298 AGRICULTUEAL EXPERIMENT STATION. [Jan, 



Johnson, Farrington and Wiuton,* instead of using Stut- 

 zer's solution, dissolved 5 grams of Golden Scale Pepsin in 

 1,000 cubic centimeters of 0.2 per cent, hydrochloric acid, 

 and digested a variety of substances in this fluid. Their in- 

 vestigation is the most valuable we possess in this direction. 

 A few of their results may be cited : — 



Per Cent, of Nitrogen, 

 disested. 



. 97.30 



. 71.20 



. 23.40 



. 35.90 



. 33.30 



Dried blood (two samples) , 



Dry ground fish, .... 



Leather No 3,f 



Leather treated by benzine process, 



Leather treated by superheated steam. 



Mixed fertilizer A, containing 2.02 per cent, leather 



nitrogen, 23.40 



Mixed fertilizer B, containing 2.00 percent, leather 



nitrogen and 1.75 per cent, blood nitrogen, . . 55 . 60 



In this connection it might be in place to mention the ex- 

 periments recorded on the putrefaction of ammoniates, at 

 first suggested by A. Morgen.J He put leather and horn 

 meal in water to which a small amount of fecal extract had 

 been added, and then allowed the solution to stand for thirty- 

 one days at 30° C. The nitrogen made soluble was then 

 estimated : — 



In Experiment I., 10 grams material -|- 1,000 cubic centimeters water 

 were used. 



In Exj^eriment II., 5 grams material -[-1,000 cubic centimeters water 

 -|- 5 cubic centimeters fecal extract. 



In Experiment III. the same, with 10 grams material -\- 5 cubic centi- 

 meters fecal extract. 



Per Cent, of 

 Soluble Nitrogen. 



Leather meal, average of three exijeriments, . . 34.56 

 Horn meal, average of three experiments, . . 61.62 



Johnson * repeated Morgen's work on a very large number 

 of substances ; a few of the results are given below. He 

 allowed his solution to stand two weeks : — 



* Loc. cit. 



t Fine and brittle, but method of preparation not known. 



X Landw. Vers. Stat., 1880, 50 ; Biedermann's Centralblatt, 9, 801. 



