100 ON MANURES. 



ted water, before it would be in part lost by evaporation. 

 Liebig states that cold water dissolves only one ten 

 thousandth part of its own weight of vegetable mould. 

 Dr. Dana remarks, " Liebig takes it for granted that it 

 is rain only that is to dissolve geine and geates. He 

 says, it is not enough. We offer him an abundant source 

 in the fountain of water from geine. He says, it is not 

 enough. We add, if indeed we should not begin there, 

 the action of growing plants upon silicates, evolving ba- 

 ses whose action upon geine renders it easily soluble. I 

 think these causes of the solubility of geine enough, and 

 no small argument to prove that geine exercises other 

 functions in soil besides evolving carbonic acid. Geine 

 ceasing, barrenness follows. When Raspail and Liebig 

 prove the contrary, I'll believe ourselves wrong in our 

 views." 



Amid these conflicting theories of the mode of its op- 

 eration, one thing is certain, the presence of a large per- 

 centage of geine in soils, provided it be by culture duly 

 exposed to the influence of air, alkalies, salts, &c., in- 

 sures the greatest fertility. And farmers will do well 

 not to let the theory that vegetables feed on air prevent 

 them from supplying them with more substantial food, 

 compost manures, in which, at least for light gravelly 

 soils, peat, muck, or other substances rich in geine, 

 forms a large proportion. It seems to me that Liebig's 

 theories, when divested of contradictory appearances, 

 shew conclusively that geine or its elements are the pri- 

 mary food of plants, — that the absorption of these by 

 the rootlets developes those organs, the leaves, &c., 

 which become in turn capable of absorbing from the at- 

 mosphere the same elements in even a larger quantity 

 than is received by the roots, and appropriating them to 

 the growth of the plant, thereby, in the end, by one of 

 those beautiful laws of compensation everywhere met 

 with in natural science, it becomes enabled to repay to 

 the soil, with interest, the geine it takes from it. Deprive 

 the plant of a soil containing geine, or carbon otherwise 

 combined, and no organs can be developed to imbibe the 

 same elements from the atmosphere. 



