 
was slightly lower in the R. L. G. than in the pebble powder ; and this fact is in harmony 
with the proportion by weight which the total gaseous constituents bear to the solid 
in the products obtained with the two powders, it being somewhat the highest, in 
most instances, in the case of the pebble powder. The proportion of carbonic oxide is 
often rather higher in the gas obtained from the pebble powder than in that furnished 
by the R. L. G. powder ; and this is in accordance with the fact that the proportion of 
carbon is somewhat higher, while that of the saltpetre is a little lower, in the former 
than in the latter. Excluding the results furnished by the experiments in which the 
powder was, exploded in the largest space (in which, therefore, the gases were deve- 
loped at the lowest pressures) it will be observed that with the slowest-burning- 
powder (the pebble) the proportion of carbonic oxide decreases steadily, while that of 
the anhydride increases, in proportion to the pressure developed at the time of explosion. 
The proportion of carbonic anhydride is about the same in the gas from the two 
gunpowders specified ; but that of the potassium carbonate is somewhat different, and 
appears regulated by circumstances other than the composition of the powder, being- 
highest in the residues furnished by the R. L. G. powder at the higher pressures, and 
lowest in those of the same powder furnished at lower pressures. The amount of 
carbonate furnished by the pebble powder under different conditions as to pressure 
varies, on the other hand, comparatively little, except at the highest pressure*. 
The occasional occurrence of a small quantity of marsh-gas, like that of oxygen, is 
evidently an accidental result, being observed in some instances in the products 
obtained at low pressures, and the reverse in other instances. 
In the gaseous products from the F. G. powder formed at pressures up to 50 per 
* In 90 per cent, space the amount of carbonate formed was nearly equal to the proportions found in the 
residues from E. L. G. produced at the higher pressures. — February 1875. 
