SUPPLEMENT. 



Trebra had before stated a fact more applicable to 

 the present subject, and observed by himself in the 

 mine called Dreyweiber, in the district of Marien- 

 berg. In 1777, on enlarging and opening that 

 mine, which had been under water for two hun- 

 dred years, four standard posts were found, form- 

 ing part of the fabric of an ancient pit. The 

 lower ends of these posts were buried in a new 

 vein, consisting of barytes, of a flesh colour, and 

 of green fluor. Moreover, the extremities of these 

 pieces of wood were covered with a black and 

 brown ferruginous matter, containing much vitre- 

 ous silver ore, and native silver in extremely thin 

 leaves*. From these and other examples, it may 

 be inferred that substances, reputed the most 

 primeval, are in fact daily produced by nature ; 

 and that the same Power which has impressed 

 such wonderful and perpetual motion on the pla- 

 netary bodies, also animates, so to speak, their 

 interior ; where to suppose absolute death and in- 

 ertion, would be to contradict all the other pheno- 

 mena. 



Age of vein- According to Werner, the most ancient veins 



stones. p res ent felspar, schorl, topaz, and beryl. Those 



which yield grey and green mica, are also very 



ancient ; while the calcareous stones appear more 



* Jour, des Mines, Y. 721. 



