DOMAIN Til. COMPOSITE. 



ning recess; and which show the tendency, 

 common in this sort of stone, to divide itself into 

 fragments of even sides. 



" Above and beneath this vein there are others 

 more narrow, one in particular, which is not 

 above half an inch in breadth, and is prolonged, 

 like the former, for a space of seven or eight 

 feet. Some of the little veins show that the 

 beds of the roche de corne have subsided, or sunk 

 unequally, since the granite penetrated into it; 

 for they seem to be suddenly interrupted, and to 

 begin anew a little higher or a little lower. The 

 broadest vein seems also to have yielded a little 

 in some parts. 



" These veins of granite, which were then 

 new to me, appear to throw light on the forma- 

 tion of that stone. For to any man a little 

 versed in mineralogy, it is almost demonstrable 

 that this granite has been formed in these veins, 

 by mere filtration of the waters, which, in de- 

 scending from the mountain of granite, which 

 hangs over these schistose rocks, brought down 

 the elements of that mountain, which they de- 

 posited and crystallised in these fissures. When 

 one finds the slits of a marble, or of a slate, filled 

 with spar or quartz, one decides, without hesi- 

 tation, that these foreign bodies, or parasitical, 

 as Linnaeus calls them, have been brought by 



