233 



stead of millions of years being required to complete 

 the destruction of these mountains, according to the 

 calculation of Gensanne, or to level them with the val- 

 lies, it would require as many million of millions, up- 

 on a moderate calculation. 



The few preceding remarks are intended to apply, 

 more immediately, to the opinions advanced by Pallas- 

 sau and Gensanne, relative to the disintegration of 

 rocks, and gradual depression of the Pyrennees, but 

 which, however, I considered equally applicable to 

 every other chain of mountains, and the rocks of which 

 they are composed, that can be found upon the surface 

 of the globe. 



Where I to assume the instances in which rocks of 

 various kinds, and such as are most prevalent, have 

 been employed in the arts, from the most remote pe- 

 riods of time, to prove the non- decomposition of those 

 materials, and which, by the by, having experienced 

 no change in composition or structure, by being remov- 

 ed from their primitive situation, or from having re- 

 ceived new forms by the hand of the artist, are cases as 

 decidedly in point, and are as suitable criteria, on which 

 to form an opinion on this subject, as if they still lay 

 exposed on the mountains. Were I permitted to re- 

 sort to the ruins of ancient cities, for monuments and 

 monumental inscriptions, that have for ages resisted 

 the agents of decomposition, and with which to com- 

 bat the advocates for the disintegration of rocks, and 

 the degradation of mountains, proofs the most palpable 

 and convincing could be adduced to establish the facl, 



