Fixation ot Nitrogen in Colorado Soils 
7 
wards sampled the soil and water in a section on this line 2 
miles wide and 8 miles lon^. 
To ^ive the data of this preliminary work would show 
iiotliin^v that cannot be stated in a few words. Starting at our 
eastern limit we found no nitrates in either the soil or water 
samples, till we got within about 3% miles of Wellington, for 
the next 2 or 21/2 miles the nitrates were abundant, but there 
were none in either the waters or soils westward till Ave reached 
ihe region of Dry Creek, just west of Waverly, where they oc- 
curred again, but irregularly and much less abundantly than 
east of Wellington. The AVaverly district did not present suffi- 
cient interest to justify further study at the time. While we 
found some nitrates in this section, the more striking occurrence 
was that of small areas rich in calcic chlorid. These were 
neither large nor numerous enough to be of much interest to 
us as we know of another section, a district in the San Luis 
Valley, in which such areas are larger, more abundant, as rich 
or richer and apparently more difficult to account for than 
these. In the case of these occurrences near Waverly, Larimer 
County, it might be contended that a possible or even probable 
explanation can be found in the history of the section, i.e., as 
there is still a small cattle industry in the section which form- 
erly was predominant throughout the country — these spots 
where the calcic chlorid is now found might be places where 
salt had been put out for the cattle. A successful refutation of 
such an assertion would be difficult even if the assertion is not 
true. While it is easy to show that the reaction between calcic 
sulfate or carbonate and salt may form calcic chlorid, I scarcely 
believe that these areas represent old salting spots. This is not 
the question which concerns us now and we have said, perhaps 
unwisely, more about this than its importance justifies. 
The history of our acquaintance with the occurrences of 
nitrates in the Wellington district, though imperfectly given, 
establishes the fact that the matter is of some importance, and 
that the conditions have persisted long enough to show that 
they are established and are_not temporary as I have known 
them to be in a few cases. The preliminary work or survey of 
the district showed that a single area of 16 square miles is in- 
volved and that there are smaller areas lying outside of this. 
WATER-SOLUBLE SALTS IN SOILS 
We shall give only a few analyses of the water-soluble por- 
tion of these soils as we have published a great many such in 
connection with this general subject, but it is advisable, per 
