50 ORIGIN OF THE 



state, it would at once assume a different appear- 

 ance ; its bulk would be increased, its specific 

 gravity, or weight, would be lessened, and it 

 would assume the form of a white, pulverulent 

 mass, like that of quicklime, and thus remain, 

 prepared for other changes, to be indicated here- 

 after. Thus, we may suppose, all the metals on 

 and near the surface of the earth were acted on 

 by oxygen, while the crust continued in a suffi- 

 ciently heated state to decompose water ; and 

 that, during that time, all the metals were oxi 

 dized as fast as they changed from a fluid to an 

 igneous state. 



Thus, then, the earth's surface was prepared 

 for the reception of water, and the metallic ox- 

 ides fitted for the changes to be produced by 

 the action of water upon them. When the 

 temperature of the earth's exterior had been 

 reduced below the point required for the decom- 

 position of water, the heat was still so great as 

 to allow its approach only in a state of very rare 



