Sect. I. Agriculture and Vegetation. 109 



principles muft be beftowed on it by gentle 

 degrees, and in very fmall quantities. Earth, 

 indeed, which has lain for fome time fal- 

 lowed, and is therefore well ftored with the 

 feeds of vegetation, is much in the fame 

 ftate with the earth of my experiments, 

 though not fo much faturated with the 

 nutritive principles, as mine was with the 

 different materials. Befides, the former is 

 conftantly receiving frem fupplies. That 

 I might approach nearer to the courfe of 

 nature, and fupply materials according to 

 the growth of the plants, the following ex- 

 periments were made. 



Exp. 32. Six pots were filled with poor, 

 light, virgin earth. Each pot contained 

 5 Ib. and 5 grains of heavy barley. N i . 

 had no mixture. N 2. was watered with 

 I dr. of faltpetre dirTolved in 3 oz. of water. 

 N 3. with the fame quantity of fea-falt. 

 N. 4. with the fame of Epfom fait, which 

 is compofed of the acid of vitriol, and the 

 earth, called magnefm alba. N 5. with 2 



dr. 



