The Fixation of Nitrogen in Colorado Soils 29 
DISTRIBUTION OF SALTS IN 40-INCH COLUMN OF SOIL BY THE ASCENTION 
OF DISTILLED WATER DUE TO CAPILLARITY. 
Top 5 inches . 
Nitrogen as 
Nitrates 
Percent 
Chlorin 
Percent 
0 1 70 
Total 
Nitrogen 
Percent 
O OOI90 
Second 5 inches . 
O p;7Q 
O 0«p;98 
Third 5 inches . 
O 3*4. 
O 0*Q4_Q 
Fourth 5 inches . 
0 001 
O 0*04.4. 
Fifth 5 inches . 
0 034. 
o o**oq 
Sixth 5 inches . 
0.029 
0.043 
0.028 
v.UOOuO 
o o^^os 
Seventh 5 inches . 
O 0*04.4. 
Eighth 5 inches . 
0.05780 
The distilled water in the vessel was about a litre in volume, 
and it contained small amounts of nitrates and chlorids at the end 
of the experiment. The amounts of chlorin and nitric nitrogen 
in the soil, as put into the tube, were respectively 0.1578 and 
0.00164 percent, and the total nitrogen 0.05168 percent. The soil 
was thoroughly mixed so that it was perfectly uniform in com¬ 
position when put into the tubes. The lower portion of the soil 
column, i. e. the bottom ten inches, was entirely freed from its 
nitrates; this may have been due to washing out of the nitrates as 
well as due to upward movement .in obedience to capillarity. The 
presence of nitrates in the distilled water at the end of the experi¬ 
ment indicates that there was an actual passage of the nitrates from 
the soil into the water. A third possible explanation for the dis¬ 
appearance of the nitrates might be their reduction, we have not 
considered this at all, and have paid no attention to the nitrites nor 
to the ammonia present in either the water or the soil. The duration 
of these experiments was only thirty days, too short a time, but 
it was not practical to continue them longer. The water attained 
a height of thirty-five inches in the case given. We observe that 
the five inches of soil marking the upper limit of moisture, shows 
an increase of nitrates, but this increase is insignificant compared 
with the increase of the chlorin. The original soil carried 16.4 p. p. 
m., this five-inch section carried 24 p. p. m., but the next five-inch 
section above this, carried only 12.0 p. p. m. As our results stand 
they indicate that the movement of the nitrates is probably very 
far from simple, and where the differences, i. e. gains over the 
amounts originally present, are so small that they fall below the 
values found for the nitrifying efficiency of our soils in the same 
time, it is wholly unsafe to draw even tentative conclusions. These 
statements are not to be applied to the chlorin for we find a 
very decided upward movement of this element. In the original 
soil as placed in the tube we find 1,578 p. p. m. but in the five 
inches of the column, containing the limit to which the moisture 
