118 HORTUS GRAMINEUS WOBURNENSIS. 



assist in raising the art of Agriculture to the certainty of science, 

 if, in all experiments on the comparative produce of plants, the 

 intimate nature of the soil, as well as the properties of the subsoil, 

 were accurately determined. 



The following details are intended to shew the nature of those 

 soils which have been employed in this series of experiments on 

 grasses. 



I. Poor Siliceous Sandy Soil. 



400 grains, deprived of its moisture, consisted of 



Fine sand, chiefly siliceous - 337 grains. 



Carbonate of lime, or chalk 2 

 Decomposing vegetable matter destructible 



by fire. 4 

 Silica, or the pure matter of the earth of flints 32 



Alumina, or the pure matter of clay - 10 



Oxide of iron 5 



Soluble matter, principally saline 2 



Loss - - 8 



400 



II. Siliceous Sandy Soil, or Hungry Sand. 



400 grains, deprived of moisture, gave of 



Fine siliceous sand - 355 grains. 



Carbonate of lime, or chalk 4 

 Decomposing vegetable matter destructible 



by fire - - 6 

 Silica, or the pure matter of the earth of flints 1 1 



Alumina, or pure clay 6 



Oxide of iron 3 



Soluble vegetable and saline matters 3 



Loss - - 12 



400 



Obs. This soil, which was comparatively barren without the 

 frequent application of large portions of manure, and which had 

 only a transient effect, was permanently fertilized by the applica- 

 tion of tenacious clay, (No. IX.) 



