ANNIVERSARY ADDRESS OF THE PRESIDENT. cli 



cipally characterized by the formation of natural groups in which 

 are merged several of the sections adopted by the American geo- 

 logists, and the establishment of a " Middle Silurian" stage, as also 

 a similar Middle Devonian. This tripartite classification would of 

 course assimilate these two great formations to the Permian and 

 Triasic, and thus introduce a certain amount of harmony in the system 

 of classification, even though it might not be an exactly true repre- 

 sentation of nature. After a most careful lithological and palaeon- 

 tological description of the strata, he deduces some interesting con- 

 clusions, as, for example, that all the strata from the Potsdam sand- 

 stone to the summit of the carboniferous were quietly deposited, 

 being subjected only to occasional vertical oscillations and conse- 

 quent superficial changes ; and that the elevation, fracture, and 

 metamorphism of the strata were subsequent to the deposition of 

 the whole, in one prolonged operation, and in a N.E. and S.W. di- 

 rection along the Appalachians, so well described by the Professors 

 Rogers, whose views Dr. Bigsby fully states, though he does not 

 entirely agree with them. 



It is trusted that the preceding review of the works of the last 

 session will prove that our members and contributors have exhi- 

 bited zeal, energy, and ability in following up the study of every 

 branch of our science ; and that our foreign fellow-labourers have 

 been equally zealous and successful : but, to the proof my previous 

 citations have afforded, I may add a reference to the last publi- 

 cations of Yon Hauer, Oppel, Jokely, Ludwig, Neumann, and many 

 others, as being sufficient to show that in every quarter the mate- 

 rials are collecting which will hereafter enable the philosophic geo- 

 logist to describe the history of the earth in all its physical and 

 organic changes, though I cannot presume to trespass further on 

 your attention by dwelling upon the works of these able authors ; 

 I must, however, notice very briefly some recent observations of 

 M. Alph. Favre, Professor of Geology at the Academy of Geneva, 

 on that portion of the stratification of Savoy which has so long 

 been a puzzle to the geologist. M. Sismonda and M. Elie de Beau- 

 mont appear to have considered the several beds of coal as all 

 belonging to one epoch ; and the first of these eminent geologists 

 having found in the bed of coal of Taninge the impressions of true 

 coal-plants above, as he supposed, the Jurassic strata, he adopted the 

 bold assumption, that " in the Alps the coal-ferns continued to live 

 on, whilst deposits were taking place in the sea, up to the nummu- 

 litic epoch," to which therefore he assigned the coal of Taninge ; and 

 M. EHe de Beaumont considered the coal of the Diablerets, Darbon, 

 Taninge, &c. to be so far of the same age as to be all comprised 

 within the nummulitic period. M. Favre, on the contrary, who is 

 well known as one of the most active and successful explorers of 

 Alpine geology, states that in the neighbourhood of Taninge, which 

 he had often visited, he found at a high elevation a fine deposit 

 of hypersthene and serpentine rocks not before noticed ; that to the 

 S.W. of Taninge, on the summit called La Yuarde, he collected 

 very characteristic Liassic fossils ; and that he traversed in every 



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