196 DOMAIN X. TRANSILIENT. 



" The fourth is a grey granite, with very small 

 grains of quartz, felspar, and mica. 



" This transition in general occupies an in- 

 considerable thickness; in some places these 

 four layers, taken together, are not more than a 

 foot: nevertheless, the granite does not acquire 

 all its perfection, its grains are not very exact 

 and distinct, till a distance of some feet from its 

 junction. Layers are observed in this perfect 

 granite; they are parallel to all those which 

 form this transition. 



" Following it round the mountain, I traced 

 this junction of schisti to a considerable distance, 

 by sounding every where with a hammer the 

 bordering beds : I observed no particular differ- 

 ence in the nature of the layers, which form 

 the transition between granite and schistus ; but 

 I found some alteration in the position of the 

 beds : advancing towards the S. W. I observed 

 schisti as well as granites overhanging towards 

 the valley, here of 35, there even of 47 degrees, 

 The direction of the layers also changes a little. 

 Those nearest to Col Ferret run to the S. S. W., 

 while those most distant from this same Col, run 

 about 30 degrees more to the west. 



" I observed also, in some places, vitriolic 

 effervescences which distilled, sometimes from 

 the schistus, sometimes from the granite itself.'* 





