96 CHRONICLES OF A CLAY FARM. 



before it will have set free the Mineral and Ammo 

 niacal parts, which together constitute, when dis 

 solved by water, the suction-food of roots. 



Liebig asserts, that if the roots are duly supplied 

 with these mineral and ammoniacal substances, the 

 rapid development of the leaves will soon obtain 

 sufficient carbon from the air. The labors of the 

 Dnng-cart. as at present carried on, even in the most 

 improved districts awkward and uneconomical, ex- 

 hibit, under more backward management, a system 

 of elaborate extravagance and loss, which the least 

 chemical acquaintance with what we are about, 

 would render utterly intolerable. By frequent turn- 

 ings in the yard, and long exposure in the field, 

 every opportunity for the escape of the Ammonia 

 and every toil in the lifting, hauling, forking, and 

 plowing-in of the carbon is lavishly expended. And 

 all "free gratis for nothing," if plants imbibe little 

 carbon at that end. What portion the roots do take 

 up, has to be oxygenated in the leaf and decomposed 

 again before plants will reassimilate it : a subsidiary 

 faculty which bountiful Nature has given them, with 

 different degrees of necessity in making use of it. 



But it is otherwise in autumn and winter manur- 

 ing. Decay is only slow combustion: and when 

 you are burying great cart-loads of carbonaceous 



