Russia and the Ural Mountains. 535 
climate, then is there also a total absence of great boulders. On 
this point I would further beg to remind you, that in our examina- 
tion of the Ural Mountains, even up to 60° north latitude, my com- 
panions and myself could trace no evidence whatever of boulders 
having been transported from these mountains to great distances 
upon their flanks; although the peaks rise to heights of 5000 and 
6000 feet above the sea, and the chain extends from north to south 
through eighteen degrees of latitude. In every portion of the Ural 
Mountains, and on both their Asiatic and European flanks, the 
detritus is of a purely local character; and in it are occasionally 
entombed the bones of the Mammoth, Rhinoceros tichorrhinus, and 
other great extinct quadrupeds, mixed up with gold sand and gravel. 
Transporting ourselves to the south of Russia, we find the upper 
portion of the cliffs of the Sea of Azof composed of local detritus 
and clay equally charged with the same remains. 
The general examination of Russia proves in the most emphatic 
manner, that the central masses of her continent, though exempt 
from all plutonic agency, have undergone grand but tranquil oscilla- 
tions which have scarcely at all disturbed the physical outlines of 
the ancient bottoms of the sea—oscillations which have operated in 
a similar manner over this vast space from the remote Silurian age, 
to the close of the period antecedent to the historic era. This sur- 
vey has also taught us, that the great Russian continent is surrounded 
by rocks of igneous origin, the eruptions of which have corrugated 
and diversified certain portions of the surface at different periods. 
On her eastern or Asiatic side it has been the wish of my 
friends and myself to endeavour to read off in the Ural Mountains 
the effects of such derangements, and to trace the sedimentary de- 
posits of Russia through the mazes of that band of great disturb- 
anee. Having so recently laid before you the outline of our views 
concerning this chain, and being aware that you will soon be in 
possession of much additional knowledge respecting it from the pen 
of the illustrious Humboldt, I will confine myself to a single para- 
graph, by saying that our chief object was to refer these broken and 
altered masses to their normal types. 
We found this highly metamorphic chain, so rich in metalliferous 
masses, to consist essentially of Silurian, Devonian and Carbonife- 
rous rocks, the fossils of which we traced at intervals, notwithstand- 
ing the countless ridges of igneous matter and the highly crystalline 
structure which has been communicated by its eruption to the con- 
tiguous sedimentary strata. A short period only has elapsed, since 
rocks haying quartzose, micaceous and gneissose characters would 
not have been admitted into the same category with strata con- 
taining organic remains; but the theory of metamorphism, founded 
on patient observation and comparison, has prevailed over ancient 
doctrines. The sedimentary rocks of the Ural being paleozoic, 
must, indeed, be viewed as among the most ancient of the meta- 
morphic class. Many other crystalline chains are of much more 
recent age, as long ago, indeed, shown by M. Leopold Von Bueh 
and other observers. Of the truth of this I will first adduce proofs 
