Page 183 - 1915, Springs of CA.

CARBONATED SPRINGS. 167

Besides its use on the grounds for drinking the water has been
bottled and sold locally.
The rocks exposed along the canyon are crushed and altered sand-
stones and shales, with a little cherty material, the springs issuing
from sandstone.
DTJNCAN SPRINGS (MENDOCINO 31).

Duncan Springs are situated 2 miles west of south from Hopland,
on slopes that overlook Russian River valley. The property has been
run as a resort since the eighties. Several additional buildings have-
been erected during recent years, so that in 1909 a hotel, annex, and
several cottages provided rooms for about 100 guests.
There are two principal springs, which are known as Magnesia
Spring and Soda Spring, and two minor slightly used springs. The
Magnesia Spring issues at the eastern end of a pavilion 175 yards
south of the hotel. Two cemented basins have been constructed in this
place on a sloping surface of serpentine. Their combined yield is
perhaps one-half gallon per minute of water that is moderately
carbonated and magnesic in taste. This water has for a number of
years been shipped to San Francisco and carbonated and bottled for
table use. The analysis (p. 168) shows that it is essentially a magnesic
alkaline water. The unusually small content of sodium reported is a
remarkable feature of the analysis.
The Soda Spring is higher up the slope, in a ravine 500 yards to the
southwest. Like the Magnesia Spring, it also issues from serpentine
and is protected by a rock-walled basin. Its water is strongly car-
bonated and tastes distinctly of iron, and considerable iron is also
deposited in the spring and along its overflow channel. This constit-
uent renders the water unsuitable for bottling and sale, as it stains
the bottles, but the water is used on the grounds for drinking and is
also piped to a bathhouse near the hotel and heated for bathing.
The following analyses of the water show noteworthy differences
in the character of the two springs, the Soda Spring possessing both
primary and secondary alkalinity, whereas the Magnesia Spring has
no reported primary alkalinity but high secondary and tertiary
alkalinity.