358 The Bifiory of 



to lofe the brandy paffing over •, which even 

 then, without railing any degree of warmth 

 in the pyrites, began moftly in the night time to 

 re-diftil over, though flowly, there being, for 

 weeks together, not above half a pint procured : 

 this brandy tafted fomething of the pyrites, and 

 was very phlegmatic •, whence I conjecture, not 

 only the bare nocturnal cold, but alfo the inteftine 

 heat of the -pyrites to have contributed fomething 

 to its paffing over. Be this as it will, thus much at 

 leaft we may learn from the refolution and vitrio- 

 lifation of the fulphur- pyrites, that in it is certainly 

 included fomething highly prone to inteftine mo- 

 tion •, and to be fought for either in the common 

 fulphur or the iron ; of both which we know the 

 pyrites confifts. The phasnomina arifing from arti- 

 ficial and natural productions, combined with ful- 

 phur ; for inftance, phofphorus and the bitumi- 

 nous alum ores, which take fire in the open air, and 

 refolve to alum, mould almoft perfuade one, that 

 the fulphur ought to be confidered as the principal 

 caufe of the vitriolefcence of pyrites : and accord- 

 ingly I underftand the matter thus ; the inflam- 

 mable fubftance combined with the fulphur of the 

 pyrites, is itfelf by the accefs of the external moift 

 air, not only firft excited, and then the whole 

 concrete put into motion by it, but moreover is 

 itill more and more freed, and at length quite 

 feparated from its union with the acid ; confe- 

 quently, fuch acid, after a perfect ieparation, 

 unites with the iron, and forms a vitriol. By way 

 of conclufion, I add that no one, fo far as I know, 

 has hitherto written of the vitriol pyrites of Al- 

 merode, nor are there any vitriol- huts there. 

 3 Xis true, the alum-boilers prepare from their lie, 

 precipitated by means of urine, a green vitriol, 



but 



