of the P Y R I T E s. 69 



But we need not go fo far for inftances ; feeing 

 in the tin-ftream-works of Friberg, the tin-Jhoads 

 are often intermixed with pyrites, as fmelters find 

 to their coil. Should we allow the 'pyrites, from 

 its fuppofed univerfality, to manifeft itfelf in many 

 places as z/hoad-, yet it muft alio be allowed, that 

 this mineral, above all others, is moil fufceptible 

 of deftruction, and of becoming an earth again ; 

 efpecially if lying near the day, and thereby more 

 expofed to the action of the air ; fo that in the 

 courfe of fome thoufand years, many teftimonies 

 of the deluge may be quite effaced. Further, 

 that this furmife is not without foundation, may 

 be concluded from the rufty fpots and nefts found 

 in many places ; in particular, thofe in fand ftone, 

 fhew remains and tokens of weathered, ordeftroyed 

 pyrites. Nor are we to wonder, that copper pyrites is 

 more commonly to be met with than iron-pyrites ; 

 feeing the former is generally more durable and 

 lading, if not fometimes indeftructible. 



Again, it will be no difficult matter to form a 

 judgement, and fhew the weaknefs and ineffi- 

 ciency of the remarks generally made on Jhoads. 

 Thus much commonly holds true, that, the 

 ponderous and mod metallic fort cannot eafi* 

 ly remain near the furface, but muft fink down. 

 Concerning pieces of ore which happen to be 

 fmooth or (harp, we may probably conjecture, 

 whether the vein, whence they came, was at 

 hand, or at a diftance : if the ftone thereof, or 

 of the adjoining mountain, be the fame with that 

 of the Jhoad, we may imagine the vein to lie there, 

 and there we may work for it; and Jhoads in high 

 mountains, and on eafy declivities, are more ea- 

 fily come at. But every one fees how fallacious 

 fuch indications or directions are -, for fuch broken 

 fragments may, in a tender bottom, be driven to 



F 3 a fuf- 



