110 CRITIQUES AND ADDRESSES. [v. 



carbonic acid, water, ammonia, and mineral matters, 

 exactly equal in weight to the coal. But these are the 

 very matters with which Nature supplied the club-mosses 

 which made the coal. She is paid back principal and 

 interest at the same time ; and she straightway invests 

 the carbonic acid, the water, and the ammonia in new 

 forms of life, feeding with them the plants that now live. 

 Thrifty Nature ! Surely no prodigal, but most notable 

 of housekeepers ! 



