APPENDIX, 



ON THE THERMAL WATERS OF THE ALPS. . 



This paper was published by the Author in the " Philosophical 

 Magazine and Annals," January 1827; and a nearly similar account 

 was given in his " Travels in the Tarentaise," in 1823. T'he ther- 

 mal v/aters of the Alps had before been regarded as merely local and 

 unconnected phenomena, scarcely deserving the no.ice of geologists. 



When we approacn & range of lofty mountains, like that of the Pen- 

 nine Alps, and observe the calcareous strata on the outer part of the 

 range, bent and contorted :p various directions ; when we further ob- 

 serve beds of limestone and pudding-stone alternating and placed in 

 an elevated position, as we eiivance to the central part of the range ; 

 and that the beds of granite in the central part are frequently verti- 

 cal ; we feel assured that their present contorted or vertical position, 

 is not the original one. The opinions of geologists have been much 

 divided respecting the cause or causes that have elevated mountains, 

 and given a vertical position to beds that once formed the bottom of 

 the ocean. Those who maintain that subterranean heat has expanded 

 and broken the solid crust of the globe, and has raised from vast 

 depths the ancient bed of the ocean, appeal to a cause that is known 

 to exist, and which seem sufficient to explain most of the various ap- 

 pearances which Alpine regions present. 



In opposition to this theory, it is asserted that there are no remain- 

 ing vestiges of the action of subterranean fire in the Alps : but this I 

 am convinced is erroneous. It is true that from near the source of 

 the Rhone, to the foot of the Little St. Bernard, there does not occur 

 any known rock of a volcanic character, with the doubtful exception 

 of some rocks in the valley of Sass, and in the Valorsine. I have ex- 

 amined various parts of this range on the northern side of the highest 

 mountains in the Alps, along a line of one hundred and twenty miles ; 

 and though I could discover no indications of the action of subterra- 

 nean heat in the rocks themselves, I was greatly surprised to observe 

 the numerous thermal springs that are abundantly gushing out at the 

 feet of the primary mountains, near the junction of the mica-slate, or 

 the dark schist passing into the mica-slate, with the lowest calcareous 

 beds of that vast series of limestone strata, which forms the outer ran- 

 ges of the Alps. Numerous as these hot springs are on the northern 

 side of the Alps, and not unfrequent on the southern side also, it ap- 

 peared to me remarkable, that they had hitherto been regarded as iso- 

 lated phenomena ; and that their geological position had not been no- 

 ticed. It is true, some of the warm springs in the Valais and in Sa- 

 voy had been long known and visited. But the greater number has 

 been discovered since Saussure published hisVoyages daiisles Alpes ; 

 and it appears probable, that they would every where be found near 

 the junction of the primary and secondary rocks, were it not for 

 ehoulements that have covered them with a heap of ruins, or that tor- 

 rents from the glaciers have mixed with them, and reduced their tem- 

 perature. Since I visited Savoy in 1821 and 1822, another considera- 

 ble warm spring has been discovered near the village of Chamouni, at 

 the foot of a glacier ; and in 1820 several thermal springs were discov- 

 ered in that branch of the Alps which extends to Grenoble. 



