20 



Wood of vegetation. It carries nourishment from the 

 ground to the stem, to the leaf, to the seed. In its 

 solvent action rocks become the food of man ! 



When the soil is dry, no mouldering down to a 

 finer dust, no disintegration of minerals, no decay of 

 any kind can be discovered, every .atom, apparently 

 stationary, seems fixed and firm as adamant. 



Travelers tell us, that in the dry air of Egypt, the 

 old monuments erected thousands of years ago, are 

 just as fresh and smooth in outline as if the chisel had 

 finished them but yesterday. But when some of 

 these relics of the past were transported to Paris, in 

 the moist climate of France, they soon began to 

 change, and atom by atom to crumble away. 



Dr. Youmans says : "It has been shown by ex- 

 tensive experiments that no species of rock whatever 

 will resist the solvent action of water impregnated 

 with carbonic acid." Atlas of Chemistry, p. 50.- 



What an instructive less-m ! How valuable to the 

 farmer ! Such knowledge, how exceedingly useful. 

 ThM in our daily effort to convert the earth upon 

 which we tread into a flourishing vegetation we can 

 combine and concentrate the forces oi nature by 

 covering the ground, that moisture and carbonic acid 

 may do a great work for man. 



Yes, so vastly important is the benefit that may be 

 derived from mulching with green manures that we 

 not only see it in the augmentation of our crops, and 

 the improvement of our tillable soil, but it may be 

 observed in the condition of the forests around us. 

 Those that have a deposit of leaves undisturbed for 

 years, about their roots, make an annual growth 

 much greater than those which have been robbed of 



