8 
The Colorado Experiment Station 
plane rose, in this case very nearly to the surface, the salts 
that went into solution increased. The nitrates were near or 
at the surface of the soil, as is clearly shown by the air-dried 
samples already given. The fact is that in this section of the land 
they were very abundant. The ratio of the nitric nitrogen to the 
chlorin in this water was i .*3.63. The ground-water at the bottom 
of this well, that is the water underlying this section, contained an 
exceedingly small quantity of nitric nitrogen and the drain-waters, 
i. e. the ground-waters that were coming into this section, gave 
0.24 and 0.48 parts per million for two different drains, and cannot 
justly be considered the source of the nitrates found at the surface. 
I have given the data for this case for the reason that the land was 
very rich in alkali, and affords us, I believe, reliable information 
relative to the probabilities that the nitrates discussed in Bulletin 
1 55 an d 178 may owe their origin to a process of concentration 
of ground-water rising through the soil, or filtering in from adja¬ 
cent lands; in other words, of their having a common origin with 
the alkalis. We see in these samples of soil and ground-water only 
moderate quantities of nitrates, from a trace to thirty-six parts per 
million, in the soil, while in the well-waters it varies from a trace 
THESE WELL-WATERS GAVE THE FOLLOWING RESULTS : 
Well No. 1. 
Well No. 2. 
Well No. 3. 
Total Solids 
Chlorin 
Nitrie N 
. 10,357.0 
971.4 
3.6 
7,590.0 
689.3 
6.0 
8,387.0 
792.9 
3.4 
10,312.0 
962.1 
3.3 
9,831.4 
895.4 
3.1 
6,215.7 
556.4 
2.2 
6,461.4 
525.0 
1.9 
2,705.7 
162.3 
1.9 
2,388.5 
165.0 
1.7 
2,164.3 
107.0 
1.6 
1,990.0 
105.0 
1.9 
1,882.8 
85.7 
0.4 
1,752.8 
80.5 
0.4 
7,297.0 
578.0 
28.0 
7,478.5 
595.0 
27.2 
6,821.4 
522.9 
26.0 
6,711.4 
521.4 
22.8 
6,717.1 
571.0 
9.2 
7,442.0 
602.9 
9.2 
7,561.3 
610.0 
8.2 
7,778.5 
612.9 
8.4 
5,564.3 
503.6 
28.0 
5,378.5 
385.7 
16.0 
8,492.8 
397.1 
16.0 
5,514.3 
398.5 
12.0 
1,600.0 
68.0 
Trace 
7,863.0 
384.7 
106.0 
5,385.7 
240.8 
54.0 
3,928.6 
121.0 
20.0 
