SUBSTANCES TAKEN FROM THE SOIL. 231 



TABLE X. ANALYSIS OF THE ASH OF SOME OF THE 

 NATURAL AND ARTIFICIAL GRASSES. 



A careful examination of the analyses of the ash, or 

 the inorganic constituents of the grasses, will reveal 

 the fact that some important substances are taken from 

 the soil in large quantities, and if the grass is removed 

 in the form of hay, that these must in some way be 

 restored in manure, or exhaustion will follow. Among 

 these are large percentages of silica, which is taken up 

 in solution with water. Phosphoric acid is removed in 

 large quantities, generally found in combination with 



