ere lL 
Natural History of Volcanos and Earthquakes. , we 
last case, in order to exhibit the possibility of hot springs rising in 
the Alps, when water descends from great heights to the interior 
of the rocks, flows through warmer strata of earth, and then 
makes its exit in the valleys. It is clear that such springs merely 
flow from above downwards, when the raised strata make their 
appearance externally, but that they will, on the other hand, rise 
again, if the strata are upraised in the form of a trough on the 
Opposite side. 
Phenomena lately observed, may perhaps present cases, where 
the effect of the internal heat of the earth nearly approaches the 
surface. Marcel de Serres,* for instance, describes a cave near 
Montpellier, situated in the Jura limestone, in which, at depths 
of 135 and 150 feet, a constant temperature of 72°.5 F. prevails, 
Which exceeds by 10° the mean temperature of Montpellier 
(62°.5.) He shows that no accidental circumstance, such as de- 
Compositions, the burning of tapers, or the respiration of those 
Who visit the cave, can be the case of this phenomenon; but 
believes it is to be songht for in: the central heat, which rises 
through clefts and affects one point more, another adjacent one 
less, Thus, at the distance of about 1200 feet from this cave is 
found a cleft in the same formation, from which issue watery va- 
pors, whose temperature, 73°.5 (that of the external air being 
529-549. 5, ) is nearly the same as of an artesian well close in the 
Vicinity of the cave (70°.-72°.) These vapors, which probably 
rise from thermal springs existing beneath, are constantly disen- 
aged, and maintain a temperature of 73°.5, though in constant 
Contact with the external air. The cleft from which they issue, 
communicates with other wider clefts, which expand into caves, 
into which the inhabitants of the estate of Astier have already 
Penetrated. The laborers on this estate are in the habit of 
warming themselves pretty frequently in the hole where these 
Vapors are formed. On examinations, this vapor has all the 
Purity of distilled water. At an earlier period there existed, at 
the distance of 150 to 180 feet N.B. of the grotto of Astier, an- 
other opening from which an equally warm vapor was evolved, 
Which could be perceived at some distance off. This opening 
» however, been since filled up. ‘This constant vaporization 
of water, in the middle of the same rock in which the cave 
BE cee 
* Des Cavernes chaudes des environs de Montpellier in Annal. de Chim. et de 
Phys, t. Ixv, : 
Vol. *xxvu1, No. 1.—July, 1839, bis. 10 
