88 
CAPTAIN NOBLE AND ME. E. A. ABEL ON EIEED GUNPOWDEE. 
that with R. L. G. powder, under the same conditions, comparatively little sulphur 
escapes ; while in the case of F. G. powder, under corresponding circumstances, there 
is no free sulphur at all. 
7. But little can be said with regard to those products, gaseous and solid, which, 
though almost always occurring in small quantities in the products, and though appa- 
rently, in some instances, obeying certain rules with respect to the proportion in which 
they are formed, as already pointed out, cannot be regarded as important results of the 
explosion of powder. It may, however, be remarked that the regular formation of 
such substances as potassium sulphocyanate and ammonium carbonate, the regular 
escape of hydrogen and sulphydric acid from oxidation, while oxygen is occasionally 
coexistent, and the frequent occurrence of appreciable proportions of potassium nitrate, 
indicate a complexity as well as an incompleteness in the metamorphosis. Such com- 
plexity and incompleteness are, on the one hand, a natural result of the great abrupt- 
ness as well as the comparative difficulty with which the reactions between the 
ingredients of the mechanical mixture take place ; on the other hand, they favour the 
view that, even during the exceedingly brief period within which chemical activity 
continues, other changes may occur (in addition to the most simple, which follow im- 
mediately upon the ignition of the powder) when explosions take place at pressures 
such as are developed under practical conditions. 
The tendency to incompleteness of metamorphosis, and also to the development of 
secondary reactions under favourable conditions, appears to be fairly demonstrated by 
the results obtained in exploding the different powders in spaces ten times that which 
the charges occupied (experiments 8, 1, and 16). It appears, however, that, even 
under apparently the most favourable conditions to uniformity of metamorphosis 
(namely in explosions produced under high pressures), accidental circumstances may 
operate detrimentally to the simplicity and completeness of the reactions. But the 
fact, indisputably demonstrated in the course of these researches, that such accidental 
variations in the nature of the changes resulting from the explosion do not, even when 
very considerable, affect the force exerted by fired gunpowder, as demonstrated by the 
recorded pressures, &c., indicates that a minute examination into the nature of the pro- 
ducts of explosion of powder does not necessarily contribute directly to a comprehen- 
sion of the causes which may operate in modifying the action of fired gunpowder. 
G. VOLUME OE THE PEEMANENT GASES. 
The results of the experiments made to determine the quantity of permanent gases 
generated by the explosion of the three service-powders which we have employed are 
given in Nos. 58 to 62 and 64. 
From a discussion of these results it appears that, in the case of pebble powder, the 
combustion of 386-2 grammes gave rise respectively to 106,357-8, 105,716-2, and 
107,335-8 cub. centims. of gas at a temperature of 0° C. and a barometric pressure of 
760 millims. ; or, stating the result per gramme of powder, the combustion of 1 gramme 
