ESTIMATION OF COLLOIDAL MATERIAL IX SOILS. 11 
Table 1. — Adsorvtion of malachite green, water, and ammonia by soils and soil colloids. 
Type of soil or colloidal marc-rial. 
Adsorbed per gram of soil. 
Adsorbed 
per gram of coUoidal 
material. 
Dye. 
H 2 0. 
NH 3 . 
Dye. 
H 2 0. 
Nil . 
-Ton loam: 
Soi 1 
Gram. 
0. 0531 
.0504 
.0078 
.0402 
.0148 
.0239 
.0353 
.0506 
. 0213 
.0314 
.0236 
.0182 
.0188 
.0223 
.0782 
.1049 
.0322 
.1148 
.0167 
.0275 
.0312 
.0231 
.0084 
.0268 
.0271 
.0289 
.2128 
.2075 
.0644 
.0369 
.1088 
.1050 
Gram . 
0.1005 
.0978 
.0341 
.0903 
. 0203 
.0676 
. 0789 
.0804 
.0434 
.0857 
.0632 
.0604 
. 0520 
.0632 
.0803 
.1030 
. 0685 
.1540 
.0261 
.0565 
.0424 
.0365 
.0164 
. 0655 
.0212 
.0586 
.1886 
.1471 
.07a5 
.1805 
.0990 
.1002 
Gram . 
0. 0168 
.0170 
.0034 
.0050 
.0049 
.0087 
.0077 
.0106 
.0066 
.0089 
.0104 
.0083 
.0064 
.0057 
.0180 
.0212 
.0103 
. 0194 
.0055 
. 0055 
.0070 
.0064 
.0025 
.0059 
.0047 
.0074 
.0358 
.0320 
.0189 
.0147 
.0212 
.0207 
Gram. 
0. 2744 
.3210 
.0770 
. 1582 
.1348 
.1392 
.1424 
. 2154 
. 1584 
.1704 
. 1750 
. 1538 
.1640 
.1838 
.2978 
.3076 
.2134 
.2096 
.1464 
.1158 
.1968 
.1932 
.1138 
.1624 
.1996 
.2188 
. 3757 
.4128 
. 4308 
. 05S4 
.3698 
.3866 
Gram. 
0. 3102 
.3327 
.3359 
.2870 
.2398 
.2723 
.3390 
.3147 
.2592 
.2675 
.2739 
. 2903 
.2822 
.3402 
.2940 
.3000 
.3020 
.3075 
.2430 
.2755 
.2289 
.3203 
.2630 
.3045 
. 2659 
.3097 
.3080 
.3410 
. 3365 
.•3125 
. 3325 
.3090 
Gram. 
0. 0523 
.0665 
lay loam: 
Soil ." 
Subsoil 
Chester loam: 
Soil... 
.023 
. 0192 
.0293 
. 0256 
ClarksvUle silt loam: 
Soil 
Subsoil 
.0359 
.0408 
Hagerstown loam: 
Soil 
Subsoil 
Huuuneton loam: 
Soil 
Subsoil 
Manor loam: 
Soil 
Subsoil 
Marshall silt loam: 
SoU '. 
.0278 
.0299 
.0319 
.0274 
.0308 
.0264 
.0536 
.0568 
Miami <iltv clav loam: 
Soil 
.0411 
. 0358 
Norfolk fine sandy loam: 
-•oil .' 
.0303 
Subsdil 
Ontario loam: 
soil * 
.0295 
.0379 
.0387 
Orangt burg fine sandy loam: 
Soil ' • 
.0411 
Subsoil 
.0363 
Sassafras silt loam: 
SoU 
.0329 
Subsoil ■ 
.0340 
.0609 
Stockton clay adobe: 
Soil 
.0617 
SubsoU 
Vega Baja clay loam, soU 
Wabash sUt loam: 
Soil 
Subsoil 
. 0560 
.0206 
.0314 
.0544 
The adsorptive capacities of the different soils for all three sub- 
stances — malachite green, water, and ammonia — varied greatly. 
This was to be expected, since the adsorption of the soil is condi- 
tioned by the kind of colloidal matter as well as by the quantity 
present. 
The adsorptive capacities of the samples of colloidal matter ex- 
tracted from the different soils are of considerable interest. The 
following facts seem especially significant : There are wide variations 
in the adsorptive capacities of the different colloidal materials for 
malachite green and for ammonia, but the adsorptive capacities of 
the different colloids for water vapor are more nearly constant. The 
highest and lowest values for malachite green are 0.4308 and 0.0584; 
the extremes for ammonia are 0.0665 and 0.0192; whereas the ex- 
tremes for water are 0.3410 and 0.2289. The relative constancy of 
the adsorptive capacities of the different colloidal materials" for 
water vapor suggested the possibility of obtaining an indication of 
the colloidal content of soils by merely dividing the water adsorptive 
