362 On the Manufacture and 



In respect to the specific gravity of gunpowder, count Rum- 

 ford states, that '^ a cubic foot of water, holding 1000 ounces, 

 will hold 1077 ounces of fine grain powder, well beaten and 

 shaken together ; and that the real specific gravity of the solid 

 grains of gunpowder is as 1868 to 1000." 



I have, by repeated trials, found that the density of powder 

 varies considerably from various causes in manufacturing, for 

 which reason no exact table of the specific gravity can be 

 given ; but I must observe, that the above, as given by count 

 Rumford, is the greatest it will ever attain, in my opinion. I 

 have never seen any so much, and I have frequently seen it 

 less than that of water. 



In the foregoing account I have confined myself to a simple 

 relation of facts, from a consideration of which the following 

 observations are clearly deduced : 



1st, That the explosive force of gunpowder depends very 

 materially on the purity of the carbon employed. (Exper. 7.) 



2d, That the mixture only of the ingredients does not make 

 that thorough incorporation necessary for the proper combus- 

 tion and explosive effects of gunpowder. (Exper. 3, 4, 5, 6.) 

 3d, That the less moisture there is in gunpowder, the 

 stronger is its eiTect. This is clear, from gunpowder which 

 has attracted any degree of humidity being weaker than when 

 first made. 



I shall now beg to submit some ideas that occur to me from 

 a consideration of the whole of the circumstances I have re- 

 lated, and from what may be deduced from an examination 

 of the component parts of gunpowder. It appears to me that 

 no part of the explosive force consists in elastic vapour, formed, 

 ay the combustion, from water contained in it. So small a 

 portion of water is in the ingredients, and I have observed 

 that not any is gained in the manufacturing, that 1 cannot 

 conceive any water is carried off undecomposed, but that it 

 is converted into hydrogen and oxygen gases. Mr. Cruick- 

 shauk observes, ^' after the explosion of gunpowder over mer- 

 cury, no water is seen.*' I am of opinion that the explosive 

 force of gunpowder consists wholly in the several gases formed 

 by the combustion; and that, the quicker it takes fire, 

 the more gas 19 generated in a given time^ and its force con- 

 sequently 



