G E O L O G Y. 



CHAP. I. 



On the general Objects of Geological Science. 



THE slightest examination of the surface of the Earth 

 displays to us numerous irregularities hy which its 

 spherical form is modified ; and, when we penetrate 

 within it, we discover that it contains many rocks of 

 different characters, disposed in a confused manner, 

 and giving rise to the inequalities which form its moun- 

 tains and its valleys, which are the immediate causes 

 of the elevation of its continents and the depression of 

 its seas. The study and description of these substances 

 and these appearances, constitute the natural history 

 of the Earth, according to the simplest view of that 

 science. Thus this branch of Natural History com- 

 prises those circumstances in the disposition of the 

 surface, which do not appertain to geography ; toge- 

 ther with the distribution, the mutual relations, and 

 the nature, of all the substances which enter into its 

 composition. These again subdivide themselves into 



VOL. I. B 



