constituent Parts of Gunpowder. 363 



sequently greater. Lavoisier observes, its effect is increased 

 by the quantity of caloric disengaged at the moment of de- 

 flagration. 



It seems, therefore, that the combustion is carried on by 

 the oxygen supplied from the nitre ; that this gas is instantly 

 taken up by the sulphur and carbon ; and, converting those 

 substances into carbonic and sulphureous acid gases, azotic 

 gas being at the same time hberated from the nitre, the 

 water wliich may be in the nitre, and also that which is in 

 the charcoal, is decomposed ; and the oxygen taken up by the 

 carbon and sulphur, and the hydrogen set free. The force 

 arising from these gases, with the increased elasticity they re- 

 ceive from the increase of temperature caused by the combus- 

 tion, is surely sufficient to account for the effects we observe 

 in gunpowder. 



It may probably serve to elucidate the subject, if we con- 

 sider a little minutely what the component parts of gunpowder 

 are from chemical analysis. 



Nitre. 100 parts of nitre, according to Kirwan, consist of 

 Potash - - 51-8 -J 



Acid - - 44*0 Vdried in a heat of 70^' 



Water of composition 4*2 J 



By several experiments, I have found that nitre which had 

 been dried at 70*^ loses 3 per cent, in melting. 



Lavoisier says, 100 parts nitre consist of 



Potash 49, dry acid 5 1*0 ; and that this dry acid is, 

 Oxygen 49'6 

 Azot 10-4 



Charcoal, according to Lavoisier, absorbs 2*5714 of oxygen 

 in combustion. From several experiments which I have 

 made, I have reason to conclude, that charcoal, when used, 

 contains about l-8th part of water, which it has absorbed. 



Sulphur, according to Berthollet, requires for every 160 

 parts 36*8 of oxygen to form sulphuric acid; of course, a 

 smaller quantity of oxygen would be necessary for their con- 

 version into sulphureous acid gas : I shall take this at 30 per 

 cent,y which is probably not far from the truth, and, at any 

 rate, near enough for our present purpose. No experiment, 

 that I know of, has been made to ascertain this point. 



Z z ? Admitting 



