122 M.BnocuAJin on ike 



which being, in the greater number of chains, the base of all 

 the other rocks, formed until now the most plausible cha- 

 racter of their primordial formation. 



Let us guard ourselves however from pronouncing in too 

 decided a manner on the absence of true granite in the Alps, 

 even in that part of the chain between the Mont Cenis and 

 St. Gothard," the only one that I have visited. 



I have observed true formations of granite in the Alps, 

 and their existence appears to me to give a new presumption 

 against those of Mont Blanc and other summits of the centre. 

 In fact, it must not be looked for in these high crests ; at 

 least all the granitic rocks that I have there met with ap- 

 proached more or less to those of Mont Blanc (with only 

 some exceptions on which we cannot yet decide) ; it is in 

 the low mountains which form as it were the advanced posts 

 of the Alps on the side of Piedmont, from Yvree and even 

 from Turin to the Lago Maggiore. Among the granitic rocks 

 I have observed, there is not one that is analogous to those 

 of Mont Blanc ; there are many whose true place I shall not 

 venture to assign ; but between Biella and Crevacore, near 

 la Sesia, I have met with a true granite formation having all 

 the characters seen in that of the Limousin, Forez, and other 

 chains. The rocks are never schistose there ; the mica is 

 well defined, and does not at all partake of the characters 

 of talc ; the quartz is uniformly disseminated ; the felspar 

 is often earthy ; and the union of these elements constitutes 

 granites, often soft and friable like those of the Limousin. 

 For many leagues I only found half decomposed granites. 

 Lastly, kaolin is there met with, which I do not believe has 

 ever been noticed in any part of the central mountains of the 

 chain, and which appears very generally to belong to granite 

 formations and others that approach them. 



I shall add that the form even of these mountains is pre- 

 cisely that admitted as most common in the granite forma- 

 tions ; i. e. few escarpments, summits rounded, and as it were 

 in the form of paps ; valleys extremely contorted, &c. 



There are also, in the neighbourhood, solid granites. The 

 famous rock of Baveno, which has aiforded the beautiful 



