KOCKS AND HILLS CRUMBLING DOWN. 91 



some rock of the same substance, perhaps many 

 miles from the spot where we obtained the 

 specimen. 



Enough has now been said to exhibit the 

 powerful, although silent influences which, un- 

 der the direction and constant control of the 

 Allwise Creator, are incessantly at work in 

 altering and destroying some of the most ap- 

 parently unchanged and unchangeable objects 

 which surround us. It has been seen that the 

 rocks and hills are slowly crumbling away, and 

 the forces which perform this duty have been 

 shown to consist only of water, air, and carbonic 

 acid. While mountain, rock, and valley, lose 

 by the touch of water and gas, can the softer 

 soil resist their influence ? or are these alone 

 affected by the powers of chemistry and the 

 movements of time ? 



