from /fe Pyrites, 315 



like a fand only, while urged by a brifk boiling ; 

 though from thefe fmaller cryftals reducible to 

 larger lumps. 



On the head of the origination of white vitriol* 

 I cannot omit mentioning a query put to me by 

 an ingenious friend, namely, Whether zink* or 

 rather, zinky fubftances, mould here be entirely 

 difregarded ? This at leaft is true, that this fur- 

 ng body principally ihews itfelf at the Ram- 

 melfberg, nay, is no ftranger with us at Friberg, 

 under another form indeed ; though the greateft 

 artift will find it difficult enough to hit on a me- 

 thod c: properly combining it in its feparated ftate 

 with the fulphur-acid, into fuch a white vitriol. 



Under the head of vitriol from pyrites* we mufl 

 obferve the difference of elixations, namely, that 

 many 0; them, having flood for fome weeks, turn 

 mouldy, as happened to myfelf once from the mixt- 

 wprk of the Rothe-grube; and again, if I miftake 

 not, from the terra martis Hajfiaca. Now pyrites* 

 as luch, exhibits no fuch appearance, but the ad- 

 joining interfperfed minerals, and indeed the mi* 

 very, loamy, black fatty fort may, though not 

 all, yet a certain fort of them ; fuch in general are 

 thofe that yield alum •, and all of a fatty, bitumi- 

 nous, inflammable nature, or of a muddy origina- 

 tion : though I propofe this only as a query, and 

 not as a certain undoubted truth. ' 



There is alfo incidentally, from the procefs of 

 vitriolifation* alum procured; not from the pyrites 

 in its proper mixtion, .but from the bituminous 

 matter adhering to the pyrites* when its acid chances 

 to lay hold on the metal-earth, it may not, at the 

 re untouched the black, fatty, ad- 

 joining 



