THERMAL WATERS OF THE ALPS. 



69 



The quantity of water which issues from these springs is very consid- 

 erable ; and the thawing of the bottom of the glaciers during intense 

 frost may, I believe be attributed to the action of thermal waters. 

 On the Italian side of the same range of Alps, particularly at St. 

 Didier, near the steep southern escarpment of Mont Blanc, there are 

 several thermal waters ; and further west than the hot springs at Aix, 

 in Savoy, other hot springs have been recently discovered near Gre- 

 noble. It thus seems probable that there still exists, under this range 

 of the Alps, one common source of heat, to the agency of which in 

 remote ages, the mountains originally owed their elevation ; for we 

 can scarcely doubt, that the hot springs in the Alps, like those in 

 Auvergne, in Italy, or Iceland, derive their great temperature from 

 subterranean fire. This inference is farther supported by the well 

 authenticated fact, that the districts in which the hot springs are situ- 

 ated have been subject to great and frequent convulsions. In the 

 year 1755, the ground in the vicinity of the hot springs of Leuk and 

 Naters, in the Upper Valois, was agitated with earthquakes, every 

 day from the 1st of November to the 27th of February. Churches 

 were thrown down, the springs were dried up, and the waters of the 

 Rhone were observed to boil, in several places. The mountain above 

 the warm spring at Naters is said to have opened and discharged a 

 quantity of hot water. 



The hbt springs at the feet of the Pyrenees probably derive their 

 temperature from the same source as those of the Pennine Alps. 

 Hot springs also occur in Dauphiny and Provence, which have prob- 

 ably a similar source of heat. 



What has been here advanced may be sufficient to show the high 

 probability that the elevation of the vertical beds in the Alps has 

 been effected by subterranean heat, — an agent which we have direct 

 proof has, in our own times, elevated considerable portions of the 

 crust of the globe; and it were contrary to the rules of sound philos- 

 ophy to seek for other causes than those which are now existing, 

 when such causes are adequate to the production of the phaenomena 

 we observe. 



Two cases are mentioned by M. Elie de Beaumont, in the " Me- 

 moires de la Societe d'Histoire Naturelle," tom. v., of granite cut- 

 ting through and covering secondary rocks ; such cases, however, 

 demand the strictest scrutiny before the fact can be regarded as well 

 established. In the " Bulletin de la Societe Geologique de France," 

 tom. ii., a section is given of the Jungfrau Mountain, in the canton 

 of Berne, representing two cone-shaped masses of limestone pene- 

 trating the granite near the summit. I spent some weeks almost 

 close to the mountain, and studied its structure with particular at- 

 tention, and I have no hesitation in expressing a decided opinion 

 that the section is fallacious. The part represented as penetra- 

 ted by the limestone is concealed by a covering of eternal snow. 

 The granite, which the author improperly calls gneiss, is small 



