changed the Surface of Switzerland. 36 



and sinkings of the raised bands of rocks, gave rise to those 

 kinds of crevices and rents in the form of furrows, which we 

 denominate valleys. This revolution was the last, up to the 

 present time, which changed the surface of Switzerland. It 

 formed the existing valleys, and, in a certain degree, gave to the 

 mountains the aspect which they now exhibit. It changed the 

 climate, caused the disappearance of the ancient vegetation, and 

 the destruction of the animals which, until that period, had inha- 

 bited Switzerland. Finally, it produced the conditions necessary 

 for the existence of the organized beings which now adorn and 

 animate this beautiful country. 



Great masses of rocks fell back into the vast crevices, which, 

 having remained open, form our principal valleys. When these 

 detached masses were not completely covered by the alluvium 

 which gradually filled to a certain height the bottom or soil of 

 the fissures, they became those isolated rocks, presenting great- 

 er or less escarpments, which we are astonished to see rising up 

 in the centre of some valleys. That of the Rhone presents se- 

 veral striking examples, as at Saint Tryphon, near Ollon, at 

 Mont d'Horge, and at Tourbillon, near Sion. 



Moreover, by this same catastrophe, vast portions of rock 

 were sunk to so great a depth as not to allow of the subsequent 

 alluvium filling up the hollows which had resulted from it ; these 

 last, being afterwards filled with water, produced those lakes 

 which give a peculiar charm to Switzerland, and of which the 

 most beautiful, if not the most extensive, embellishes our canton. 



These partial subsidings, which produced our lakes, and a 

 number of accidens and changes of level, either in the plains 

 or in the mountains, were by no means considerable ; and, in 

 particular, they were much less important in their effects than 

 the general subsidence, which the whole raised mass seems to 

 have undergone. 



For every thing leads to the conclusion, that, at this epoch, 

 not only the Alps, but also the Jura, and the formations which 

 separate those two systems of mountains, were affected by this 

 astonishing revolution, and all raised much higher than they 

 now are. Such a commotion must have caused immense dis- 

 placements, dislocations, and the formation of hollows and ca- 

 vities. The raised mass must then have undergone a subsi- 



VOL. XXII. NO. XLIII. JANUARY 1837. C 



