13 



ammonia and 20 per cent bone phosphate etc. These various 

 grades figured on the basis of nitrogen and phosphoric acid, would 

 sive standards about as follows . 



Ammonia quotations may be changed to a nitrogen basis by mul- 

 tiplying by the factor .82. Quotations of bone phosphate may be 

 changed to phosphoric acid by multiplying by the factor .46. 



Drv Gtoiind Fish. This product is a refuse from the fish oil fac- 

 tories and is valued particularly for its high percentage of easily 

 decomposed organic nitrogen. Fish also contains an appreciable 

 amount of phosphoric acid. The average composition of fifty-nine 

 samples of this material shows a nitrogen content of 8.36 per cent 

 and phosphoric acid 8.87 per cent. 



Nitrate of Soda. This soluble quick acting material 



Nitrogen Com- is found in the crude form in large quantities, in the 



pounds. rainless regions of South America, more particularly 



in Chili and Peru. The crude material as mined, 

 contains varying quantities of nitrogen, ranging from two to four per 

 cent and over. This material is refined and comes on to the market 

 in light colored crystalline form containing about ninety-five per 

 cent nitrate of soda or about 15.5 per cent nitrogen. Nitrate of 

 soda is soluble in water and its nitrogen is in a form to be 

 readily assimilated by the growing plant. If used by itself 

 care should be taken that it does not come in direct contact with the 

 plant. If applied as a top dressing to grass and lawns, to promote 

 more even application it is well to mix with at least twice its bulk of 

 earth or other material. 



Blood is a refuse from slaughter houses and is considered one of 

 the most valuable sources of animal organic nitrogen. A good qual- 

 ity of blood contains from 10. to 10.5 per cent of easily decomposed 

 nitrogen. 



