36 The Principles of Part. I. 



fruitfulnefs, yet it feems not to be the only 

 one. A great deficiency in fome of the 

 principles necefTary for vegetation, muft have 

 the fame effect. Thus farmers often sive 



D 



the name of //'// to indurated clays, and 

 particularly to thofe which they find below 

 the foil. The common farmer is afraid of 

 ftirring it up with the plough, becaufe it 

 is unfruitful : but the more judicious, will- 

 ing to deepen his foil, takes it up by little 

 and little, and finds that lime, dung, and 

 air, readily fertilife it. 



SECT. VIII. 



Of the mojjj foil. 



I Shall not enter into a difcuffion of the 

 origin and nature of mofs : it is now 

 allowed by every body to be a vegetable 

 fubftance. The following experiment is a 

 proof of it. 



Exp. \j. Haifa pound of powdered peat 

 gave me by diftillation, during the two firft 



hours, 



