103 



Certain fossils whi<;h he had brought to France, anJ "vvhieh we 



inspected before our journeys to Russia (1840), first led us to be-> 

 lieve, that these coal beds are subordinate to the carboniferous 

 limestone. Of this, indeed, there could be no doubt, for the species 

 were, to a great extent, the very same as those with which we 

 were familiar in rocks of that age in Avestern Europe. On in- 

 terrogating M. Le Play, however, we could not ascertain that Im 

 had arrived at any defined idea of a succession of strata, derived 

 either from the stratigraphical order of mineral masses, or from their 

 imbedded organic remains. In fact, he then distinctly acquainted 

 us with what has now appeared in his work, that, owing to the dis- 

 turbed and convoluted condition of the strata, the wazit of persist-- 

 ency of mineral characters, and the apparent existence of simjlai* 

 species of shells throughout the series, it was impracticable to as-? 

 sign a base line to the deposits, or to trace their uppermost limits, 

 still less a passage into any superior formations. 



Now, as we have ventured to effect these objects, with what suc- 

 cess we must leave others to decide, I will here briefly stat§ why 

 I conceive M. Le Play did not arrive at similar results ; although 

 he liad in his own hands some means of proof, which, through 

 the short time at our disposal, we never obtained. 



No geologist, however practised, can, I venture to say, explain 

 the structure of any complicated part of a distant country, ujjless 

 he has made himself master of the clear succession of its normal 

 formations. Long as I have been occupied in the study of the Palaeo- 

 zoic rocks, I am confident that, had my fi'iends and myself been 

 thrown suddenly into the chain of the Donetz, and had been desired 

 at once to unravel its complexity, we should have reached no other 

 geological result than that to which M. Le Play has attained, viz. of 

 stating tliat the coal-seams are, as a whole, subordinate to the car- 

 boniferous or mountain limestone. We had, however, by two years 

 of extensive comparative researches, obtained an intimate acquaint- 

 ance, not only with the older Palaeozoic rocks of Russia generally, 

 but, in reference to the carboniferous system, had convinced our* 

 selves, that, throughout the enormous area over which we had traced 

 it, the upper or coal group of western Europe was absent ; and that 

 the calcareous or lower group, occupying the whole carboniferous 

 horizon, was divisible into three stages, by help of certain fossib 

 characteristic of each. Again, w'e luid ascertained, by numerous 

 sections on both flanks of the Ural Mountains, that, in becoming 

 part of a mountain mass, this system, so uniform and so peculiar 

 over a space as large as an ordinary European kingdom, put on 

 many of the features v/hich are so well known to those who have 

 studied the carboniferous limestone only in the western parts of 

 ^^iijope. 



We further learnt, that, in the absence of any deposits to repre- 

 sent our great coal-fields, the carboniferous system was succeeded, 

 in ascending order, by a vast series of red and cupriferous deposits 

 to which we have assigned the name of Permian. It will not, 

 therefore, be arrogant on our part to say, that we entered upon 



