84 Experiments 7tpon Giinpowder. 



of powder was better adapted for particular purposes 

 than another, or from experiments made on purpose to 

 ascertain the fact ? There is one circumstance that 

 would lead us to suppose that that was the case. That 

 kind of powder which was designed for great guns and 

 mortars was weaker than those which were intended to 

 be used in smaller pieces; for if there is any foundation 

 for these conjectures, it is certain that the weakest pow- 

 der, or the heaviest in proportion to its elastic force, 

 ought to be used to impel the heaviest bullets, and par- 

 ticularly in guns that are imperfectly formed, where the 

 vent is large and the windage very great. 



I ami perfectly aware that an objection may here be 

 made, viz. that the elastic fluid which is generated from 

 gunpowder must be supposed to have the same proper- 

 ties very nearly, whatever may be the proportion of the 

 several ingredients, and that therefore the only difference 

 there can be in powder is, that one kind may generate 

 more of this fluid and another less ; and that when it 

 is generated, it acts in the same manner, and will alike 

 escape, and with the same velocity, by any passage it can 

 find. But to this I answer, though the fluid may be the 

 same, as undoubtedly it is, and though its density and 

 elasticity may be the same in all cases, at the instant of 

 its generation, yet, in the explosion, the elastic and un- 

 elastic parts are so mixed and blended, that I imagine 

 the fluid cannot expand without taking the gross matter 

 along with it, and the velocity with which the flame is- 

 sues out at the vent is to be computed from the elas- 

 ticity of the fluid and the density or v/eight of the fluid 

 and the gross matter taken together, and not simply 

 from the elasticity and density of the fluid. If antimo- 

 ny in an impalpable powder, or any other heavy body. 



