12 
BULLETIN 1311, IT. S. DEPARTMENT OF AGRICULTURE 
Table 2. — Chemical composition of soils from wliicli colloid: 
Continued 
were extracted — 
Quan- 
titv 2 
of 
col- 
loid 
C0 2 
Or- 
in 
from 
Igni- 
H2O 
110° 
gan- 
soil 
No. 
Soil type 
Depth 
P2O6 
SO3 
CI 
car- 
tion 
ic! 
N 
indi- 
bon- 
loss 
mat- 
cated 
ates 
ter 
by 
water 
ab- 
sorp- 
tion 
ratio 
P. ct. 
P.ct. 
P.ct. 
P. ct. 
P. ct. 
P. ct. 
P.ct. 
P.ct. 
P.ct. 
1 
Carrington loam, Iowa 
0"-12" 
0.14 
0.10 
0.052 
0.00 
6.52 
2.62 
3.94 
0.27 
32.4 
2 
Carrington loam, Iowa 
15"-36" 
.06 
.04 
.031 
.00 
2.22 
1.52 
.71 
.05 
29.4 
3 
Cecil clay loam, Maryland 
0"- 7" 
.09 
( 3 ) 
( 3 ) 
.00 
8.11 
1.98 
( 3 ) 
( 3 ) 
19.3 
4 
Cecil clay loam, Georgia 
0"- 9" 
.06 
.02 
.020 
.00 
2.89 
1.17 
.56 
.03 
10.2 
5 
Cecil clay loam, Georgia 
9"-18" 
.05 
.02 
.037 
.00 
5.50 
.92 
1.08 
.04 
31.0 
6 Chester loan"!, Virginia 
0"- 7" 
.09 
.07 

.00 
4.86 
1.05 
1.68 
14.3 
7 i Chester loam, Maryland 
0"- 8" 
.04 
.03 
.062 
.00 
3.09 
.89 
1.62 
.07 
8.5 
8 Chester loam, Maryland 
8"-32" 
.15 
.03 
.030 
.00 
4.62 
2.78 
.78 
.03 
24.8 
9 Clarksville silt loam, Kentucky.. 
0"-10" 
.08 
.08 
.040 
.00 
4.09 
1.90 
.96 
.10 
23.3 
10 ! Clarksville silt loam, Kentucky.. 
10"-36" 
.27 
.08 
.030 
.00 
3. 65 
1.49 
1.02 
.04 
25.5 
14 Hagerstown loam, Maryland 
0"- 8" 
.13 
.03 
.025 
.14 
3.69 
1.12 
1.48 
.13 
16.7 
15 ! Hagerstown loam, Maryland 
8"-30" 
.11 
.02 
.032 
.00 
4. 36 
1.85 
.52 
.06 
32.0 
16 | Houston black clay, Texas 
0"-12" 
( 3 ) 
( 3 ) 
( 3 ) 
5.13 
13.39 
7.59 
( 3 ) 
( 3 ) 
55.6 
17 Huntington loam, Marvland 
0"- 8" 
.25 
.08 
.018 
.00 
6.50 
1.95 
3.88 
.20 
23.1 
18 
Huntington loam, Maryland 
8"-30" 
.14 
.06 
.074 
.00 
4.79 
2.15 
1.03 
.20 
20.8 
20 
Lufkin clay, Mississippi 
5"-36" 
.06 
.03 
( 3 ) 
.00 
3.78 
7.61 
( 3 ) 
.06 
21 
Manor loam, Maryland 
0"- 7" 
.17 
.08 
• .032 
.00 
5.00 
1.24 
1.68 
.11 
"iai 
22 
Manor loam , Maryland 
7"-20" 
.10 
.09 
.029 
.00 
5.05 
1.10 
1.38 
.03 
18.6 
23 
Marshall silt loam, Nebraska 
0"-14" 
.21 
.12 
.045 
.00 
6.94 
3.21 
4.10 
.23 
27.3 
24 
Marshall silt loam, Nebraska 
14"-18" 
.30 
.06 
.032 
.00 
5.42 
6.54 
1.91 
.10 
34.3 
25 
Miami silty clay loam, Indiana.. 
0"-10" 
.29 
.03 
.015 
.00 
4.15 
3.24 
1.65 
.09 
22.7 
26 
Miami silty clay loam, Indiana _. 
10"-24" 
.15 
.0-3 
.039 
.35 
5.91 
6.01 
1.29 
.07 
50.1 
27 
Norfolk fine sandy loam, North 
Carolina 
0"- 8" 
.02 
.03 
.040 
.00 
3.74 
.88 
2.40 
.08 
10.7 
28 : Norfolk fine sandy loam, North 
Carolina 
12"-36" 
.01 
.06 
.017 
.00 
3.08 
1.01 
.39 
.04 
20.5 
29 
Ontario loam, New York 
0"-12" 
.15 
.09 
.033 
.00 
4.66 
2.45 
2.87 
.18 
18. 5 
30 
Ontario loam, New York 
12"-22" 
.21 
.05 
.040 
.00 
2.21 
1.91 
.60 
.04 
11.4 
31 
Orangeburg fine sandy loam, 
Mississippi 
0"-10" 
.03 
.09 
.026 
.00 
1.53 
.57 
.77 
.03 
6.2 
32 
Orangeburg fine sandy loam, 
Mississippi 
10"-36" 
.08 
.03 
.027 
.00 
2.48 
1.13 
.34 
. 03 
21.5 
33 
Sassafras silt loam, Maryland 
0"- 8" 
.15 
.05 
.020 
.00 
2.97 
1.44 
1.45 
.07 
8.0 
34 
Sassafras silt loam, Maryland 
8"-22" 
.21 
.02 
.033 
.00 
3.36 
2.21 
.34 
.03 
18.9 
37 
Stockton clay adobe, California.. 
0"-3S" 
.23 
.06 
.025 
.03 
6.43 
7.74 
1.05 
.02 
43. 1 
38 
Stockton clay adobe, California.. 
38"-50" 
.08 
.05 
.020 
.00 
5.09 
4.47 
.36 
.02 
23.3 
40 
Susquehanna clay, Mississippi. _' 
4"-36" 
.05 
.05 
( 3 ) 
.00 
.00 
8.09 
4.33 
0) 
( 3 ) 
30.4 
42 
Vega Baja clay loam, Porto Rico. 
0"-12" 
( 3 ) 
( 3 ) 
( 3 ) 
12.66 
( 3 ) 
3.64 
( 3 ) 
57.8 
43 
Wabash silt loam, Nebraska 
0"-15" 
.14 
.16 
.031 
.00 
6.40 
2.82 
3.03 
.15 
29.-8 
44 
Wabash silt loam, Nebraska 
15"-36" 
.13 
.06 
.034 
.00 
5.39 
6.34 
2.40 
.11 
32.4 
1 Calculated by multiplying the CO2 evolved by combustion by 0.471. 
2 See Gile (/7) for a discussion of the limitations of this method. 
3 Net determined. 
The analyses given in Table 2 show that the soils selected vary 
sufficiently in the percentages of the major elements to yield colloids 
of varying composition, if such variation exists, and although the 
extremes of composition, especially in calcium carbonate, organic 
matter, and phosphoric acid, are not represented among the soils 
selected, the variations in composition ordinarily encountered are 
covered by these samples. The silica varies from 51.32 to 93.66 per 
cent, the alumina from 2.57 to 22.92 per cent, and the iron from 
0.93 to 13.82 per cent. It is recognized that colloidal m'atter quite 
different in composition from that we have extracted may be sepa- 
rated from peats, pure white clays, and other special soil formations. 
