May s, 1923 
Movement of Soil Moisture upon Freezing 
431 
effect upon the freezing-point depression than that in the finer capillaries 
and around the particles as thin films. 
It can not be definitely stated now which of these two explanations 
is correct. If the latter one is true the position or relative distribution of 
the capillary water as between the finer and larger capillaries affects not 
only the freezing-point depression but also such factors as osmotic pres¬ 
sure, vapor pressure lowering, rate of evaporation, available water, etc. 
Since any treatment of the soil (stirring, breaking up the compound 
particles or crumbs, freezing and thawing, addition of flocculent or de- 
flocculent agents) would alter the position of the capillary water as be¬ 
tween the small and large caj^laries and films, and would have a pro¬ 
nounced effect upon the above factors, their determination could not be 
absolute. Such determinations, for instance, as the vapor-pressure 
lowering of soils as reported recently by Thomas,^ could not be considered 
absolute. If stirring, freezing, etc., affect the freezing-point depres¬ 
sion, they will certainly also affect the vapor pressure lowering. The 
same would be true for several of the other factors. 
SUMMARY 
Evidence is presented which shows that when a soil short of saturation 
is frozen, the force of crystallization tends to draw the moisture from the 
small capillaries and from around the particles as thick films, into the 
larger capillaries. 
However, when the soil is wet or saturated, under proper conditions 
the moisture freezes at the surface of the soil and forms capillary ice 
columns or thin needle-like crystals. The force of crystallization draws 
the water from below, which freezes at the lower end of the column and 
pushes the entire column upward. 
The relative distribution of the capillary water is between the finer 
and the larger capillaries and may have a very appreciable effect upon 
such factors as freezing-point depression, vapor-pressure lowering, 
osmotic pressure, and rate of evaporation. Any treatment of the soil 
which will alter die relative distribution of the soil moisture as between 
the finer and larger capillaries would seem to affect these factors. 
f Thomas, Moyer D. aquhous vapor pressure op soii,s. Jn Soil Sci., v. ii, p. 409^434, $ fig. 1931. 
References, p. 433-434* 
