1 % ^Ls Principles of Part I. 



again contain the quantity taken out. 

 This muft be owing to a fermentation of 

 the putrefactive kind, carried on, in a fmall 

 degree, in thefe rich foils, whenever the 



o ' 



air is admitted to them : for without air 

 there can be no inteftine motion. This 

 continual tendency to putrefaction, in Ibme 

 of the particles of this foil, will appear 

 more plain from its colour, and quantity 

 of oil, the only fubject of corruption. 

 Hence it follows, that there muft be a de- 

 gree of heat in this foil, in proportion to 

 the progrefs of the putrefactive fermenta- 

 tion, and independent of the fun, or na- 

 tural heat of the internal parts of the 

 earth. 



THIS foil admits the water eaiily, and 

 fwells like a fptinge after it has taken the 

 rnoiflure in. This quality is peculiar to 

 good foil. It contracts again when dried. 

 Hence naturalifts conclude, that this foil 

 confifts of fpungy and fwelling particles. I 

 rather chufe to attribute this fwelling to the 



fer- 



