of the Etiropean RocJcs. 441 



this supposition, extended observation can alone pi'ove the 

 truth ; and in order properly to investigate the subject, geo- 

 logists must agree to what mass of rocks they should limit the 

 term Formation : if, as some now do, they apply it to every ac- 

 cumulation of ten or twenty beds, which may happen, in the 

 district they have examined, to contain a few shells not found 

 in the strata above and beneath, the investigation is not likely 

 to lead to any extended conclusions. 



To suppose that all the formations into which it has been 

 thought advisable to divide European rocks can be detected 

 by the same organic remains in various distant points of the 

 globe, is to assume that the vegetables and animals distributed 

 over the surface of the world were always the same at the same 

 time, and that they were all destroyed at the same moment to 

 be replaced by a new creation, differing specifically if not ge- 

 nerically from that which immediately preceded. This theory 

 would also inier that the whole surface of the world possessed 

 an uniform temperature at the same given epoch. 



It has been considered, but yet remains to be proved, that the 

 lowest fossiliferous rocks correspond generally in their fossil 

 contents, in places far distant from each other. Let us for the 

 moment suppose this assertion to be correct. To obtain this uni- 

 form distribution of animal and vegetable life, it seems necessary, 

 judging from the pha^nomena we now witness, that there should 

 also have been an uniform temperature over the surface of our 

 planet. To obtain this, solar influence, as it now exists, would 

 be inadequate; we must therefore have recourse to internal 

 heat to produce the effect required. In the present varied tem- 

 perature of the earth's surface, if we imagine a rock to be 

 formed which should envelop every animal and plant now 

 existing, the fossil contents of one district would differ from 

 the fossil contents of another; if we except man, whose bones 

 would more or less become the characteristic fossils of those 

 portions of the rock which might overlie the present dry land. 

 Tlie rock supposed to be now formed would }nesent a strik- 

 ing contrast with the old fossiliferous, and we should have two 

 very distinct accumulations of organic remains. The ques- 

 tion arising on such phajnomena would be, Has so great a 

 change of organic character been effected gradually or sud- 

 denly ? To supjiose it sudden will not agree with the phacno- 

 niena presented to us, even by the now known European rocks ; 

 and if it be considered gradual, we cannot expect that rocks 

 should every where contain the same organic remains, even 

 in those that have been commonly called secondary: conse- 

 quently the organic remains considered characteristic of any 

 N.S. Vol. 6. No. 36. Dec. 1829. 3 L ' particular 



