150 Sketch of a Classification 



of this stricture is in reality but small, and principally 

 confined to certain portions of Europe; and even in many of 

 these portions we are continually presented with new views 

 and a detail of newly-discovered phaenomena by able observers, 

 which so modify our previously received opinions as in many 

 instances almost to amount to a change of them. Still, how- 

 ever, a large mass of information has been gradually collected, 

 particularly as respects this quarter of the world, tending to 

 certain general and important conclusions ; among which the 

 principal are, — that rocks may be divided into two great classes, 

 the stratified and the unstratified ; — that of the former some 

 contain organic remains, and others do not ; — and that the non- 

 fossiliferous stratified rocks, as a mass, occupy an inferior 

 place to the fossiliferous* strata, also taken as a mass. The 

 next important conclusion is, that among the stratified fossili- 

 ferous rocks there is a certain order of superposition, marked 

 by peculiar general accumulations of organic remains, though 

 the mineralogical character varies materially. It has even 

 been supposed that in the divisions termed formations, there 

 are found certain species of shells, &c. characteristic of each. 

 Of this supposition, extended observations can alone prove the 

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

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

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

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

 districts 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 infer 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 uniform distribution of animal and vegetable life, 

 it seems necessary, judging from the phaenomena we now 

 witness, that there should also have been an uniform tempera- 

 ture over the surface of our planet. To obtain this, solar 



* The term fossiliferous is here confined to orgauic remains. 



