24 DISCOXIRSK ON THE REVOLUTION'S OF 



the hardest stones often incrust them, and are everywhere penetrated 

 by them. Every part of the world, both hemispheres, all the con- 

 tinents, all the islands of any extent, afford the same phenomenon. 

 The time is past when ignorance could assert that these relics of 

 organic bodies were but freaks of Nature, productions engendered in 

 the bosom of the earth by its inmate creative power ; and the efforts 

 of metaphysicians will not suffice to establish such assertions. A 

 minute investigation of the formation of these deposits, of their con- 

 texture, and even of their chemical composition, does not detect the least 

 difference between the fossil shells and those produced from the sea. 

 Their conformation is not less perfect. We do not observe either the 

 marks of friction or fracture, evincing violent removal. The smallest 

 of them preserve their most delicate parts, their finest points, their 

 most minute indications. Thus they have not only lived in the sea, but 

 have been deposited by the sea. The sea has left them in the places 

 where they are found ; but the sea has for a time remained in these 

 places, it has remained there sufficiently long and undisturbedly to be 

 enabled to form those deposites, so regular, so thick, so extensive, and 

 so solid, which compose these layers of aquatic animals. The basis 

 of the sea has then experienced a change either in extent or situation. 

 What a result from the first examination and the most superficial 

 observation ! 



The traces of revolution become more striking when we ascend 

 higher, when we approach closer to the foot of the great chains of 

 mountains. 



There are also banks of shells. Their thickness and solidity are 

 remarkable. The shells are equally numerous, equally well pre- 

 served, but they are not the same species. The layers which contain 

 them are no longer generally horizontal ; they lie obliquely, sometimes 

 nearly perpendicular. Instead of digging deeply, as in the plains and 

 broad hills, to ascertain the order of the banks, we here have them 

 side -ways in following the valleys formed by the convulsions which 

 have rent them asunder. Immense masses of their remains constitute 

 at the foot of their pinnacles heavy mounds, the height of which is 

 increased by every thaw and every storm. 



And these upright (redresses) banks, which form the crests of the 

 secondary mountains, are not placed on the horizontal banks of the 

 hills which form their lower ascents ; on the contrary, they are sunk 

 beneath them. These hills rest on their declivities. When the 

 horizontal layers in the vicinity of these mountains with oblique strata 

 are laid open, we again find the layers oblique in the excavation; 

 sometimes even when the oblique layers are not very much elevated, 



