13 
remained clear through the series, except for a flocculent precipitate 
which appeared to be ferric hydrate, and which was deposited from 
soil No. 428. 
The following table shows the amount of ammonia nitrogen 
removed from the original soils by distilled water: 
Ammonia nitrogen removed from the soils by distilled water. 
[Expressed in parts per million nitrogen in the percolate.] 
Percolates of 
100 cc. each. 
SoU 
No. 292. 
SoU 
No. 448. 
Soil 
.No. 428. 
Soil 
No. 474. 
100 
6.5 
5.7 
2.2 
2.9 
11.4 
8.4 
5.7 
5.7 
5.6 
13.4 
8.8 
5.4 
6.4 
7.3 
4.2 
4.4 
2.3 
3.0 
5.1 
200 
300 
400 
500 
From these data it may be seen that these soils possess the same 
general tendency to produce a solution of constant nitrogen content. 
In the following table may be observed the absorbing power of 
the soils for nitrogen in ammonium sulphate: 
Absorption of nitrogen from a solution of (NH 4 ) 2 S0 4 . 
[Expressed in parts per million nitrogen in the percolate.] 
SOLUTION USED CONTAINED 171 PARTS PER MILLION NITROGEN. 
Percolates of 
100 cc. each. 
Soil No. 
292. 
SoU No. 
448. 
SoU No. 
428. 
SoU No. 
474. 
100 
3.6 
2.6 
3.6 
5.6 
12.8 
14.7 
22.8 
15.8 
17.1 
18.7 
46.8 
64.4 
36.8 
39.6 
36.8 
51.5 
51.5 
39.6 
36.8 
42.8 
39.6 
64.4 
34.2 
39,6 
39.6 
51.5 
44.8 
36.8 
36.8 
39.6 
2.6 
2.6 
8.6 
7.4 
2.6 
4.5 
5.4 
12.1 
.12.8 
15.8 
200 
300 
400 
500 
600 
700 
800 
900 
1,000 
Percolates of 
100 cc. each. 
1,100 
1,200 
1,300 
1,400 
1,500 
1,600 
1,700 
1,800 
1,900 
Soil No. 
SoU No. 
SoU No. 
292. 
448. 
428. 
21.4 
42.8 
39.6 
51.5 
51.5 
51.5 
51.5 
46.8 
51.5 
51.5 
57.2 
64.4 
51.5 
57.2 
62.9 
68.4 
73.6 
68.4 
64.4 
68.4 
75.2 
64.4 
87.1 
87.1 
86.0 
94.4 
86 
Soil No. 
474. 
17.1 
46.8 
51.5 
46.8 
51.5 
57.2 
64.4 
73.6 
80.8 
SOLUTION USED CONTAINED 168 PARTS PER MILLION NITROGEN. 
2,000 
2,100 
2,200 
2,300 
2,400 
2,500 
2,700 
2,900 
70.8 
73.6 
78.8 
73.6 
76.4 
91.6 
73.6 
73.6 
123.6 
128 
117.9 
96.6 
105.2 
93.3 
117.1 
73.2 
114.1 
128.8 
128.8 
128.8 
121.2 
121.2 
128.8 
121.2 
117 
156.6 
174.2 
143 
156.4 
158.4 
167.8 
140.7 
3,100 
3,300 
3,500 
3,700 
3,900 
4,100 
4,300 
4,500 
119 
126 
134 
117.6 
135.2 
156.8 
186 
163 
138 
156.5 
148.9 
115.6 
152.4 
149.9 
88.8 
152 
152 
120.8 
147.2 
137.6 
120 
164.8 
171.2 
164.8 
112 
124.8 
148 
139.8 
137.6 
141.6 
120 
164.8 
Summary of above table. 
Soil No. 
Nitrogen 
added to 
100 gm. 
soil. 
Nitrogen 
fixed by 
100 gm. 
soU. 
Per cent 
of nitro- 
gen fixed. 
2y2 
Gram. 
0.6811 
.6811 
.6811 
.6811 
Gram. 
0. 2782 
.2290 
.2753 
.3015 
41 
448... 
34 
428 
40 
474 
44 
