MODE VI. SERPENTINE. 



in distinct beds, but which alternate, and are 

 reciprocally overlaid, the one on the other. 



" Serpentine is rather more abundant in na- 

 ture than traps and corniennes ; and much more 

 so than porphyries. 



u It is generally found in amorphous masses, 

 like porphyries, and seldom in distinct beds. 

 It forms chains of hills or mountains, but little 

 elevated, at the foot of great granitic chains : it 

 is very rare to find it in very lofty mountains, 

 and still more rare to see it form beds (arrects) 

 approaching a vertical position, a position so 

 common to micaceous schisti. 



cc In regard to the little elevation at which 

 serpentine is generally found, there is an excep- 

 tion, perhaps unique and very remarkable, in 

 Mount Rosa, where there are summits which Mount Rosa. 

 surround the central part of that mountain, 

 which are composed of serpentine, although 

 their elevation is from 100 to 1700 fathoms, and 

 upwards ; and what is also very remarkable, is, 

 that the beds of this rock are there in a position 

 most often horizontal. But even this position, 

 and the presence of serpentine at this great ele- 

 vation, are owing to the same cause, which I 

 shall explain in treating of geology ; for this 

 mountain, become famous since the travels of 

 Saussure to that region, and which is one of the 



VOL. i. z 



