270 AN ENQUIRY INTO THE NATURE OF [ Ch XIII. 



Some geologists, indeed, are of opinion, that both extinct 

 and active volcanos afford examples of the permanent eleva- 

 tion of the strata, since these sometimes dip on all sides from 

 the centres of these igneous mountains. Others, however, 

 refuse to acknowledge the existence of such craters of eleva- 

 tion ; and this subject has occasioned several animated 

 discussions at the meetings of the Geological Society 

 of France ; Montlosier, De Beaumont, and Dufrenoy main- 

 taining, and Cordier and Prevost opposing, this opinion. 

 Cordier, in particular, has expressed his dissent in very 

 strong terms : "La denomination de cratere de soulevement 

 est aussi fausse et aussi vicieuse que 1'hypothese, qu'on a eu 

 1'intention de qualifier par son moyen. En effet, cette hypo- 

 these est gratuite ; elle pose en fait 1'existence et le renou- 

 vellement multiplie d'un phenomene qui est sans exemple, et 

 qui d'ailleurs, par les forces prodigieuses et purement locales 

 qu'il aurait exigees, ne serait en aucun rapport avec I'intensite" 

 et la nature des effets volcaniques authentiquement constates.'* 

 The same eminent philosopher, after having enumerated the 

 various kinds of craters, states that their formation is accom- 

 panied by tremendous detonations, and thus concludes : "La 

 percee du sol n'en est pas moins un phenomene purement local, 

 qui n'affecte, pour ainsi dire, qu'un point dans la masse du 

 terrain traverse, qui opere sans soulevement aucun de cette 

 masse, qui s'effectue par une serie de fentes tres peu etendues, 

 et dont les effets paraissent excessivement minimes quand 

 le bruit a cesse." * 



It is at present, therefore, undecided, whether strata have 

 or have not been elevated into an inclined position by volcanic 

 action ; but it appears very probable that, when the highly 

 expansive vapours connected with the volcanic force, cannot 

 force their way through the incumbent strata, so as to cause 

 an eruption, this power is not always exerted in vain ; but, at 

 each renewed effort, it raises up bodily not only large tracts 



* Bulletin de la Soci&e' Ge"ol. de France, tome ii. p. 399. 



