The Fixation of Nitrogen. 69 
flood, due to the same cause, covered this land to a depth of two 
feet and that it was twenty-four hours before these flood waters 
had entirely disappeared. The flow of these waters, as indicated 
by the straw, weeds and other debris lodged on the posts and fence 
wires, was evidently strong, and the depth assigned, i. e., two feet, 
was probably correct; furthermore it had left very little or no sedi¬ 
ment. I had taken a sample of the mealy surface soil on June 6, 
1910, so I was glad for the opportunity to obtain a sample of the 
surface soil from as nearly the same place as I could locate it from 
memory, on September 25, 1910, not more than thirty-five days 
after the last flood. On this date I dug a second hole to see how 
near to the surface the water plane might be, and as stated before 
it was not within three feet either in June before the floods or in 
September after them, so the drainage of this land must be reason¬ 
ably efficient. I may add that the soil at this place was sandy to 
the depth that I dug, while that of the beet field north of it was 
heavier, inclining to clay. 
ANALYSES 
LXXXV 
LXXXVI 
Water-Soluble 
Water-Soluble 
laboratory 
Laboratory 
No. 956 
No. 1038 
June 6, 1910 
Sept. 25, 1910 
Percent 
Percent 
Calcic sulfate . 
. 7.535 
14.126 
Magnesic sulfate . 
. 12.130 
16.097 
Potassic sulfate . 
. 3.154 
2.777 
Sodic sulfate . 
. 59.793 
58.432 
Sodic chlorid . 
. 13.361 
6.934 
Sodic nitrate . 
. 3.817 
1.296 
Silicic acid . 
. 0.210 
0.338 
100.000 
100.000 
The water-soluble in No. 956, taken in June was equal to 
1 5*35 percent of the air-dried sample, that in 1038, taken in Sep- 
temper equalled 9.533 percent and the nitrates, as sodic nitrate, 
equalled 0.582 and 0.123 percent of the respective samples. It is 
really an accident that we are able to give these data relative to 
the effects of these floodings and while they are far from com¬ 
plete they may serve to give us some idea of what we may expect 
to accomplish by trying to wash the soil, i. e., it will be a much 
more difficult problem in practice than it is in theory. It would 
have been very interesting to have been able to determine the dis¬ 
tribution of the nitrates in this land immediately after the second 
flood and to have determined the rate a which they made their re¬ 
appearance at the surface, for a rapid evaporation must have taken 
place from the surface of this land at this season of the year. One, 
however, would think that the flowing of such a volume of water 
over this land, as occurred on these two occasions, would have ex¬ 
tracted and removed the nitrates rather than to have carried them 
