296 AGRICULTURAL EXPERIMENT STATION. [Jan. 



results above given to encourage the belief that roasted 

 leather can have any definite money value as a manure." 



Wagner * has made an exhaustive study of the value of 

 difl'erent forms of nitrogen, having conducted 366 plat and 

 pot experiments. The experiments were carried on for 

 sev(!ral successive years in a soil rich enough in lime to 

 favor nitrification, and every effort was made to have the 

 conditions equal in all cases. But a very brief resume can 

 be given at this time. One experiment was conducted for 

 three successive years upon small plats of soil. Summer 

 rye was planted the first year, summer wheat the second and 

 carrots the third year. Placing the value of the returns 

 from the nitrate of soda plats at 100, the other forms of 

 nitrooen had the followino- relative worth : — 



Experiments were also conducted in pots with various 

 soils, but the results cannot be noticed here. 



In concluding his remarks relative to this subject Wagner 

 says : — 



AVheii I take all things into consideration, ... I think I 

 may present the following figures as an expression of the rela- 

 tive value of nitrogen in different forms of nitrogeu-coutaiuiug 

 material : — 



Nitrate of soda, .... 

 Sulphate of ammonia. 

 Blood, horn meal and green crops, 

 Fine-ground bone, fish and tankage. 

 Stable manure, .... 



Wool dust, 



Leather, 



100 

 90 

 70 

 60 

 45 

 30 

 20 



* Die Stickstoff-diingung, etc., page 255. 



