28 On the Revolutions which have 



ering, but to a subterranean force acting from below upwards ; 

 and this appears evident from the whole tenor of geological 

 observations.* 



The portions of the bottom of this sea which are nearest to. 

 the canton of Vaud, and which seem to have been the first 

 raised, and laid dry, are the Vosges, with the very small group 

 of the Alps of the Valais and of Savoy, extending from the 

 base of the Dent de Morcles as far as the Tarentaise, in the 

 direction of the valleys of the Trient and of Chamouny, as they 

 exist at the present day. 



Several geological facts render it probable, that this forma- 

 tion did not form a continuous mass above the waters ; but ra- 

 ther a series of islands, running in a line from north-west to 

 south-east. 



At this distant epoch, before the earth was so much cooled 

 as it now is, these new regions must have had nearly the same 

 climate as that which is enjoyed in the present day by the 

 countries situated between the tropics. Thus the vegetation 

 which was quickly established on them, had the character of 

 that now observed on the islands of the Torrid Zone, as is 

 seen by the vegetable impressions preserved in the clay-slates of 

 Erbignon, Salvan Getroz (valley of the Trient), the Col de 

 Balme, and the Tarentaise ; for these impressions are chiefly 

 of ferns which are for the most part arborescent, equisetacese, 

 lycopodiacea?, and monocotyledonous plants, but which differ 

 from the species, and even from the genera of the present day. 

 The considerable thickness of the deposits of anthracite con- 

 tained in this formation, at Outre Rhone, Servan, Servoz, and 

 in the Tarantaise, indicates that this vegetation was vigorous, 

 and that it lasted a long time ; because these carbonaceous beds 

 are evidently the product of that ancient vegetation whose 

 forms have perished. The destruction of these accumulated 

 vegetables was the result of a violent pressure of the rocks de- 

 posited on them by later revolutions, and perhaps also of a 

 strong heat, to the action of which this formation seems to have 

 been afterwards exposed. 



It appears that this primitive sea, if I may use the expres- 



* See th works of Von Buch and Elie de Beaumont on the subject of 

 Soulevement. 



