8 
rapidly during the first four days than dried blood, after which time 
the yields decreased; while cottonseed meal and linseed meal each 
gave lower yields, the highest concentration of ammonia from the 
former being on the fourth day and from the latter on the sixth day. 
Direct distillation with magnesia after two days yielded slightly 
more ammonia in most instances than the other methods. Later 
the results by the different methods were fairly concordant. With 
only a few exceptions, as large amounts of ammonia were obtained 
by distilling the hydrochloric acid extracts with magnesia as with 
caustic soda. a The above data therefore give but little indication 
that hydrolysis was more rapid than ammonification. 
SERIES II — AMMONIFICATION IN SOIL. 
This series of experiments was conducted with the fresh heavy 
clay soil from which the infusions were made in the previous 
series. One-hundred-gram portions were each thoroughly mixed 
with 1 gram of the nitrogenous materials and 1 gram of calcium car- 
bonate and placed in tumblers. Sterile water was added so as to 
bring the moisture up to 25 per cent. After incubating at 28° C. 
the ammonia was determined as in the previous series. On the ninth 
day the nitrate was also determined in separate portions by the phenol 
disulphonic acid method, and was added to the average ammonia at 
this period in estimating the total ammonification. 
Amount of ammonia formed in soil from different substances. 
Method of determination. 
Nitrogen as ammonia from— 
Period of incu- 
bation. 
Casein. 
Dried 
blood. 
Soy bean 
cake 
meal. 
Cotton- 
seed 
meal. 
Linseed 
meal. 
2 days 
Distilled directly with MgO 
HCl solutions distilled with MgO.. 
HCl solutions distilled with NaOH 
Distilled directly with MgO 
HCl solutions distilled with MgO.. 
HCl solutions distilled with NaOH 
Distilled directly with MgO 
HCl solutions distilled with MgO.. 
HCl solutions distilled with NaOH 
/HCl solutions distilled with MgO.. 
\HC1 solutions distilled with NaOH 
Nitrate N 
Mg. 
50.8 
38.1 
/ 40.0 
\ 40.3 
57! 7 
/ 65.5 
\ 60.5 
68.6 
59.1 
/ 56.6 
\ 56.8 
59.1 
56.8 
Mg. 
4.1 
2.2 
4.2 
4.5 
24.1 
18.5 
21.3 
21.6 
42.4 
40.9 
33.6 
35.2 
<>38.9 
49.0 
Mg. 
7.8 
5.6 
8.1 
7.8 
21.8 
20.4 
17.4 
19.9 
29.4 
26.3 
28.3 
23.8 
26.6 
27.2 
Mg. 
5.6 
4.8 
4.2 
5.6 
11.5 
9.5 
8.1 
10.1 
10.6 
9.2 
10.6 
9.8 
7.8 
7.3 
Mg. 
2.0 
4 days 
4.2 
2.8 
11.2 
9.5 
6 days 
9.5 
10.6 
13.9 
10.9 
9 days 
10.9 
11.2 
7.0 
9.8 
4.4 
62.3 
50.2 
7.4 
56.4 
42.4 
7.0 
33.9 
40.9 
6.3 
13.8 
27.1 
4.6 
9 days 
Total ammonification 
Per cent of total N converted 
into NH 3 . 
13.0 
26.0 
o It is not surprising that practically as much ammonia was obtained by distilling the solutions with 
magnesia as with caustic soda, since the acid amids are decomposed by each alike, and only two other 
protein cleavage products, cystin and arginin, yield ammonia to caustic soda. Cystin occurs in very small 
amounts in most proteins. 
b Not used in average. 
