ON FALLOWING. 177 



demonstration ; but in determining this, we must 

 take into consideration an axiom, that (as has 

 been before observed) seems not to have occurred 

 to Sir Humphry Davy ; viz. that plants may be 

 overfed, and diseased by unwholesome food. We 

 will therefore suppose that part of a foul field, 

 even of a middle quality, were laid up in fallow ; 

 and part manured, or laid down to turnips, and 

 fed off with sheep ; and both ploughed without 

 any further manuring to either part, and cropped 

 with wheat, — Query, would not the quality of 

 the grain and straw of the fallow land make up 

 for the difference in bulk on the other : taking 

 into consideration the casualties of rust, and 

 the being lodged or blown down ? and whether 

 the clean state of the land after fallowing would 

 not more than compensate the difference of 

 profit arising from the turnips ? 



This is the simple question at issue, and which 

 cannot be fairly answered, without reference to 

 the state of the land which is to be submitted to 

 the operation. K the land be foul, or full of 

 vegetable matter, both organised and ineit, and 

 withal stiff and wet; on the principles already ex- 

 plained, fallowing must certainly be a beneficial 

 operation ; but if the land be free from vegetable 

 matter; the idea of increasing the fertility of the 

 soil, by a year*s exposure to the atmosphere, can- 



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