60 The Production and Generation 



warning trough. And as the univerfal, crude 

 earth, not as in the groove, but as at the day, 

 feldom amounts to any confiderable gold or filver 

 yield-, iron, on the contrary, is every where to be 

 found in mar], clay and loam, being very tender 

 bodies, and confequently the bed adapted for 

 metallifation ; and in all underturf, or garden earth 

 Infallibly, and that in confiderable quantities. 



'Tis alfo true, that we muft not deny crude earth 

 fometimes to yield copper, lead and tin -, yet more 

 rarely than it does iron. Befides, the tin, that 

 might be collected from the upper crude earth- 

 layers, is not from that earth as fuch, but from 

 the tin- Hone, and Jhoads and grains mixed therein, 

 and thus educed, as from ftream works. But ac- 

 cording to Tollius's and Barba's opinion, it fhould 

 be an earth, not only holding, but' alfo generating 

 tin : as the former obferved not far from Joachim- 

 flhal near Gottefgabe on the confines of Bohemia; 

 and the latter, at Potofi* •, tho' inftances of this 

 fort are extremely rare. Of copper I have no fuch 

 examples, if we except the coppery gurs or juices 

 in mines, as arifing from nothing elfe but difTolved, 

 crumbled, vitriol efcent copper-pyrites, and preci- 

 pitated copper-ochres or ruft, alfo aeruginous clays 

 or marls, which have their colour from difTolved 

 copper. And that extremely beautiful fmeary 

 Sifkin-green, to be met with near Tfchopau, de- 

 ferves a peculiar examination. 



As to lead, befides the native grains from 



Maflaw in Silefia, I have had no other inftance, 



befides what the very leady clays of the Rauten- 



crantz at Johan-Georgen-ftadt, there called lead- 



fpat, afford, and what fometimes breaks here at 



Friberg, 



* Tollii Epift. itiner. pag. 96. Barbae Bergbucklein, 

 pag. 114. 



