H4 *fhe Principles of Part III. 



taught me the good effects of the acid of 

 vitriol faturated with an alkaline fait; the 

 prefent teaches me, that the fame acid fa- 

 turated with a particular abforbent earth, 

 promotes fertility. Hence I concluded, in 

 part 2. feet. ,3. that marl added to the 

 fame acid, after the poifonous chalybeate 

 particles were feparated from it, would ra- 

 ther be of fervice than difiervice to the 

 foil. 



Cor. 4. Quick-lime, faturated with fpirit 

 of nitre, added in fmall quantities, and well 

 diluted with water, appears to have hurt the 

 vegetative power of the foil. Was it ufed 

 in too great quantity ? or did it not meet 

 with what is as necefTary to vegetation as 

 itfelf, a due proportion of oleaginous par- 

 ticles, which nature always fupplies in pro- 

 portion as me fupplies the falls ? The latter 

 feems to have been the cafe, from the fol- 

 lowing corollary. 



Cor, 



