AGRICULTURE WITH CHEMISTRY. 



141 



DRAINING, 



DRAINING of ground in the northern and humid 

 climate of Britain and Ireland is indispensably necessary, 

 and is the precursor to all culture and improvement of - 

 the soil. 



The principal ojedl in draining, is to free the surface? 

 from moisture at those seasons when it would prove 

 hurtful. 



Water constitutes the chief 'food of plants : it is decom- 

 posed in the process of vegetation, the plant retaining 

 the hydrogen or inflammable air, as \frell as the calca- 

 reous matter held in solution in the water, whilst the 

 oxygen or vital air, the other component part of water, - 

 is disengaged. 



Certain degrees of cold prevent the absorption of 

 water by vegetables. Water, during the continuance of 

 such degrees of cold, is of no service ; its presence at 



those 



