from the Pyrites. s&g 



for the moil part coppery, whence it is ufed as aa 

 emetic, and called vomitoria •, I fhall not aflert - 

 that its contents are alio fomewhat aluminous, 

 having not examined it thoroughly, though I havf 



often iuipected it. 



That the vitriol-earth is metallic, and this al- 

 ways without exception, its metallifation clearly 

 fhcws, as being performable by addition of in- 

 flammable, fatty things, nay, often happening 

 fpontaneoudy -, when, for inftance, the retorts, in 

 the courfe of the ditlillation of vitriol, happen to 

 have cracks, through which the fatty, fiery par- 

 ticles mix with the earth, which is in the higheff 

 glow, and thus fitted or appropriated, actually re- 

 fund a degree of metalleity, and form an iron, as 

 once happened to myfelf from a certain vitriol ; 

 the iron not only appearing by the magnet, but to 

 be (hewn corporally. 



The proportion of thefe two parts in vitriol is 

 generally the fame in all, namely, in a pound of 

 a freih uncrumbled vitriol, commonly from ten to 

 twelve loths, and thus full a third of metallic 

 earth ; four loths, or about an eighth of acid fair, 

 or highly rectified oil of vitriol, including what is 

 collected from the gentle evaporation of the fpirit, 

 and from fixteen to eighteen, that is, a compleat 

 half water, or phlegm, not omitting what is wafted 

 by the foregoing open calcination, or rather dry- 

 ing, in the air. 



The reafon of their inconstancy in the yield of 

 metallic earth, is to be afcribed either to the dif- 

 ference of, or admixtures in, the vitriols, or to the 

 evaporation and coction of the vitriols themfelves $ 

 £nce wiany vitriols poiTefs a copper and iron earth 



T z at: 



