Feb. s, 1917 
Measurement of Inactive Moisture in Soil 
211 
was not free or active to act as a solvent but was removed from the 
liquid phase and consequently also from the field of action, so far as the 
freezing-point lowering is concerned. Under this assumption the results 
could be easily explained. Thus, for example, if a clay caused 15 per 
cent of water to become inactive or unfree, either physically or chemically, 
or both, and at 39 per cent of moisture this clay gave a depression of 
0.075° C., and at 22 per cent, 0.987°, then in the first case there was 
24 per cent of free and active water to dissolve the salts and take part in 
the freezing-point lowering, while in the second case there was only 
7 per cent of free and active water for the same purpose. The depression 
of the freezing point at the low moisture content therefore would be 
many times greater than that at the high, than would be expected from 
the total percentage of moisture content, 
(2) It was also found in these researches on the freezing-point lowering 
of soils that the magnitude of the depression decreased with successive 
freezings. This was true, however, only in the complex and colloidal 
types of soil such as the silts, loams, clay loams, and clays, and not in 
the simple and noncolloidal types such as the quartz sand, sands, and 
light sandy loams. 
In explanation of this phenomenon the hypothesis was offered that a 
large portion of water which was made unfree or inactive and thus 
removed from the liquid phase was due to the colloids which the soils 
contained. This unfree or inactive water existed in the colloids both 
as physically adsorbed and loosely chemically combined. Upon freez¬ 
ing, these colloids coagulated and the bonds uniting them with the water 
broke and the combined or unfree water became liberated and free. 
This liberated and free water went to dilute the original soil solution 
and thus decreased the lowering of the freezing point. Thus, for instance, 
if there were 5 per cent of free water at the beginning of the first freezing, 
there were probably 7 per cent at the end of the first freezing, 7.5 per 
cent at the end of the second freezing, and so on until all the colloids 
were coagulated. 
It might appear that the foregoing data do not prove that the unfree 
water exists as physically adsorbed and loosely chemically combine^ 
and probably in the solid phase. It could also exist as capillary and 
film water in the liquid phase. If it is in the liquid phase, why does it 
not take part in dissolving the salts like the free Water does, and be in 
equilibrium with the latter, so that the freezing-point lowering would 
not follow such an abnormal course ? 
(3) The view that some of the unfree water in the soil may exist as 
physically adsorbed and loosely chemically combined probably in the 
solid phase is considerably strengthened by the results obtained by 
Jones (6, p. 238) on the freezing-point lowering of hydrates. Jones 
found that the different hydrates such as calcium chlorid, magnesium 
