C 154 ) 



figure ; yet I doiibted not they were all of the fame fliape with the 

 former : and I was confirmed in this my opinion, by obferving now 

 and then a larger particle among them, which was of the fame 

 fliape I have mentioned. The number of thefe faltpetre particles 

 produced from one grain of Gunpowder was fo inconceivably great 

 that I dare not make a computation of them, they were more in 

 number than the particles of fulphur and charcoal ; and when I 

 figured in my imagination any given particle, the fize of a grain of 

 fand, to be divided into a thoufand millions of parts, I concluded 

 in my mind, that the particles of faltpetre, fulphur, and charcoal 

 contained within a grain of Gunpowder, were much more nu- 

 merous. Thefe obfervations were made with the greatefl diftind;- 

 nefs when I ufed only one grain of Gunpowder ; for when three 

 grains were fired together, the faltpetre blew up with it the fulphur 

 and charcoal, the particles of which not only rendered the view 

 indillinct, but alio impeded the change of the globular figures into 

 hexagons. 



I have alfo taken notice, that if a grain of Gunpowder is fired 

 at the bottom as it lies, then the fulphur and charcoal it contains 

 •are blown up on high ; but if it is fired at the top, then but little 

 of the charcoal, and ftill lefs of the fulphur, are driven upwards. 



Thefe obfenations caufed me to reflect on the manner in which 

 Gunpowder is proved amongll us, to judge whether it be of a 

 good quality : this is peformed by taking the quantity of a mulket 

 charge of Gunpowder, and placing it in as clofe an heap, of a 

 conical ihape, as may be, on clean white paper, and then giving 

 fire to it with a burning match; and if, in this operation, the 

 paper is neither burnt nor blackened, the Giinpowder is eftecmed 

 to be good. Neverthelefs, I cannot but think that much of this 

 depends upon the perfon who gives the fire ; for if the point of the 

 burning match is applied to the upper furface of the Gunpowder, 

 the conf.qucnce mull be, that the paper will be very much black- 

 ened, and alfo burnt, by reafon that the upper part of the Gun- 



