( lOd ) 



parts ; but now we fee the contrary to be the fad:, for the particles 

 of air in a clofed giafs, wherein Gunpowder is fired, are fo com- 

 prefled together, that feven parts out of eight will efcape out of the 

 glafs upon its being opened. 



I have endeavoured to fatisfy myfelf upon this fubjc(5t, by faying 

 that the particles of air in their natural Itate in the glafs, before 

 the firing of the Gunpowder, were, upon fuch firing, divided into 

 llill finaller particles, and that thole fmaller particles being of a glo- 

 bular figure, mull: (lb long as they remain dillind: and not forced 

 one into another) touch each other on their fuperficies, and leave 

 between them in the remaining fpaces, fome more thin and fubtile 

 fubllance ; whence it mull follow, that the particles of air within 

 the glafs, will require a greater fpace than they occupied before ; 

 but on the other hand, I confidered, that though every particle of 

 air which was in the glafs before the firing of the Gunpowder 

 might, upon the firing it, be divided into a thoufand fmaller parts, 

 this would not produce fo great an expanfion as w^e experience ; 

 for, let a fack of wheat be ground into fine flour, every grain will 

 be divided into a thoufand parts at leaft, and though the wheat is 

 divided into many fmall particles, it will not occupy feven or eight 

 times greater fpace than it did before the grinding. In fliort, with 

 all my obfervations refpefting the great expanfion or explofion of 

 Gunpowder when it is fired, I have not been able to explain the 

 matter to my own fatisfaclion.* 



* Mr. Leeuwenhock,. in this Eflay, attributes the force of Gunpowder, when exploded, to 

 fome alteration produced by it in the circumambient air, rather than (o the produrtion or 

 generation of air from the G unjjowder itfell' ; and though in fjmo few places he exprcfles hlm- 

 felfin a manner, intimating, that air is generated by Gunpowder when fired, he does not 

 feem to have been fully informed of the do(5lriiie now tftablifliod, namely, that Gunpowder, 

 or rather its principal romponent, Saltpelrc, contains in it a great quantity of air cond-.'nfod 

 as much as pofTiblc, which, when fct at libcrly, upon the firing the Gunpowder, doL'.«, by its 

 elafticity or expanfive power, produce the violent and fiirprifing efl'ffls we obfervc. JVlr, 

 Leeuwenhock's experiments do, however, confirm that dodtriue, and they arc themfelvtsilluf>r 

 trated by it. 



