1895.] 



PUBLIC DOCUMENT — No. 33. 



299 



Blood, . 



Fish, 



Fish, 



Bone, 



Leather No. 3, 



Steamed leather, 



" Prepared ammoniate " (pr 



obably leathei-), 



Per Cent. Nitrogen 

 Soluble. 



76.80 

 78.10 

 54.60 

 79.00 

 12.20 

 42.30 

 35.70 



Johnson remarks that ' ' this test of putrefaction draws the 

 same line between those classes of ammoniates that was 

 drawn by the pepsin digestion." 



C. XlTRIFICATION EXPERIMENTS WITH LEATHER. 



These experiments were carried out by Mllntz and Girard * 

 with quite a numlier of nitrogen-containing substances. 

 They were conducted in the laboratory, and care was taken 

 to see that the soil was properly aired, and that moisture, 

 temperature, etc., were favorable to the experiment. Ordi- 

 nary soil was at first used, the amount of nitrates present 

 being carefully noted, and a small amount of the substances 

 to be nitrified then added. After a certain time the nitrates 

 were washed out with water and estimated. A very short 

 resume is here presented : — 



Nitrogen NUrificd^ per 100 Parts of Nitrogen added to the Soil. 



In order to study the influence of difterent kinds of soil 

 upon the process of nitrification, the experiment was re- 

 peated with soils from various sections of the country : — 



* Ann. Agron., 17, 290; Agric. Science, 7, 408-412. Deherain, Chimie Agricole, 

 page 621. 



