Oural mountains with the general strata of
the Russian plains, then, as to the contained minerals, we may find a
certain diversity in those two places; at the same time, no greater
perhaps than may be found betwixt two different bodies in those same
plains, for example, chalk and flint. But when we consider those bodies
of the earth, or solid strata of the globe, in relation to their proper
structure and formation, we surely can find in this description nothing
on which may be founded any solid opinion with regard to a different
original, however important conclusions may perhaps be formed with
regard to the operations of the globe, from the peculiar appearances
found in alpine.

From this detail of what is found in the Oural mountains, and in the
gradation of country from those mountains to the plains of Russia, we
have several facts that are worthy of observation. First extensive
mountains of jasper. I have a specimen of this stone; it is striped red
and green like some of our marly strata. It has evidently been formed of
such argillaceous and siliceous materials, not only indurated, so as to
lose its character, as an argillaceous stone, but to have been brought
into that degree of fusion which produces perfect solidity. Of the same
kind are those hornstein rocks of the nature of flint, sometimes tending
to the nature of a fine sandstone. Here is the same induration of
sandstone by means of fusion, that in the argillaceous strata has
produced jasper. But oblique veins of jasper are represented as
traversing these last strata; now this is a fact which is not
conceivable in any other way, than by the injection or transfusion of
the fluid jasper among those masses of indurated strata.

All this belongs to the east side of the mountains. On the west, again,
we find the same species of strata; only these are not changed to such a
degree as to lose their original character or construction, and thus to
be termed differently in mineralogy.

Our author then proceeds. (p. 53.)

"Nous pourrons parler plus decisivement sur les _montagnes secondaires
et tertiaires_ de l'Empire, et c'est de celles-la, de la nature, de
l'arrangement et du contenu de leurs couches, des grandes inegalites et
de la forme du continent d'Europe et d'Asie, que l'on peut tirer avec
plus de confiance quelques lumieres sur les changemens arrives aux
terres habitables. Ces deux ordres de montagnes presentent la chronique
de notre globe la plus ancienne,