COMPOSITION AND ANALYSIS OF GUNPOWDER. 183 



far as I have tried them, in the quantity of the saltpetre they con. 

 lain. From some sorts of powder, I hare got after the rate of 

 7615. of saltpetre, from lOOlb. of the gunpowder. 



The method of analysing gunpowder, by evaporating the sulphur, 

 is not wholly to be relied upon ; I have often observed, that when 

 mixtures of sulphur and charcoal have been exposed to evapora- 

 tion, on a plate of heated copper, the remainder has weighed loss 

 than the charcoal which entered the composition, part of it having 

 been carried off by the violent evaporation of the sulphur: and hence 

 the proportion of sulphur in the above analysis is probably too great. 

 I am aware that this observation is wholly opposite to the conclusion 

 of M. Beaume, who contends, that one twenty. fourth part of the 

 weight of the sulphur employed in any mixture of sulphur and 

 charcoal, adheres so strongly to the charcoal, that it cannot be se. 

 parated from it without burning the charcoal. I can only say, 

 that he separated the sulphur by burning it, and 1 separated mine 

 by subliming it without suffering it to take fire, and this difference 

 in the manner of making the experiment, may perhaps be sufficient 

 to account for the different results. But it is unnecessary to pursue 

 this subject further ; there are several things to be attended to in. 

 forming a complete analysis of gunpowder, which any person tole- 

 rably well versed in chemistry, would certainly take notice of, if 

 the analysis of any particular powder was required to be made, 

 and which cannot, in this general view, be minutely described : 

 and, indeed, it is the less necessary to enter into a detail on this 

 subject, as the strength of the powder is not so much affected by 

 small variations in the quantities of the sulphur and charcoal, which 

 enter into its composition ; and the method of ascertaining the 

 quantity and quality of the saltpetre, in any particular gunpowder, 

 has been sufficiently explained. 



la order to judge with more certainty concerning the effect of 

 sea.salt, when mixed with saltpetre in attracting the humidity of 

 the air, I made the following experiment. Five parts of pure salt- 

 petre in powder, were exposed for a month to a moist atmosphere, 

 but I did not observe that the saltpetre hod gained the least increase 

 of weight ; for the same length of time, and in the same place, I 

 exposed four parts of saltpetre mixed with one of common salt, 

 and this mixture had attracted so much moisture, that it was in a 

 state of fluidity. 



[Bishop JValson. 

 N4 



