VEINSTONES. 557 



crystals, which, when enlightened by torches, ex- 

 ceed all the ideas of oriental magnificence, and 

 seem the chosen abodes of the fairies of the n>ine; 

 a race whose existence was anciently credited in 

 all mineral countries. 



These cavities are often found where the vein is 

 most powerful, and the sides are covered with de- 

 positions of various periods, whence Werner ad- 

 duces them in support of his theory, that the veins 

 were once empty, and were filled from above ; 

 especially as the crystals are covered on that side 

 with little crystals of pyrites, magnetic iron, and 

 galena, which, by his doctrine, may have distilled 

 from above. This is opposed by the theory of 

 Trebra, who for thirty years superintended the Trebra'sidea* 

 mines of the Hartz, and who affirms that metallic 

 veins are formed by the fermentation and exalta- 

 tion of vapours, which we now call gases ; and 

 which operate as it were a kind of life in the inte- 

 rior of the earth, perpetually decomposing and 

 transmuting mineral substances*. He would per- 

 haps have inferred that, though the gases rose 

 from beneath, they were congealed, as in distil- 

 lery, by the superior cold, and then let fall their 

 depositions. Veins sometimes cross each other in- 

 different directions ; and it seems clear that those' 



* See his curious work on the Interior of Mountains, a folio 

 volume translated into French, by Dietrich. 



