76 CHEMISTRY, GEOLOGY 



An equal weight of lime is more effective upon 

 drained, or dry land, than upon a soil which 

 contains an excess of water. Lime should be 

 applied to the soil at such intervals, and in such 

 quantity, as % may maintain in the land a full 

 supply of this inorganic and most necessary ele- 

 ment. The application of lime requires repeti- 

 tion, because the crops take up and carry off an 

 amount proportionate to their wants, annually ; 

 because some portion of it sinks into the subsoil, 

 and is there useless ; and, lastly, because the 

 rains are constantly washing some portion of it 

 out of the land. 



THE COMPOSITION OF CROPS. 



The several kinds of grain mainly consist of 

 three substances, starch, gluten, and oil. or fat. 

 In one hundred pounds of wheat-flour there are 

 about fifty pounds of starch, ten pounds of 

 gluten, and two to three pounds of oil. One 

 hundred pounds of oats yield about sixty pounds 



Questions. Upon what land is lime most effective? 

 How often should the soil be limed ? Why does the lime 

 need to be repeated ? Of what do the several kinds of grain 

 chiefly consist ? In what proportions are these found in one 

 hundred pounds of wheat-flour ? In one hundred pounds 

 of oats ? 



