HORTUS GRAMINEUS WOBURNENSIS. 119 



HI. Heath Soil, or Black Siliceous Moor Soil. 



400 grains, deprived of moisture, gave of 



Fine sand, principally siliceous - - 315 grains. 



Decomposing vegetable matter - 65 



Silica - 9 



Alumina, or the pure matter of clay 2 



Oxide of iron 2 

 Soluble matter, principally vegetable extract 



and common salt 6 



Loss - 1 



400 



IV. Rich Siliceous Soil, or Rich Sandy Soil. 



400 grains, deprived of moisture, afforded of 

 Fine sand, chiefly siliceous and partly 



calcareous - 298 grains. 



Coarse gravel - 9 



Carbonate of lime, or chalk 3 



Carbonate of magnesia 1 

 Decomposing vegetable matter destructible 



by fire - 30 

 Silica - 31 

 Alumina, or the matter of pure clay 8 

 Oxide of iron 4 

 Soluble matter, consisting of vegetable ex- 

 tract and phosphate of lime 4 

 Loss - - 12 



400 



Obs. This soil, when on a clayey subsoil, produced large crops 

 for two successive seasons, but afterwards required a regular 

 supply of manure. When the subsoil was porous, or consisted of 

 gravel, the produce was very inferior. It is properly a hungry 

 soil, and requires an addition of clay and calcareous earth to 

 render it permanently fertile. 



