28 
The Colorado Experiment Station 
ANALYSIS XXIY. 
RESIDUE FROM SEEPAGE WATER. Laboratory No. 739. 
Per Cent. 
Calcic Sulfate' . 31.102 
Magnesic Sulfate . 2 6.4 87 
Potassic Sulfate . 1.210 
Sodic Sulfate . 21.305 
Sodic Carbonate . 6.101 
Sodic Chlorid . 8.531 
Sodic Nitrate . 4.9 72 
Sodic Silicate . 0.292 
100.000 
The aggregate volume of water issuing from a long stretch of 
this shale is large and according to this analysis each gallon of 
70,000 grains carries 27.75 grains of nitrates. 
In looking for a place to take a sample of shale to see whether 
the shale itself carried nitrates a brick yard offered the best oppor¬ 
tunity for here a face, which had been recently opened, was acces¬ 
sible. The overlying strata are thin but the mesa country above and 
back of this opening is very extensive and quite well watered. It 
was observed that the brick in the drying sheds were covered with 
an efflorescence. This consisted essentially of sodic sulfate about 
88.0 per cent; nitric acid was present but was not determined. A 
sample of the shale 1,280 grams was extracted with water and 
yielded 1.4 per cent of material soluble in water. 
ANALYSIS XXV. 
WATER SOLUBLE PORTION OF SHALE. Laboratory No. 645. 
Per Cent. 
Calcic Sulfate . 32.198 
Magnesic Sulfate . 13.705 
Potassic Sulfate . 1.930 
Sodic Sulfate . 42.990 
Sodic Carbonate . 0.716 
Sodic Chlorid . 2.477 
Sodic Nitrate . 1.711 
Sodic Silicate . 1.081 
Loss (water, organic matter, etc.) . 3.192 
100.000 
The nitrates calculated on the air dried shale gives 0.03 per 
cent. The shale presents but little of interest. The amount of nitric 
acid found is so small that it would escape detection in the 
ordinary course of analysis. Still the analysis of this shale was 
made and shows that there is nothing in the character of the shale 
itself to indicate anything unusual. 
