72 CHRONICLES OF A CLAY FARM. 



with these mineral and ammoniacal substances, the 

 rapid development of the leaves will soon obtain 

 sufficient carbon from the air. The labours of the 

 Dung-cart, as at present carried on, even in the 

 most improved districts awkward and uneconomical, 

 exhibit, 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 turnings 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 plough- 

 ing-in of the Carbon is lavishly expended. And all 

 to little purpose. What portion the roots do take 

 up has to be oxygenated in the leaf and decomposed 

 again before plants will re-assimilate it : a subsidiary 

 faculty which bountiful nature has given them, with 

 different degrees of necessity for making use of it. 



But in autumn and winter manuring it is other- 

 wise. Decay is only slow combustion : and when you 

 are burying great cart-loads of carbonaceous ma- 

 nure in the soil before winter, you are making a 

 hotbed under ground, which will raise the tempera- 

 ture of the soil throughout the long reign of Jack 

 Frost, and preserve many a tender seed that would 



