Volcanos and EartJiqunkes. 567 



examples in very different parts of the chain, one at the Eaux 

 Bonnes^ where a perfectly cold spring rises within two hun- 

 dred yards of the principal hot spring of the place, has similar 

 medicinal properties, and is even more strongly impregnated 

 witli sulphur. The other example occurs at Las Escaldas^ on 

 the southern declivity of the Eastern Pyrentes^ where a most 

 efficacious cold sulphureous spring rises within about one hun- 

 dred yards of a hot one. When, Forbes continues, to these 

 facts we add others scarcely less curious, of springs of totally 

 different mineral composition issuing from nearly the same 

 spot, and with temperatures from 160° to 180° Fahr., as we 

 see at Ax and at Thuez^ we are forced to conclude that the 

 source of mineralization must be independent, to a great extent, 

 of that of high temperature, and that the arguments, as to the 

 origin of thermal springs founded upon their chemical compo- 

 sition, must be to a certain degree fallacious. 



The origin of the sulphureous waters in the Pyrenees can 

 scarcely be sought for in the granite, since no substances are 

 contained 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, as 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 residt, according as warm or cold water penetrates to tjiis 

 point. The granite plays, then, no other part here, than that of 

 rendering possible the descent of meteoric water to great 

 depths, and its re-ascent in consequence of the raising of the 



• See my memoir in the Neues Jahrhueh der Chemie und Phys. t. vi. p. 251, 

 year 1832. The proportionally large quantity of organic matter in the Ptf 

 rencan sulphureous springs (among which that of Bar^gine, so called from 

 the valley of Bareges, is remarkable) speaks but little in favour of their ori- 

 gin from a mountain produced by volcanic fire. 



