Proceedings of Seventeenth Normal Institute 125 



The method of converting unavailable organic nitrogen into 

 available forms is very simple in theory and is not complicated in 

 practice. The organic material is mixed with snlphuric acid and 

 rock phosphate in the process of dissolving rock phosphate and 

 making acid phosphate. A considerable degree of heat is de- 

 veloped in the process; and, under the coml)ined action of acid 

 and heat, the nitrogen compounds of the organic material are 

 profoundly changed, forming new nitrogen compounds, wholly 

 dilferent in character from the original. Organic nitrogen com- 

 pounds produced in this way have an availability equal to or 

 greater than that of dried blood. In the trade, fertilizers pre- 

 pared in this way are usually called " processed fertilizers " or 

 " base goods," the word base being used in a chemical and not 

 commercial sense. 



