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346 Geology. — On the Order of Succession of Rocks, 



explanation we have given of the meaning of the term. The re- 

 maining part of the series, from the coal to the chalk inclusive, 

 is universally called secondary. 



The tertiary includes that portion of the series from the chalk 

 to the present surface of the earth. It is replete with interest, 

 whether we consider it as the terminating part of a long series 

 of rocks, connecting the present with the ancient order of nature, 

 or as being rich, in an exceeding manner, in marine, fresh wa- 

 ter, and organic remains. 



The other subdivision of the geological series into five orders, 

 superior, supermedial, medial, submedial and inferior, is from the 

 Rev. Mr. Conybeare. It is disconnected with every kind of the- 

 ory, and pretends to no merit beyond the very convenient man- 

 ner in which it arranges the geological series into five subdivisions. 

 There is not a more gifted geologist in Europe, than Mr. Cony- 

 beare ; nor one more capable, in the present state of the science, 

 of offering to the public a more philosophical arrangement, 

 founded upon natural distinctions. 



We have prefixed numbers to the beds, for more convenient re- 

 ference, beginning with granite, the lowest of the primary rocks, 

 and terminating with No. 41, the superficial alluvium, being the 

 last bed in the series, and that which is constantly forming by 

 the agency of floods, streams, and tides. The other column of 

 numbers represents the average thickness of the respective 

 beds in Europe, as it has been computed by the most reputed 

 geologists. 



It is proposed, in the course of these essays, to review each of 

 these beds in detail ; explaining their position, mineral structure, 

 and the nature of the organic remains imbedded in them. An 

 opportunity will then be presented of describing the beds in 

 North America, and of comparing the geological phenomena be- 

 longing to them, with those of other countries. It is by such 

 means alone, that an effectual progress in general geology can 

 be made ; for, to use the language of the Rev. Mr. Conybeare, 

 *' zoe may he sure that any analogies which are common to localitiesy 

 geographically so distant^ and placed under physical conditions so 

 distinct, are, in truth, analogies belonging generally to the whole globe; 

 and thus we shall obtain a data adequate for the foundation of a ^ 

 general geological theory.'''' The attention which has been hitherto 

 paid to North American geology, has been, comparatively, so 



