MINING AND MANUFACTURE OF 

 FERTILIZING MATERIALS 



CHAPTER I 

 CHEMISTRY OF FERTILIZERS 



The Four Fundamental Laws Nitrogen Potash Phos- 

 phoric Acid Lime Terms Used in Analyses Loss of 

 Fertilizer in Soils Indirect Fertilizers Direct Ferti- 

 lizers. 



THE systematic scientific study of agriculture 

 was commenced about sixty years ago, and it 

 is to the celebrated German agricultural chem- 

 ist Justus von Liebig that we owe the following 

 four elementary laws, which are the foundation 

 of the best modern practice. 



I. A soil can be termed fertile only when it 

 contains all the materials necessary for the nu- 

 trition of plants, in the required quantity, in 

 the proper form. 



II. With every crop, a portion of these ingre- 

 dients is removed. A part of this is again added 

 from the inexhaustible store of the atmosphere; 

 another part, however, is lost forever if not 

 replaced by man. 



