of the Pyrites. 265 



pour, yet to the water, ruaning over it. Again, it 

 fnews, that in cal carious hot-fprings, it may be 

 burnt by fubterraneous fires even in the bowels of 

 the earth, and thus communicate itfelf not only to 

 the intercurrent waters, but probably, as in flack- 

 ing quick-lime, may emit a faline, earthy fume, 

 fitted here and there, efpecially with the acid of 

 other vapours, for all manner of mineral produc- 

 tions. 



Pyrites is, preferably to all other forts, capable of 

 manifefting tne fubterraneous weathering of ores -, 

 yet the white, or poifon pyrites is incapable of any 

 fuch figns in the bowels of the earth, or by any ex- 

 periments in the huts, like what we obferve of the 

 yellowilh and yellow. The coppery fort, it is true, 

 will not eafiiy fume or exhale at the day, unlefs it 

 be made very fmall, and lie expofed in large heaps 

 in a proper place to weather and fun. But the cop- 

 pery waters in the grooves, having their original 

 only from refolved pyrites, fhew alfo that copper- 

 pyrites, efpecially in the bowels of the earth, and 

 under certain circumftances, is liable to deftruc- 

 tion or refolurion, 



Thefe waters, which are commonly called ce- 

 ment -waters^ are not only obferved at Neufol in 

 Hungary, but alfo in many grooves with us at Fri- 

 berg : and it would feem to me, that the more 

 coppery the pyrites are, in which cafe we at Friberg 

 ufually call them copper -ores, not pyrites, the lefs 

 yielding they are to fuch weatherings^ and the fir- 

 mer and more conftant they remain \ whereas the 

 lefs copper the pyrites happens to hold, and the 

 purer they are in iron, it more eafiiy vitriolifes ; 

 befides, that we have fewer inftances of fuch vitrio- 

 lic waters, but many of fprings, holding pure 



iron- 



