520 Progress of Geological Science. [Not. 



" If indeed we were to admit a period of intense volcanic violence, and a sudden 

 elevation of the Scandinavian chain, we might then have a cause commensurate 

 to the effects observed, and in the rush of the retiring waters, we might ex- 

 plain the transport of those great boulders which lie scattered over the northern 

 plains of Europe. But in the speculations I am combating, all great epochs of 

 elevation are S3 r stematically, and I think unfortunately, excluded. Volcanic ac- 

 tion is essentially paroxysmal ; yet Mr. Lyell will admit no greater paroxysms 

 than we ourselves have witnessed — no periods of feverish spasmodic energy, dur- 

 ing which the very frame -work of nature has been convulsed and torn asunder. 

 The utmost movements that he allows are a slight quivering of her muscular 

 integuments." 



These objections to Mr. Lyell's theory are perhaps carried too far : he does 

 not insist upon the absence of all violent paroxysms, so much as he labours to give 

 due weight to the power of causes now in operation. The existence of a vast 

 depression on the earth's surface, extending beyond the Caspian and the Aral, 

 might be adduced as an illustration of great operations still working hefore our 

 eyes ; should any fissure be laid open by subterranean force, so as to connect this 

 basin with the nearest ocean, we should suddenly witness a deluge, attended with 

 proportionate convulsions, over a space ascertained by M. de Humboldt and 

 Col. Monteith to extend over at least 18000 square leagues, reaching to Saratof 

 Orenburg, and the low regions of the Oxus and the Jaxartes : the lowest level 

 of this vast basin is 300 feet below the Mediterranean*. 



Mr. R. J. Murchison, the present President of the Geological Society-f-, was a fel- 

 low labourer with Mr. Lyell, when his mind was first led to the line of investigation 

 which he has since developed. It was in their tour along the southern shores 

 of the Mediterranean, and subsequently in the north of Italy, that Mr. Lyell's 

 attention was particularly directed to the distribution of the tertiary strata into 

 new groups, according to the proportional number of shells identical with living 

 species, found fossil in each formation : after examining the Sub-Apennine shells, 

 he pursued his inquires in Naples and Sicily, where disturbing causes have been 

 in continual action from remote antiquity, hoping to ascertain whether successive 

 and distinct creations of organic remains might not have been elevated from be- 

 neath the sea, by a series of subterranean convulsions, continued from the period 

 of the mixed Sub-Apennine deposits, uninterruptedly, to the historic aera. He here 

 began to unfold the true papyri of geological history : in many mountains of 

 considerable magnitude, the extinct species had nearly disappeared, and in other 

 vast accumulations of fossil marine shells, nearly all were specifically identical 

 with those now inhabiting the adjoining sea. Thus, by a series of deductions, he re- 

 moved as arbitrary and untrue those lines of demarcation between what had termed 

 the ancient and the existing orders of nature; and he had the satisfaction to find, that 

 the same train had been developed by M. Desnoyers and M. Deshayes, from a 

 close examination of the Paris basin. 



* Professor Mure bison's Address, 1832, Phil. Mag. lxv. p. 384.— Gl. in Sc. III. 

 330. The Academy of St. Petersburg, at the instigation of M. de Humboldt, is now 

 engaged in directing surveys and barometrical " soundings," as they are emphatically 

 styled, by which the precise extent, depths, and true shore of this dry Caspian will be 

 accurately defined. 



f Annual Address, 1832, Phil. Mag. lxv. 375. 



