60 Natural History of Volcanos and Earthquakes. 
‘same spot, and with temperatures from 160° to 180° Fahr., as we 
see at Arand at Thuez, we are forced to conclude that the 
source of mineralization must be independent, to a great extent, 
of that high temperature, and that the arguments, as to the origin 
of thermal springs founded upon their chemical composition, 
must be to a certain degree fallacious. 
The origin of the sulphureous waters in the Pyrenées can 
scarcely be sought for in the granite, since no substances are con- 
tained in it which can be supposed to produce such springs. If 
such springs are formed by the decomposition of sulphates by 
means of substances containing carbon, it is very probable,* then 
we must look for the origin of the Pyrenean sulphureous waters 
in the secondary formations, perhaps in some coal stratum, or 
even possibly in the tertiary formations. This inference holds, 
even if the sulphureous springs are formed in a manner opposite 
to this view. If, now, the origin of the springs in question, in 
other words, if the materials necessary for their formation be 
present in one of the newer parts of the secondary formations, 
then warm or cold sulphureous springs will result, according as 
warm or cold water penetrates to this point. The granite plays, 
then, no other part here, than that of rendering possible the de- 
scent of meteoric water to great depths, and its re-ascent in con- 
sequence of the raising of the strata effected by the granite, 
which circumstance causes the heating of these waters. 
In this point, I think both theories agree ; viz., that which at- 
tributes the heat of springs to chemical processes, and that which 
refers its origin to central heat : for those who hold the former opin- 
ion will doubtless not assign the stratified formations as the seat 
of these chemical actions, but the granite, or the parts beneath 
it. According to both theories, then, the meteoric water will be- 
come warmer in proportion as it approaches nearer to the source 
of heat, which can be sought for only at great depths. 
As the subterraneous course of springs is subjected to many 
kinds of local impediments, so veins of springs of similar origit 
may flow out at points very remote one from another; and, vice 
by volcanic fire. 
