76 THE SOIL. 



through the soil, on the extent to which it is exposed 

 on the surface of particles, and probably on other 

 conditions concerning which we are in doubt, or of 

 which we are entirely ignorant, that the mere weigh- 

 ing and measuring of the laboratory, has very little, 

 if any, value to the practical farmer. 



"We can learn something of the capacities of the 

 soil from the character of the plants which grow 

 naturally upon it, and much more from its ability 

 to produce larger crops of one kind than of another ; 

 something from the effect of different mineral ma- 

 nures upon plants growing on it. 



The best use to which the farmer can apply the 

 teachings of chemistry is in making such improve- 

 ments as the foregoing indications show to be neces- 

 sary, and, above all, in giving to the soil for each 

 crop, or for each rotation of crops, the full equiva- 

 lent of the minerals that they take away. 



An examination, such as any farmer may make, 

 will show ns its deficiencies in mechanical character, 

 and we may apply the proper treatment to increase 

 fertility. In some instances the soil may contain 

 everything that is required, but not in the proper 

 condition. For instance, in some parts of Massachu- 

 setts, there are nearly barren soils which show by 

 analysis precisely the same chemical composition as 

 the soil of the Miami valley of Ohio, one of the most 

 fertile in the world. The cause of this great differ- 

 ence in their agricultural capabilities, is that the 

 Miami soil has its particles finely pulverized ; while 

 in the Massachusetts soil the ingredients are com- 



