44 
Colorado Experiment Station 
The waters of our mountain streams, as they flow in their moun¬ 
tain sections, are quite similar in composition and carry the following 
salts in solution: Some sulfate, usually calculated as calcic sulfate; 
calcic, magnesic, potassic, and sodic carbonates; some chlorid, usually 
calculated as sodic chlorid, and a relatively large amount of silicic acid. 
The amount of sodic silicate present in such a residue will un¬ 
doubtedly depend upon the amount of aeration to which the water may 
be subjected. If the fall of the stream is heavy and the water has to 
flow over falls and large boulders we will find sodic carbonate instead 
of sodic silicate and the silicic acid will be free or absent, as it may 
have been deposited. If, on the other hand, the water flows over a 
more even bed and the aeration is slight, the sodic silicate may not be 
broken up. We find this to be largely the case in the Rio Grande 
waters, which flow for many miles with an almost unbroken surface 
over material of essentially the same character as the naked rocks of 
the mountains themselves. 
The following analysis will make the difference plain: 
ANALYSIS OF RIO GRANDE WATER 
Percent 
Carbon . 1.661 
Calcic sulfate . 10.203 
Calcic carbonate . 27,620 
Magnesic chlorid . 1.218 
Magnesic carbonate. 2.730 
Magnesic phosphate . 0.351 
Magnesic silicate . 5.220 
Potassic silicate . 4.705 
Sodic silicate . 10.000 
Ferric oxid . 0.645 
Manganic oxid . 0.609 
Silicic acid uncombined. 35.037 
Total . 100.000 
SANITARY ANALYSIS 
Parts per Million 
Total solids .. 77.00000 
Chlorin . 0.00014 
Nitrogen as nitrates . None 
Nitrogen as nitrites . 0.000070 
Saline ammonia . 0.000001 
Albuminoidal ammonia . 0.000002 
This residue was obtained by evaporating the necessary amount 
of water in the field and this is the reason why there is no determin¬ 
ation of the dissolved carbonic acid. The appearance of carbon in the 
analysis is due to the fact that we had to destroy some organic matter 
and we preferred to heat no higher than was necessary to accomplish 
