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an exhaufting cpp, prepares the land for another 

 cxhaufting crop, and efpecially if it be a hoeing 

 crop ; for by judicious management the land may 

 be conftantly cropped for many years in fucceflion, 

 without the intervention of a fallow every third or 

 fourth year, as was heretofore the pra6lice. 



Sect. VI. Of Improvements by Means of Manures 

 both Natural and Artificial. 



By a manure we underftand any fubftance which 

 being added to, or laid on land, increafes its ferti- 

 lity. This we conceive may be effedled by means 

 which operate very differently, therefore we fhall 

 treat of them under two diftincl heads : 



iji, Thofe that ad mechanically. 



Q.dly. Thofe that ad chemically. 



The fubftances which increafe the fertility of land 

 by mechanical means, are all thofe which by mere 

 addition and intimate commixion improve its tex- 

 ture. Thus ftrong, wet, heavy clay, by the mere 

 addition of iharp fand, or fine gravel, may be opened, 

 rendered more light and porous, and confequently 

 much more fertile. And light fandy and gravelly 

 foils, whofe open, loofe, incoherent texture fufFers 

 the rain, dews, &c. fuddenly to pafs through them, 

 are much improved by the addition of flrong bind- 



ing 



