1859.] SCEOPE CONES AND CRATEES. 513 



of the same volume, M. de Buch asserts that '^ It sprung up at its 

 origin, in the time of Pliny, ready-formed, as we see it " {Le 

 volcan, tel que nous le voyons encore, est sorti, a cet epoque, tout forme, 

 du sein de la terre). " It was not formed," he goes on to say, " by 

 successive out-flowings of currents of lava; on the contrary, its 

 height has, since that epoch, a.d. 79, been constantly diminishing*." 

 Again, of Etna, M. de Buch says, " We cannot refuse to see in it an 

 individual, so to speak, arrived at perfection at the moment of its 



birth It could not have been the result of slow and irregular 



growth, by successive eruptions. Its form is too regular and sym- 

 metincal for such an origin f." 



M. Ehe de Beaumont, who, with M. Dufrenoy, subsequently to 

 M. de Buch, took up and maintained the upheaval- theory, similarly 

 says of the same mountain, Etna : " One day the internal agency 

 which had so frequently disturbed the ' terrain ' (which he had de- 

 scribed as, up to that time, a nearly horizontal plain, composed of 

 volcanic strata), having exerted an extraordinary degree of energy, 

 broke through and upheaved it. From that mx)ment Etna became a 

 mountain.'' He goes on to reject the idea of its upheaval having 

 been gradual, and says, " It was effected suddenly and at one 



stroheX'^^ 



So, again, M. Dufrenoy says of Somma, " The lavas of which it 

 is composed were formed in horizontal sheets, under the sea" — ^' se 

 sont epanchees en nappes horizontales ;" and " it was after this that 

 Somma was upheaved at once §." 



I quote these passages from the works of the chief advocates of the 

 upheaval-theory in order that there may be no misunderstanding as 

 to what it really is, and lest it should again be said (as I have heard 

 it said in this room) that it is only a question of degree, — that both 

 parties to the controversy may be right to some extent, — that truth 

 may lie between them, and so forth. These convenient modes of 

 compromising unpleasant differences of opinion will not apply here. 

 It is a question that admits of no compromise. It is not as to whether 

 some small proportion of the salient rehef of a volcanic cone or 

 mountain, or of the angle of elevation of its outer slopes, or the par- 

 tial disturbance of some of its component beds, may be due to occa- 

 sional earthquake-shocks or other subterranean elevatory impulses, 

 accompanied by the injection of lava into the internal fissures thus 

 formed (afterwards hardened into solid dykes), during the successive 

 eruptions of the volcaiw. That much will be disputed by no one of the 

 Eruptionists (as I may call them), certainly not by myself, who have 

 always described this inward distension of a volcanic mountain in 

 habitual or occasional eruption as part of the gradual process by which 

 it was formed || . But such slow accretions to its solid internal bulk 

 are the very reverse of the process imagined by the Upheavalists. 



* Canaries, p. 342. t Ibid. p. 326. 



J Recherches sur le mont Etna, pp. 188-193. 

 § Terrains de Naples, p. 360. 



II See ' Considerations on Volcanos,' 1825, p. 156, and Trans. Greol. Soc. Lend. 

 2 ser. vol. ii. p. 341, 1827. 



