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thefe has its peculiar plants, which will not grow 

 in the other, although they are few in number, 

 and of little known ufe. But the plants common 

 to both thefe foils will grow and thrive better in 

 loam, which is a middle fpecies of earth com- 

 pofed of thefe two extremes, partaking equally 

 of the good qualities of both, without the bad 

 ones. For this reafon, lands which partake of 

 the different properties of clay and fand, or which, 

 in other words, are a kind of compound wherein 

 the properties of clay and fand are fo united as 

 to correct each other, are generally the mod fruit- 

 ful, and produce the greateft mafs of vegetables. 

 This will more evidently appear, if it be confi- 

 dered in what manner plants and vegetables arc 

 nouriihed, and what it is that gives them bulk, 

 vigour, and firmnefs. 



When the feeds of plants are depofited in the 

 earth, certain degrees of warmth, air, and moif- 

 ture, are neceflary for the expanlion of their vef- 

 fels, and the extenfion and firmnefs of their fibres 

 and folid parts. For thefe purpofes ftifF clay, 

 and loofe fand, are both, while feparate, very un- 

 favourable; the former, by the clofenefs of its 

 texture, retains the water like a difh, admits too 

 little heat or air, and prevents the tender fibres 

 of young plants from ihooting freely to fuch 



diftances 



