18 
acid, and also those split off in the hydrolysis of the humus precipitate, 
may reasonably be considered as being made up of amid, basic, and 
nonbasic nitrogen compounds. We have, therefore, calculated the 
amounts of nonbasic nitrogen in these portions of humus. The 
results are shown in the following table: 
Nonbasic nitrogen in humus. 
In filtrates from HC1 
precipitates. 
In hydrolyzed humus 
precipitates. 
Total. 
Soil No. 
Per cent 
of soil. 
Per cent 
of nitro- 
gen in 
filtrate. 
Per cent 
of humus 
nitrogen. 
Per cent 
of soil. 
Per cent 
of nitro- 
gen in 
solution. 
Per cent 
of humus 
nitrogen. 
Per cent 
of soil. 
Per cent 
of humus 
nitrogen. 
347 
0.196 
.148 
.052 
.063 
.055 
.031 
.027 
.046 
62.22 
59.92 
40.31 
53. 84 
52.38 
44.28 
39.13 
68.65 
25.32 
25.08 
11.84 
27.87 
25.58 
21.09 
21.26 
37.39 
0.249 
.213 
.203 
.071 
.061 
.033 
.035 
.011 
.003 
68.78 
73.70 
75.18 
71.00 
64.89 
50.00 
57.37 
125.00 
19.67 
32.17 
36.10 
46.24 
30.97 
28.36 
22.45 
27.56 
18.78 
15.18 
0.445 
.361 
.255 
.134 
.116 
.064 
.062 
.057 
57.49 
428 
61.18 
379 
58.08 
406 
58.84 
447 
53.94 
345 
43.54 
343 
48.82 
405 
45.17 
292 
52.59 
25.05 
64.84 
31.98 
53.38 
i Not included in averages. 
These data show the relatively large amounts of nonbasic nitrogen 
contained in humus. On the average about 25 per cent of the humus 
nitrogen occurred in the original humus solutions as nonbasic nitrogen 
compounds, or 52.59 per cent when calculated to the percentage of 
humus nitrogen soluble in dilute hydrochloric aci'd. The solutions 
obtained upon hydrolyzing the humus precipitated by dilute hydro- 
chloric acid yielded a still greater amount of nonbasic nitrogen. 
On an average 64.84 per cent of this nitrogen occurred as nonbasic, 
which, when calculated to percentages of the total humus nitrogen, 
amounts to 31.98 per cent. By adding the nonbasic nitrogen in 
these two portions of humus it is found that 53.38 per cent of the 
humus nitrogen is made up of nonbasic nitrogen compounds. By 
referring to the data previously presented (p. 9) it will be seen that 
the relative amounts of nonbasic nitrogen in humus are somewhat 
less than the amounts of nonbasic nitrogen obtained in the hydrolysis 
of the soil as a whole. 
Considering the different groups of nitrogen compounds as obtained 
from the different portions of humus, the preceding data show that the 
humus contained slightly less amid, basic, and nonbasic nitrogen than 
were split off upon hydrolyzing the soil nitrogen as a whole, but, on 
the other hand, the humus nitrogen bodies as such are made up of 
relatively more amid and basic nitrogen than the soil nitrogen as a 
whole. In other words, the nitrogen of soils soluble in 3 per cent 
sodium hydrate is bound up in bodies differing somewhat from the 
