208 Dr Daubeny on tlie Diluvial Theory^ 



established ; and that in many instances one of the first effects 

 of the igneous agency seems to have been the throwing up of a 

 cone sometimes many thousand feet in height, and of propor- 

 tionate diameter. 



This latter notion, however, has been controverted by Mr 

 Scrope, and after him by Mr LyelJ, both of whom appear to 

 regard every sort of volcanic mountain as occasioned merely by 

 the accumulation of the products of many successive eruptions. 

 Now, I must allow, that the latter geologist has succeeded in 

 removing one of the strongest objections I had formerly enter- 

 tained against the theory originally proposed by Mons. Necker, 

 and adopted by himself and Mr Scrope, which arose from the 

 difficulty of imagining the brim of a crater to continue through- 

 out so uniformly level, as to allow the lava to flow at once over 

 all its sides. This supposition he seems to have shewn not to 

 be necessary, since the beds which constitute a volcanic cone, 

 when carefully examined, do not appear to be continuous belts 

 extending round the mountain*, but a sort of compensation ex- 

 isting between the matters ejected from the several sides of the 

 crater, which produces on the great scale a fallacious appearance 

 of regularity. 



But whilst I admit the possibility of explaining in such a 

 manner the origin of this description of cone, I am at a loss to 

 extend the same hypothesis to mountains of trachyte, which, 

 like the Puy de Dome, or some of the volcanos of the Andes, 

 occur detached in the midst of a chain of differently constituted 

 rocks, and appear to maintain in a great degree the figure which 

 they must have possessed when first generated by volcanic 

 action. 



To me at least it seems, that every attempt that has been 

 hitherto made to account for the formation of such hills without 

 having recourse to Von Buch's hypothesis, is encumbered with 

 much more formidable objections ; and I could wish those who 

 are sceptical on the subject, and are disposed to cavil at the un- 

 necessary introduction (as they conceive) of a new principle, to 

 suspend their decision until they have examined the five domitic 

 hills in Auvergne, and considered in what other manner they 



• I had overlooked a passage in p. 168 of Mons. Necker's Memoir, in 

 which the same circumstance is stated. 



