80 
CAPTAIN NOBLE AND ME. F. A. ABEL ON FIEED OUNPOWDEE. 
cent, space, the carbonic oxide existed in proportions similar to those furnished by the 
R. L. G. powder. If the relative proportions of potassium nitrate and carbon in the 
powders furnished an indication of the proportions in which this gas should be formed, 
this particular powder should have furnished a higher proportion of carbonic oxide than 
the R. L. G., as it contains 0’5 per cent, more carbon and 1*4 per cent, less saltpetre 
than the latter; but then the proportion of sulphur in it is lower by 0'25 per cent.; 
moreover the charcoal in the F. G. was less highly burned, and therefore more rapidly 
oxidizable, a circumstance which may have a decided influence upon the amount of 
carbonic oxide produced by the explosion of gunpowder, distinct from that exerted by 
the proportion in which the ingredients exist. The difference in the amounts of 
carbonic oxide produced from this powder at the lower and the higher pressures is more 
marked than in the case of the other powders, the quantity in this as in the pebble 
powder decreasing decidedly as the pressure increases. The amount of carbonic anhydride 
which it furnished at the highest pressure (the powder occupied 90 per cent, of the 
space) is the largest found in any of the gaseous products*; but that produced when 
the powder occupied 70 per cent, of the total space was very nearly as high, while the 
amount obtained in the intermediate experiment (80 per cent, space) was decidedly 
lower, and corresponded closely to the proportions produced at the same pressure 
from R. L. G. and pebble powder. 
In the experiments with P. and R. L. G. (excluding the explosions in 10 p. c. space) 
the amount of sulphuretted hydrogen was highest at the lowest pressures ; in the case 
of R. L. G. powder the proportion fell gradually with the increase of pressure, 
excepting at the highest pressure ; with pebble a similar relation was indicated, though 
much less regularly ; with F. G. it was still less apparent, and with all three powders 
the proportion of this gas rose somewhat again at the highest pressure. With pebble 
and F. G. the hydrogen exhibited a steady diminution with increase of pressure, and a 
similar though less regular result was observable with R. L. G. It need be scarcely 
stated that the proportions of sulphuretted hydrogen and of hydrogen are in no instance 
sufficiently high to enter into account in a consideration of what are the chief reactions 
which occur upon the explosion of powder f. 
While the results, as regards gaseous products, furnished by the three gunpowders 
* Except in the case of the Spanish powder, which furnished an equally high proportion. — February 1875. 
f The additional analyses which we have made since this paper was presented to- the Eoyal Society enable 
us to summarize the general results furnished by examination of the gaseous products as follows : — (a) with 
all the powders the proportion of carbonic anhydride produced increases steadily and decidedly with the 
pressure; (5) with the P. and F. G. powders the carbonic oxide decreases steadily as the pressure increases; 
and the same is generally true as regards the E. L. G. powder, although the series of analyses exhibits some 
violent fluctuations ; (c) the proportions of sulphuretted hydrogen and of hydrogen furnished by all the powders 
fall somewhat as the pressures increase, though the diminution is not very decided or regular ; (cl) free oxygen 
was in no case found in the products from P. powder ; in one instance it was found in those from E. L. G., 
and it occurred in four instances in those from F. G. — February 1875. 
