176 CHEMICAL FERTILIZERS 



change in the gelatinous matter of the bone ; the nitro- 

 genous organic matter is partly peptonized and some amino 

 acids and ammonium sulphate is formed. 



Nitrogen in dissolved bone occurs in the forms of humic 

 nitrogen, glycine, leucine, alanine, argenine, lysine, histidine, 

 ammonia and unaltered protein. (See Table 20.) 



TABLE 20. 

 FORMS OF NITROGEN IN DISSOLVED BONES. 



Ammoniacal nitrogen 

 Humic nitrogen 



Basic nitrogen (argenine, lysine and histidine) 

 Amino nitrogen (glycine, leucine and alanine) 



Protein nitrogen 

 Total nitrogen 



0-03-0' 08 per cent. 



0-04-0-11 



o - 1 1-0-3 1 



0-38-1-12 



0-18-0-48 



0-78-2-10 



The sticky and almost gummy consistency of damp 

 dissolved bones is brought about by the presence of free 

 phosphoric acid and amino acids. 



Bone Compound Manures. Bones are often com- 

 pounded with other manures, such as superphosphate. 

 The manufacture of dissolved bones presents many difficulties 

 which add considerably to the expense, with little advantage 

 from the fertilizing point of view. When sulphuric acid 

 acts upon bones, it not merely dissolves the phosphate, but 

 it also dissolves the organic nitrogenous material, hence 

 dissolved bones contain tri-calcium phosphate, di-calcium 

 phosphate and mono-calcium phosphate, which behave 

 differently in the soil as regards their rates of availability. 

 The nitrogenous matter is also somewhat broken up, a little 

 ammonium sulphate is produced, some of the nitrogen is 

 converted into amides, amino acids or other soluble nitro- 

 genous matter, though a part remains tin-acted upon by the 

 sulphuric acid. There are consequently several forms of 

 nitrogen and phosphates present in dissolved bones ; this 

 mixture is undoubtedly of very considerable practical value 

 when used as a fertilizer. However accurately the farmer 

 may judge the need of his soil and crop, in no case can he 

 possibly foresee the weather for months ahead, and therefore 



