74 ARRANGEMENT OF CHEMICAL PRINCIPLES, 



Whatsoever, therefore, constitutes the grand 

 invigorating or accumulating principle in the food 

 of plants, must be reducible to a soluble state, 

 or be placed in a state of minute divisibility. 



Although water in its pure state contains hy- 

 drogene and oxygene only, as it is necessarily 

 brought in contact with, or made to pass through 

 animal and vegetable substances, which are 

 always scattered over the surface, or contained 

 in the soil, before it can come within reach 

 of the roots, it dissolves, or combines and 

 carries with it the carbonaceous matter. 



Plants possess the power of decomposing wa- 

 ter, and in the composition of their own various 

 substances, of retaining and apphdng the carbon, 

 hydrogene, and earth, and a portion of oxygene, 

 and at the same time of emitting the superfluous 

 oxygene as excrementitious. 



Animals by respiration decompose the atmo- 

 spheric air, retaining the oxygene, and emitting 

 the nitrogene. 



Animals and vegetables when deprived of life, 

 and left to spontaneous decay, are decomposed 

 by fermentation, and by this process, carbon, and 

 earth are deposited, and oxygene, w^hich is in- 

 creased by absorption, is disposed of, by part 

 forming carbonic oxyde, and part carbonic acid 

 gas : the hydrogene and nitrogene are emitted 



