428 
Journal of Agricultural Research 
Vol.;XXIV, No. 5 
Tabi,E I. —Effect of alternate freezingy thawing, stirring, and standing on the freezing- 
point depression of soils 
WISCONSIN SUPERIOR CI<AY (20 GM. SOU. AND 4.5 CC. WATER). 
Treatment. 
Breezing- 
point 
depression. 
First freezing.... 
"C. 
I.I15 
•955 
.645 
.620 
Second freezmg. 
Third freezing..... 
Fourth freezing. 
Stirred gently m tube with rod... 
1.215 
.680 
Cooled at —10® C. after stirring. 
Stirred gently in tube with rod..*.. 
1.215 
^700 
.787 
.701 
Cooled at —10® C, after stirring ..... 
After standing one day in room temperature.. i.................. 
Cooled at — lo® C ........ 
MICHIGAN SILT LOAM (20 GM. SOIL AND 3 CC. WATER). 
I^rst freezing..... 
0.880 
Cooled at — lo® C. . .. 
.460 
.790 
.3^ 
. 7 »S 
.420 
.600 
Stirred gently in tube with rod. 
Kept at —10® for several hours after stirring... 
Stirred gently in tube with rod.... 
Cooled at —TO® C- after stirring ... 
Stood in room temperature after the last reading for 10 days. 
Cooled at —10® C. 
.3^ 
BI.ACK CI,AY LOAM (20 GM. SOIL AND 4 CC. WATER). 
First freezing..... 
Cooled at — lo®—. 
Cooled at —10® for several hours.... 
Stood two days at room temperature 
Cooled at — lo®.. 
Stirred gently in tube with rod. 
Cooled at — lo® after stirring. 
Stirred gently in tube with rod.. 
0.760 
.400 
.270 
•430 
.322 
.760 
• 450 
•765 
An examination of the results indicated in Table I shows the great in* 
fluence that different treatments have upon the freezing-point depression 
of soils at low moisture contents. In the case of the Wisconsin superior 
clay, for instance, the freezing-point lowering diminished by alternate freez¬ 
ing and thawing from 1.115° to 0.620° C. at the fourth freezing. Upon 
stirring the soil mass with a rod in the tube, the freezing-point depression 
increased from o.620° to 1.215°. When the soil was kept at a temperature 
of -10° for few minutes the depression fell from 1.215° fo 0.680°. As the 
soil was stirred again the depression rose from 0.680 to i .215 as before. By 
leaving the soil to stand for one day at room temperature, ^ter the depres¬ 
sion was diminished by repeated freezing, the depression rose from 0.700° 
to 0.787°. It will be noted that in some cases stirring increases the freez¬ 
ing-point depression even to more than the original extent. 
