Sect. III. Agriculture and Vegetation. 13 



fermentation, or interline motion, which 

 continually goes on in this foil, being , in r 

 creafed by the addition of the water : for 

 all bodies muft have a certain degree ol 

 \vatry particles, in order to make the fer- 

 mentation go on properly. 



IT is obferved of all foils, the moiTy and 

 boggy ground excepted, that the blacked 

 are the richeft. This' colour gives it a 

 ftrong prefumption, that thefe foils con* 

 tain much fat and oleaginous matter; for 

 all foffil and vegetable oils, when they have 

 a great admixture of eartl;, are of this co- 

 lour. It is owing likewiie to thefe oils, 

 that all vegetable or animal fubftances gain 

 a black colour when in the road to putre- 

 faction, The unctuofity too of this foil, 

 a quality of it which is remarked by farrjnr 

 ers, is a proof of its oleaginous nature. 

 This black colour will make it reflect fewer 

 of the fun's rays, and fo make it 

 tible of a greater heat, than .foils 

 are of a lighter colour, 



Bt 



