ern than the
limestone of Jura, and the greensand which they have raised,
and more ancient than the tertiary strata and the diluvium.

"The western Alps, and among them Mount Blanc, have, like the
Pyrenees, raised the limestone of Jura, and the greensand, but,
in addition, they have also raised the tertiary formations; the
diluvium is alone horizontal in the vicinity of these
mountains.

"The date of the elevation of Mount Blanc must, therefore,
inevitably be placed between the epoch of the formation of the
tertiary strata and the diluvium.

"Finally, upon the sides of the central Alps, (Mount St.
Gothard,) and of the mountains of Ventorix and Liberon, near
Avignon, no one of the sedimentary formations is horizontal;
all the four have been raised up. When these mountains arose,
the diluvium itself must have already been deposited."

"The sedimentary formations appear, from their nature, and the
regular disposition of their layers, to have been deposited in
times of tranquillity. Each of these formations being
characterized by a particular system of organized beings, both
vegetable and animal, it is indispensable to suppose, that
between the epochs of tranquillity, corresponding to the
precipitation of two of these overlying formations, there must
have been a great physical revolution upon the globe. We now
know that these revolutions have consisted in, or at least been
characterized by, the raising of a system of mountains. The two
first liftings-up pointed out by M. de Beaumont, not being by
any means the greatest of the four he has succeeded in
classing, it will be seen that we cannot infer that the globe,
in growing older, becomes less fit to experience this species
of catastrophe, and that the present period of tranquillity may
not be terminated like those that have preceded it, by the
elevation of some immense mountain chain."

M. de Beaumont next attempted, by a fancied arrangement of zones and
parallels to great circles, to classify the mountains he had not an
opportunity of examining, with those in respect to which he had obtained
the above satisfactory conclusions. We fear, however, that he has
proceeded to theorize too speedily, and before he had obtained a
sufficient number of facts. We are certain, that in respect to the great
Alleghany group o