i 
32 The Colorado Experiment Station 
carry 8,749 parts. The surface section of soil was taken 
to a depth of six inches. This is too deep to get the highest 
amounts of nitric nitrogen and chlorin in parts per million. 
This would undoubtedly have been found within an inch, perhaps 
within the surface one-half-inch, still we find that there is a little 
more than twice as much nitric nitrogen in the top six inches of 
soil as there is in the succeeding 54 inches. The ratio of nitric 
nitrogen to chlorin in the surface six inches of soil is 118.5; in the 
remaining 54 inches it is 1182.5. In the bottom 28 inches of this 
section we find that the soil carries only two parts per million of 
nitric nitrogen and an average of 396.5 p. p. m. of chlorin. The 
ratio of nitric nitrogen to chlorin in this section of the soil, i. e. 
for the bottom 28 inches, is practically 1 :188. On 10 December, 
1911, three sets of samples, each representing the surface nine 
inches, were taken. There were twenty-two samples in each set 
and these were united to form a composite sample. These com¬ 
posite samples show that the surface three inches contained one and 
one-half times as much nitric nitrogen as the succeeding six inches 
and the second three inches contained three times as much nitric 
nitrogen as the third three inches, but the chlorin in the second and 
third three inches was exactly the same. It is in this connection 
that the interesting question of the movement of salts in the soil, 
and to what extent their movement may be affected by the 
capillary movement of the water on the one hand and the 
power of the soil particles to retain the salts on the other hand, 
has presented itself. This soil is a fine, sandy loam underlaid by 
gravel which gives free drainage to the river and is so open that 
the water-plane under this land rises and falls with the rise and 
fall of the river, so that any nitrates that may find their way into 
. the ground-water have direct drainage into the river. 
I have pointed out that in studying the composition of the 
ground-waters we found this to depend quite directly upon the 
height of the water-plane and that we had been convinced that this 
composition came very nearly to representing the soil solutions at 
that level. This statement pertained only to narrow wells. We 
found the waters obtained from newly opened wells growing de¬ 
cidedly poorer in dissolved mineral matter as we attained more 
depth, but I have found no record of any attempt to determine the 
movement of different classes of salts under these conditions nor 
how they mutually modify one another’s movements. 
The soil here considered was all in bad condition; in fact, the 
nitrates had become so abundant as to make the land for the present 
time, at least, useless. There were spots in which this action was 
intense and we find a maximum for the samples given of 1,722 
