92 GEOLOGY. 



the handle of which, with the board was petrified, but 

 the hammer being of iron, retained its natural state. 



These are a few instances, among thousands, which 

 might be mentioned, to prove that the changes our earth 

 has undergone, have been gradual and constant, and that 

 minerals, rocks and soils, and even mountains have been 

 formed since the creation both of the vegetable and 

 animal kingdoms commenced, and even after man was 

 formed, and had made some advances in the arts of 

 civilization. Indeed no one can doubt for a moment, 

 who has paid the least attention to the subject, that our 

 globe has been subject to constant and important 

 changes from the time that the materials of which it is 

 composed were formed out of nothing, until the present 

 moment. And these changes which come within our 

 knowledge are so great, as to afford strong evidence 

 that the earth could not have existed for a much longer 

 period than that assigned by Moses. 



AGES OF ROCKS. 



From views and facts already presented, it must be 

 concluded that rocks and mountains have different ages. 

 Some have existed for six thousand years, while others 

 are at this moment in a process of formation. And there 

 is good reason to believe, that every moment during the 

 whole of this period, these formations have been going on. 



We not only know that rocks have different ages, but 

 we know which are oldest. All geologists unite in the 

 opinion, that granite was the first solid substance formed 

 from the great chaotic ocean ; and that the coarsest 

 masses of this rock are older than those of a finer 

 texture. 



Next in age to granite, is gneiss, consisting of the 

 same ingredients, but of a finer texture and a more 

 slaty character. 



Mica slate is considered by most geologists as the 

 third rock in age. 



Lime has be^n forming in all ages of the world. 

 Some deposits of limestone are older than the most re- 

 cent granite, while others are forming at the present 

 moment. The oldest specimens are coarse and of a 



