29 2 SRfe Vitriol 



tk)n, is, that they not only difiblve in the grand na- 

 tural acid, but alfo in aqua-fortis, fpirit of fait and 

 vir<;gar, tho' indeed not with that intimacy of union 

 as happens in the former cafe, feeing verdigreafe, 

 which is prepared from copper and wine-vinegar, 

 or the like vegetable acid, and a vitriol, which 

 may be made from it with fpirit of fait, are by far 

 not to be compared to a copper-vitriol prepared 

 with fulphur. In fhort, under the appellation vi- 

 triol, when without any adjunct, fpecifying its metal, 

 we are never to underfland any other than a fort pre- 

 pared either from iron or copper, or both together. 



§. Of the production of vitriol from the pyrites. 

 This is the laft and moll important head of en- 

 quiry ; though indeed, it is not lb perplexing as 

 the external defcriptions from the names, figures, 

 and kinds of the vitriol were, feeing truth is con- 

 cife and intelligible, and writers having touched 

 but fparingly on this head, it is lefs confounded by 

 ambiguities and contradictions. We fhall for the 

 prefent drop the white pyrites, becaufe it is never 

 known to yield any vitriol ; and confine our re- 

 marks only to the yellowifh and yellow fort ; 

 which, together with their proper metal-earth alio, 

 pofTefs fulphur, by means of the acid fait, of 

 which, the vitriol, as a new production, ariles from 

 fuch earth. In the important bufinefs of vitri- 

 olifation, we are particularly to attend to the in- 

 ftruments or means ; and as thefe are two-fold, we 

 have a two- fold vitriolifation, or refolution of pyrites 

 to confider. The instruments are air and fire *, fome- 

 times the one, namely, the firft alone -, fometimes, 

 and that oftneft, both together •, at lead the fecond 

 is not generally fucctfsfu! without the firft. 



(1.) As to the air, it produces its effects both in 

 the grgove and at the day \ pyrites vitriolifing not 



only 



