COLORADO IRRIGATION WATERS AND THEIR CHANGES. 15 
TABLE VI.—SAMPLE TAKEN FROM FAUCET IN CHEMICAL 
LABORATORY, SEPT. 6, 1902. 
Grs. 
Grs. 
Analytical 
Per 
Imp. 
Per 
Imp. 
Results. 
Cent. 
Gal. 
Combined. 
Cent. 
Gal. 
Silicic Acid_ 
. 6.123- 
0.6245 
Calcic Sulfate_ 
31.179 
3.1802 
Sulfuric Acid . . 
. 18.333 
1.8699 
Calcic Carbonate, _, 
30.199 
3.0802 
Carbonic Acid_ 
. 23.266 
2.3731 
Magnesic Carbonate 18.152 
1.8515 
Chlorin_ 
. 1.035 
0.1055 
Strontic Carbonate, 
0.312 
0.0318 
Sodic Oxid .. __ 
_ 6.501 
0.6631 
Potassic Carbonate 
1.338 
0.1364 
Potassic Oxid . 
. 1.883 
0.1921 
Sodic Chlorid _ . 
1.708 
0.1742 
Calcic Oxid... _ 
_ 29.769 
3.0364 
Potassic Silicate, 
1.593 
0.1614 
Strontic Oxid 
0.219 
0.0223 
Sodic Silicate .. , 
11.035 
1.1255 
Magnesic Oxid.. 
8.684 
0.8857 
Ferric and Alu. Oxids 0.168 
0.0171 
Ferric and Alu. Oxids 0.168 
0.0171 
Manganic Oxid 
0.110 
0.0112 
Manganic Oxid_ 
0.110 
0.0112 
Ignition_ 
[4.144] 0.4226 
Ignition . 
[4.144] 
0.4226 
Sum . 
99.938 
Sum 
100.235 
Total 
99.938 10.1921 
Oxygen Equiv. to 
Chlorin 
_ 0.235 
Total 
. 100.000 
10.2235 
Total solids. 10.2 grains per imperial gallon. 
SANITARY ANALYSIS. 
Parts Per Million. 
Total solids _ 145.7143 
Chlorin_ 19.8040 
Nitrogen as Nitrates_ 0.1000 
Nitrogen as Nitrites__ None 
Parts Per Million. 
Saline Ammonia_ 0.1200 
Albuminoidal Ammonia.. 0.0500 
Oxygen required * * * § _ 1.2450 
* Note.—The preceding analyses are expressed in two different units: 
In per cent, and grains per imperial gallon, for ordinary chemical analy¬ 
sis, and parts per million, for the sanitary analysis. I believe that there "is 
no inconvenience caused by this, as the average reader will think of 
3.1802 grains per gallon more readily than of 45.4314 parts per million. 
The term gallon suggests a common measure, as does also the term grain. 
If any one wishes to convert the term grains per imperial gallon into 
parts per million to suit his convenience he has simply to multiply by one 
hundred and divide by seven, which is easily done. 
§ 26. The first three of these analyses represent the water of 
the Cache a la Pondre river as it issues from its mountain section 
without being modified by waters coming from the surface soil or 
from the strata of the jura-triassic or cretaceous formations. In 
order to make our view more general, and to save repetition, we 
will here include the waters of the Boulder and the Clear Creek, 
the analyses of which will be given later. The general similarity 
of the analyses, especially of the analytical results, to those obtained 
by the analysis of the residue obtained by the evaporation of the 
water with which we had treated the felspar, leaves no doubt but 
that the sources of the different residues were the same, and we are 
justified in considering the felspar which occurs abundantly 
throughout the drainage areas the source from which the Pondre, 
the Boulder, and Clear Creek obtain their mineral constituents. 
