Feb. s, 1917 
Measurement of Inactive Moisture in Soil 
209 
Table VII .—Effect of degree of water content present upon the amount of water that fails 
to freeze 
Name of soil. 
Quantity of 
water fail¬ 
ing to freeze 
when 5 c. c. 
of water 
were added. 
Quantity of 
water fail¬ 
ing to freeze 
when 10 c. c. 
of water 
were added. 
Quartz sand. 
C. c. 
0.10 
•30 
2. 00 
3.10 
3 - 7 ° 
3 * 50 
2. 80 
4. 00 
C. c. 
0.10 
.40 
1. 00 
1. 60 
2. 30 
2. 50 
2.60 
2. 20 
2. 80 
Sand. 
Sandy loam... 
Silt loam. '' ... 
Heavy silt loam. 
Do. 
Do. 
Do. 
Clay. 
There are two columns of data in Table VII, one showing the amount 
of water that failed to freeze when 5 c. c. of water were added to 25 gm. 
of soil and the other when 10 c. c. of water were added to the same 
quantity of soil. An examination of the results in these two columns 
shows at once that actually a greater amount of water failed to freeze 
when 5 c. c. of water were added than when 10 c. c. were added. This is 
true, however, only in the case of the complex colloidal types of soil and 
not in the simple noncolloidal types. Thus, in the case of one of the heavy 
silt loams the amount of water that failed to freeze when 5 c. c. were 
added is 3.5 c. c., while the amount that failed to freeze when 10 c. c. 
were added is 2.6, or a difference of 0.9 c. c. It will be observed that in 
almost every soil of the complex colloidal classes, about 1 c. c. more 
water failed to freeze when 5 c. c. were added than when 10 c. c. were 
added. In the case of the simple noncolloidal classes of soil, such as 
the sands, that quantity of water that failed to freeze was the same in 
both the smaller and larger quantity of water added. 
The foregoing data in the case of the colloidal soils are really very 
significant. They indicate that the absolute amount of inactive or 
unfree water is greater at low moisture content than at high. Evidently 
an excess of water diminishes the quantity of water that the colloidal 
soils cause to become inactive or unfree. 
Just why the quantity of water that fails to freeze in the colloidal soils 
is greater at the low moisture content than at the high can not be ex¬ 
plained at this time definitely. The following suggestion, however, may 
be offered: It is probably partly due to the fact that the total force of 
solidification is greater at the higher moisture content than at the lower, 
and consequently more water is freed or extracted from the soil in the 
former than in the latter. In short, the rdle of the relative masses 
present comes into play. 
