sS The Colorado Experiment Station. 
ANALYSES LXXI 
Water-Soluble 
laboratory 
No. 837 
Sept. 22, 1909 
Percent 
Calcic sulfate . 1.086 
Calcic chloric! ... 
Magnesic sulfate . 20.124 
Magnesic chlorid .. 
Magnesic nitrate .. 
Potassic sulfate. 1.404 
Potassic chlorid .. 
Potassic nitrate .. 
Sodic sulfate . 14.854 
Sodic chlorid . 26.067 
Sodic nitrate . 36.078 
Iron and Aluminic oxid . . . . 0.285 
Silicic acid . 0.102 
LXXII 
LXXI 11 
LXXIV 
Water-Soluble 
laboratory 
No. 839 
.Sept. 22, 1909 
Water-Soluble Water-Soluble 
laboratory laboratory 
No. 841 No. 842 
Sept. 22, 1909 Sept. 22, 1909 
Percent 
Percent 
Percent 
41.538 
3.676 
12.503 
23.624 
8.719 
28.047 
9.802 
3.655 
20.699 
2.952 
20.522 
2.369 
4.899 
4.021 
1.589 
40.258 
0.452 
0.317 
33.820 
0.323 
0.397 
35.077 
0.247 
0.415 
100.000 100.000 100.000 100.000 
The location of this land is such that we cannot account for 
the presence of the large amount of nitrates by supposing them to 
have been brought into the area by surface waters and scarcely by 
underground flows. The seepage in this case is probably largely due 
to leakage from an irrigating ditch and in some measure to the 
excessive use of water by a neighbor, but the acreage from which 
such water might come is too small to account for the conditions 
as we find them. This land, like the most of our lands, contains 
the so-called alkalis. 
Case No. 21 —This is the same as No. 4 given in Bulletin 
i 55 > P a §' e 18. The reason for mentioning it is that it presents 
conditions which contrast quite strongly with the last instances 
given under the captions of Nos. 19 and 20. This piece of ground 
has been so dry every time that I have visited it, that it has seemed 
impossible that the nitrates should develop if I am correct that 
there is a minimum quantity of water necessary for its most rapid 
development, and that this minimum is rather high. Without hav¬ 
ing made any experiments to determine this amount I would judge 
it, according to my observations, to be above 18 percent of the 
weight of the soil. The bacteria can, without doubt, survive long 
and pretty thorough drying, and if a favorable degree of moisture 
be supplied at any time they are ready to develop. Whether they 
be able to endure greater changes in conditions than other kinds 
of bacteria or not is a question that I know nothing about, but 
unless I am greatly in error in the whole matter, the conditions in 
the present case become of considerable interest in this discussion. 
In discussing Nos. 19 and 20, as well as in my statement of the 
general proposition, I have connected it so closely with that of 
seepage that some may infer, as I know that some have already 
