Page 96 - 1915, Springs of CA.

92 SPRINGS OF CALIFORNIA.

of hot water. The water is mildly sulphureted but is otherwise only
slightly mineralized, as is shown by the following partial analysis:

Analysis of water from Castle Hot Springs, Lake County, Cal.
[Analyst, Curtis and Tompkins (1909 ?). Authority, advertising matter. Constituents are in parts per
million.]
Properties of reaction:
Primary salinity........................................... Small.
Secondary salinity......................................... Small.
Tertiary salinity............................................ 0
Primary alkalinity.....................................Moderate.
Secondary alkalinity.................................. Dominant.
Tertiary alkalinity ...........................................(?)
Residue:
Combined water.............................................. 19
Soluble in water............................................. 152
Insoluble in water........................................... 175
346
Portion soluble in water:
Sulphate (S04)............................................... 24
Chloride (01).................................................. 6
Carbonate (C08)............................................. 60
Sodium (Na) and potassium (K), chiefly sodium............... 62
Portion insoluble in water:
Silica (Si02)................................................ 113
Calcium (Ca), magnesium (Mg), and carbonate (C03), chiefly
calcium................................................... 62
The analysis indicates a secondary alkaline, primary alkaline water
in which silica is present in relatively large proportion.
The position of these hot springs high on the mountain side is
worthy of note, and it is also of geologic interest with respect to the
hot springs at Anderson Springs, a mile eastward and 800 feet lower,
and at The Geysers, a few miles northwestward across the range and
1,000 feet lower. In another ravine, about 700 yards by path from
Castle Hot Springs, but perhaps half that distance in a direct line and
100 feet lower two groups of cool sulphur springs seep from the banks.
The rock near the hot springs consists of hard schistose material that
is not greatly decomposed, but near the cool springs it has been
altered, apparently by solfataric action, and is impregnated with
sulphur and sulphate salts.
The property was formerly known as Mills Hot Springs and was at
one time conducted as a small resort, the hot water being used for
bathing and the water -of the cool sulphur springs for drinking. In
the summer of 1910 the property had recently changed ownership
and was being reimproved as a resort. A hotel, a bathhouse con-
taining a swimming plunge, and a dancing pavilion were being erected,
and several tent cottages provided accommodations for a few guests.