THE KEY-NOTE OF GOOD FARMING. 29 



such abundant quantities that it is not necessary to add them in 

 manure, or they may be so cheaply and easily obtained that they 

 are of secondary importance in practice. 



Therefore, it is chiefly desirable for the farmer to give his atten- 

 tion to the sources from which the plant may derive its three 

 remaining ingredients, — nitrogen^ phosphoric acid^ znd potash. With- 

 out these none of our cultivated plants will attain their full de- 

 velopment, and when a soil ceases to produce good crops, (supposing 

 it to be in good mechanical condition,) it is almost always in con- 

 sequence of a deficiency of one or more of them.' I propose 

 therefore to restrict my remarks about agricultural chemistry to a 

 consideration of these three substances, — without a proper manage- 

 ment of which no man can be an entirely practical farmer. He 

 raises no crop which does not contain them, he sells no animal or 

 vegetable product which does not take them from his farm, and 

 he has no soil so rich that they, or some of them, need not be 

 returned to it to keep up its fertility. Whatever course of culti- 

 vation he pursues, he should never lose sight of these elements, 

 and he should pay no greater heed to the dollars and cents that he 

 receives and pays out than to the nitrogen, phosphoric acid, 

 and POTASH which constitute his real available capital, and whose 

 increase and decrease mark the rise and fall of his true wealth. 



Other constituents of his soil are removed in the crops and in 

 the animal products sold, but they are such as are usually con- 

 tained by the soil in larger quantities, or as may be cheaply pro- 

 cured from other sources, and they are rarely removed to a suf- 

 ficient extent to cause an impoverishment of the land. 



The elements spoken of above, as well as lime and other min- 

 eral manures, will be more fully treated in the chapter on Ma- 

 nures ; but I desire, at the outset of my work, to call especial 

 attention to the characteristics and uses of these three cardinal 

 elements. 



