8 PKACTICAL FARM CHEMISTRY. 



posed upon our fathers. The foremost and most 

 formidable task which confronts us, is that of find- 

 ing and providing the raw materials required for 

 the manufacture of the crops which we wish to 

 produce, and this, too, at prices that will leave us 

 a fair profit. 



These raw materials are expensive. If we pur- 

 chase them carelessly, and apply them indiscrimin- 

 ately or injudiciously, we are apt to find ourselves 

 the losers in the transaction. Here agricultural 

 chemistry comes to our aid in solving many of the 

 problems concerning the needs of our crops, the 

 nature and value of the raw materials, and their 

 economical application. 



While every good farmer should familiarize him- 

 self with these cardinal points, he has no need to 

 be a chemist. He looks at this science from the 

 standpoint of the practical soil tiller, not from that 

 of the professional man of retorts and the laboratory. 



I have studied the problems here involved from 

 this same practical point of view; yet what I do not 

 know about chemistry would fill large volumes. 

 Such a confession at the very beginning is needed, 

 not only to shield myself against the assumption of 

 undue responsibility, but also to serve as a warning 

 for the reader against extravagant expectations. 



The professional chemist rarely knows how to 

 grow a single farm crop successfully and profitably; 

 yet, the success of modern farming depends in a 

 large measure on the proper application of know- 

 ledge developed by the experiments in the labora- 

 tory. The chemist can tell us the exact quantities 

 of the various elements which constitute a plant, or 

 a grain, or a fruit. He can also tell us how much 

 of each of these elements or substances is contained 



