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. If the land be foul, or full of 

 vegetable matter, both organised and inert, 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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