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experiment, two, three, or more grains of Gunpowder were put 

 into the glals, the eliarcoal and fulphur were dirperlbd more for- 

 cibly than when a linglc grain was ufed ; and I coidd plainly dif- 

 tinguifli the particles of the fulphur from thofe of the faltpetre, for 

 in fome places they lay fo thick together as to exhibit a yellow 

 colour. The A\hite fmoke (as it appeared to (he eye) was in fad; 

 the faltpetre. This I immediately brought before the view of a 

 good microfcope, and faw with great pleafure th^ inconceivable 

 number of its component particles, of an incredible minutenefs, in 

 a kind of circular motion, one among another ; and, to my moll 

 accurate infpeclion, they all appeared of a perfed: round figure, 

 belides feveral others which adhered to the glafs : after a Ihort 

 time, obferving that thefe moving particles began gradually to fub- 

 Cde, I placed the glafs not in an upright polition, but on its fide, 

 that they might not fink to the bottom among the particles of 

 charcoal and fulphur. When the glafs had remained in this pofi- 

 tion fo long that I judged all the faltpetre particles were in a Itate 

 of refi, I again examined them, and law with great furprize, that 

 almoll all thefe particles which a little time before appeared glo- 

 bular, or to which I could not affign any other figure than that of 

 globules, were now converted into hexagons, or falts of fix fides, 

 fome of which were very exa6lly lliaped, others more irregular 

 hexagons ; and many of them, I could plainly difcern, rifing in a 

 kind of piramidical Ihape, like a pointed diamond. AMien I ex- 

 amined thofe parts of the glafs where tlie particles of faltpetre lay 

 in confiderable numbers together, I could difcover but few of them 

 to be of an hexagonal Ihape, by reafon that the points of the par- 

 ticles (at the time they changed from globular to hexagonal figures) 

 touching each other, they thick fo clofely together as to exhibit, 

 upon the whole, only irregular figures. In another glafs I faw 

 (among the figures before defcribed) fome of the particles of the falt- 

 petre very long and thin, fome of which had the refemblance of 



