The Soil. 
23 
the fali of the water plane in this plot took place at the rate of one 
foot in thirty days. I would have assumed this to be the rate of 
drainage out of this area, had we not demonstrated, much against 
our will at the time, that there is a flow of water from the west into 
our plot, and the fall of one foot in thirty days is simply the excess 
of the drainage out of the area over that into it. 
DEPORTMENT OF SOIL WITH WATER SHRINKAGE INCLUDED. 
§ 47. I have stated twice that one characteristic of this soil is 
its retentiveness of moisture. I do not mean by this statement that 
it will refuse to give up a larger percentage of moisture than other 
soils, when exposed to drying out in the air or subjected to drought, 
but that excessive water is given up slowly, and also that when it 
dries it shrinks and becomes very hard, which is true of many soils 
in this State. 
§ 48. I made two experiments to determine the rate at which 
this soil dries after being saturated with water, and also to deter¬ 
mine the loss of volume due to shrinkage. 
These samples deported themselves very differently. The 
sample of soil A, placed in a cylindrical box, showed 
moisture on the surface in seven minutes after the perforated bottom 
of the box was placed in water, but the soil had not become satu¬ 
rated at the expiration of four and one-ouarter hours, and was per¬ 
mitted to stand in contact with the water over night. The sample 
of soil D, on the other hand, did not show moisture on the surface 
until forty-five minutes after it was placed in contact with the water, 
but was saturated in one and one-quarter hours. • Soil A required 
for saturation 18.18 grams of water, and lost in eleven days 17.78 
grams; D required 16.62 grams for saturation, and gave up 16.20 
grams in eleven days. The shrinkage was the same in both cases, 
28 per cent, of the original volume. The cylinders were filled and 
shaken down to make the soil compact. The loss for each twenty- 
four hours, up to the end of the seventh day, is given in the follow¬ 
ing table, together with that for pulverized feldspar, which was used 
for the sake of comparison. The feldspar had been pulverized so that 
its particles approached those of the soil as nearly as possible in size. 
The volumes were the same. It will be born in mind that the soil 
contains humus, clay, salts, etc., while the feldspar does not. The 
feldspar showed moisture in one minute after being placed in the 
water. One sample was saturated in ten and the other in twenty 
minutes. This is a very pronounced difference, the soils requiring 
75 and upwards of 255 minutes for their saturation. The feldspars 
required for saturation 8.94 and 7.39 grams of water respectively, 
the soils, 18.18 and 16.60 grams. 
