I 
Dec. 10,1917 Movement of Soluble Salts through Soils 535 
in diameter were used. As illustrated by figure 1, each of the brass 
containers was made up of three sections, the short central portions 
being 2 inches and each of the longer ones 8 inches in length. In setting 
up the series the short tubes were filled with the soil which had been 
treated with a definite amount of salt, the longer tubes joined to them, 
and then carefully filled with the moist untreated soil. The water 
content of the entire soil column was as nearly uniform throughout as 
could be made by careful mixing and screening. After the tubes were 
filled they were carefully sealed, unless otherwise t specified, and then 
placed in a closed chamber, the temperature of which was maintained 
constant at 18 0 C. At the close of each period the tubes were unsealed; 
cross sections of the soil were removed by means of a spatula, dried, 
cooled in a desiccator, and carefully mixed; then the freezing-point 
lowering was determined in the usual manner. 
MOVEMENT OF SOLUBLE SALTS THROUGH FINE-TEXTURED SOILS* 
In the first series of experiments the changes induced in the concen¬ 
tration of a rather heavy silt-loam-soil solution by the addition of sodium 
chlorid were studied. Water to the extent of 50 per cent of the oven- 
dry weight of the soil was added when the depressions of the freezing- 
point lowerings were determined. The results presented in Table I 
are quite striking, changes in the concentration of the soil solution 
being measurable 3 inches from the soil mass treated with 1 per cent 
sodium chlorid in solution, after seven days, and 2 inches from that 
receiving o. 1 of 1 percent of the salt solution. Fifteen days after the 
treatment it is worthy to note that the concentration of the soil solution 
showed an increase throughout the tubes which had been treated with 
the larger amounts of sodium chlorid; but, on the other hand, changes 
induced in the soil which had received a more dilute salt solution were 
less striking. Under the above conditions the rate of salt movement 
becomes more rapid with an increase in the mass of salt added to the soil. 
Table I .—Changes in the concentration of the soil solution induced by the addition of 
sodium chlorid to a heavy silt loam 
Freezing-point lowerings. 
Freezing-point lowerings. 
Distance from 
After 7 days. 
After 15 days. 
Distance from 
After s days. 
After rs days. 
salt layer. 
salt layer. 
r per 
0.1 per 
1 per 
0.1 per 
1 per 
0.1 per 
1 per 
0.1 per 
cent 
cent 
cent 
cent 
cent 
cent 
cent 
cent 
NaCl. 
NaCl. 
NaCl. 
NaCl. 
NaCl. 
NaCl. 
NaCl. 
NaCl. 
Inches. 
Inches. 
A . 
0. 000 
0 . OOO 
O.025 
O. 000 
I . 
O. 100 
O. 012 
O. 075 
0. 013 
7 . 
.003 
. 000 
. 040 
. 000 
2. 
•045 
.050 
, 005 
O 
2 . 
•045 
. 006 
. 080 
. OIO 
.003 
. OOO 
•035 
. 000 
1 . 
. 105 
. OIO 
. 090 
. 020 
A . . 
. OOO 
. OOO 
. 020 
. 000 
■. 
0 .i 
. Il6 
.015 
•095 
. OIO 
