234 biographical Memoir of Horace Benedict de Saussure. 



mitive deposites, which preceding observations had long before 

 established, were now invincibly confirmed. 



Thus, every step that he advanced among the mountains dis- 

 covered to him some new truth, and either enabled him better 

 to arrange the series of those he already possessed, or to fill up 

 some void in it. It would be interesting to trace all the meta- 

 morphoses which the system of his ideas had undergone ; but 

 time does not permit. Let us content ourselves with drawing a 

 brief sketch of the principal acquisitions to the theory of the 

 earth, which result from a concluding analysis of his works. He 

 destroyed the* idea, which had been very prevalent until his 

 time, of a central fire, a source of heat situated in the interior of' 

 the earth. His experiments even prove that the water of the 

 sea and of lakes is colder in proportion to the depth from which 

 it is taken. He proved that granite was the oldest primitive rock, 

 and that which serves as a basis to all the others ; he shewed 

 that it was disposed in strata, and formed by crystallization in 

 a fluid, and that if its strata are at the present day almost all 

 vertical, this position is owing to a posterior revolution. He 

 proved that the strata of the lateral mountains are always in- 

 clined toward the central chain, namely, the granite chain ; and 

 that they present their precipices to this chain, as if they had 

 been broken upon it. He ascertained that the mountains are 

 the more rugged, and their strata depart the more from their 

 horizontal line, in proportion to the antiquity of their formation. 

 He shewed, that, between the mountains of different orders, 

 there are always heaps of fragments, rolled stones, and all the 

 other indications of violent convulsions. Lastly, he pointed out 

 the admirable contrivance, which supplies and renews among the 

 snows of the high mountains, the reservoirs necessary for the 

 production of large rivers. 



Had he -only bestowed a little more attention on petrifactions, 

 and their positions, it might have been said, that we owed to 

 him all the foundations on which geology has hitherto been 

 built ; but, incessantly occupied with the great primitive chains, 

 and the terrible catastrophes that must have taken place to have 

 overturned their enormous masses, it would appear that he had 

 formed a somewhat erroneous idea of those lesser mountains or 

 hills whose repose had not been disturbed, and which contain 

 remains of the newest epochs of the history of the globe. 



