534 HISTORY OF GEOLOGY. 



the Alps to those of the north-west of Europe. The dark-colored 

 marbles and schists resembling mica slate 10 were, during the preva- 

 lence of the Wernerian theory, referred, as was natural, to the transi- 

 tion class. The striking physical characters of this mountain region, 

 and its long-standing celebrity as a subject of mineral ogical examina- 

 tion, made a complete subversion of the received opinion respecting 

 its place in the geological series, an event of great importance in the 

 history of the science. Yet this was what occurred when Dr. Buck- 

 land, in 1820, threw his piercing glance upon this district. He imme- 

 diately pointed out that these masses, by their fossils, approach to the 

 Oolitic Series of this country. From this view it followed, that the 

 geological equivalents of that series were to be found among rocks in 

 which the mineralogical characters were altogether different, and that 

 the loose limestones of England represent some of the highly-compact 

 and crystalline marbles of Italy and Greece. This view was confirmed 

 by subsequent investigations ; and the correspondence was traced, not 

 only in the general body of the formations, but in the occurrence of 

 the Red Marl at its bottom, and the Green Sand and Chalk at its 

 top. 



The talents and the knowledge which such tasks require are of no or- 

 dinary kind ; nor, even with a consummate acquaintance with the well- 

 ascertained formations, can the place of problematical strata be decided 

 without immense labor. Thus the examination and delineation of 

 hundreds of shells by the most skilful conchologists, has ben thought 

 necessary in order to determine whether the calcareous beds of Maes- 

 tricht and of Gosau are or are not intermediate, as to their organic 

 contents, between the chalk and the tertiary formations. And scarcely 

 any point of geological classification can be settled without a similar 

 union of the accomplished naturalist with the laborious geological 

 collector. 



It follows from the views already presented, of this part of geology, 

 that no attempt to apply to distant countries the names by which the 

 well-known European strata have been described, can be of any value, 

 if not accompanied by a corresponding attempt to show how far the 

 European series is really applicable. This must be borne in mind in 

 estimating the import of the geological accounts which have been 

 given of various parts of Asia, Africa, and America. For instance, 

 when the carboniferous group and the new red sandstone are stated to 



1(1 De la Beche, Manual. 813. 



