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346 G E O L O G IC A L P O S I T IO N
At Moutiers, the mica slate, or dark schist,
into which it passes, is not seen at the
spring; but the other side of the valley is
dark schist, and by tracing the calcareous
rock from the ravine in which the hot saline
waters rise, up the valley of the Doron to
Brida, it will be found that the limestone
which covers the hot saline spring, is one
of the lowest beds ; and at Brida, where
the rock has been cut through, to give a
free passage for the warm spring, the excavation
has been made in talcy mica slate ;
while on the opposite side of the river,
where the rock has not been removed, there
is a warm spring, rising from under limestone.
This spring has a lower temperature
than that which rises in the mica slate,
owing, no doubt, to a greater admixture
with the waters near the surface.
The hot springs at Aix have the highest
temperature, and are also the most abundant
of the thermal waters of Savoy, for they
not only forni two considerable streams, but
in the immediate vicinity of Aix, and also
at the distance of one or two miles from
the baths, warm springs issue from the
ground, and only require to be separated
from the surface water, to be of as high a
OF T H E T H E R M A L S P R IN G S . 347
temperature as the springs now in use ; but
the government will not permit other baths
to be opened. The hot springs at Aix rise
at the foot of a calcareous mountain, which
is from 3000 to 4000 feet high. This
might fairly induce the belief, that they
rise near the bottom of this limestone formation
; but a more satisfactory proof may
be obtained, by tracing (as I have done
twice) the range of these mountains in a
south-easterly direction, to where the lowest
beds terminate. The mountain extends
from Aix to near Chamberry, Mont Chaparillon
being a part of the range. Proceeding
to the south-east, the termination
of the limestone may be observed ; its
lowest beds forming on the mountains north
of the Isere, isolated caps, which cease
before reaching L ’Hopital and Conflans,
where the foundation rock is mica slate.
No one who has seen the position of the
baths of Leuk can doubt that the springs
rise near the bottom of the lowest beds of
limestone in that part of the Alps, being
situated in the bottom of an immense
ravine ; and in ascending the valley of the
Bhone, the mica-slate, or dark schist, on