FOOD FROM THE SOIL AND FIOM THE AIR. S7 



must be in a soluble state, capable of immediate 

 employment in building up the plant. The farmer, 

 then, who knows best what is needed, knows how to 

 furnish it so as to have the best crops, and at the least 

 ea^iense. 



At -, ination of the leavra and of the roots of 

 a li' ', shows that it obtains a portion of its 



food air, and i from the earth. 



n. \c food. _r as it does of solid 



in the air, and must 

 U : -. j,h tlie roots. 



h. The organic food comes partly from the soil, and 

 partly from the air through the leaves. It may be 

 asked. How we know that plants get food through 

 t" ves? This is easilN '. If we place the 



leaves of a grow ' in a portion of 



air, the oomp' and 



I tie reexttiiineii -^ts a 



day or two aAerward, it will be found that its com- 

 position has changed: a portion of it has <'■- '■^•>' ;ired, 

 havini; been absorbed by the plant tlirou ives. 



c. If the confined ;i ' ' 



bonicacid, a portion h.i 1 



by oxvi?eiu 



d. it therr 15 no rnrhonir acid presen' . ater 

 or a. I. The i »• of 

 the:>c .,.- ._ . • tl. 



We have las in which 



plant" ■-•••- •' * ■* ■ - t 



oaoi' 



pot:- 



the ; ich we I 



diiui;..v iuw.^^.t. la their > 

 of plants, bat, as do tha iiK* 

 ma. of oomlniiatioii. 



