CULTIVATION. l;i[ 



it of a portion of its heat, which is carried down to 

 equalize the temperature for the whole d.-pth. 

 heat of the rain-water itself is gi\vn ], to th,- 

 leaving the water from one to ten .! 

 wlien it passes out of the drains, than when received 

 by tlie earth. 



This heating of the lower soil of course ran 

 more favorable to vegetation. 



4. Under-draining hank-it* M< d 



root* ami oth-i' uiy.rntr in, iff*, r* in (I,,- ,vo,7, l, v ad- 

 mitting increased quantities of air, thus supplying 

 oxygen, which is as essential in decay as it is in com- 

 bustion. It also allows the resultant [ ; de- 

 composition to pass away, leaving the air around 

 the decaying substances in a condition to continue 

 the process. 



This organic decay, besides its other benefits, pro- 

 duces an amount of heat perfectly perceptible to the 

 smaller roots of plants, though not so to us. 



5. Draining accelerates the <ll.f'int>(ii-<it'>n ,// 

 minerals in the soil, by admitting water and o\ 



to keep up the process. This disintegration is ne- 

 eessary to fertility, because the roots of plants can 

 feed only on matters dissolved from i\ and 



the more finely we pulverize the soil, the more sur- 

 face we expose. For instance, the interior < : 

 can furnish no food for plants; while, if it I 

 finely crushed, it might make a fertile soil. 



Anything tending to open the soil to the air facili- 

 tates the disintegration of its particles, and thereby 

 increases its fertility. 



