in a
vertical direction.

"May not the inclined deposits that we see upon the slopes of
mountains, have been deposited in inclined or vertical
positions? Or is it not more natural to suppose, that they
originally formed horizontal beds, like the contemporaneous
beds of the same nature with which the plains are covered, and
that they have been lifted up and assumed new directions at the
moment of the elevation of the mountains on whose sides they
rest?

"As a general principle, it does not appear impossible that the
crests of mountains may have been incrusted _in place_, and in
their actual position, by sedimentary deposits, since we daily
see the vertical sides of vessels, in which waters charged with
sulphate of lime evaporate, covered with a saline crust, whose
thickness is continually augmented; but the question before us
does not present this general aspect, for it is merely required
to determine whether the _known_ sedimentary formations can
have been thus deposited. To this question we must reply in the
negative, as can be shown by two species of considerations,
wholly different from each other.

"Incontestable geological observations have shown, that the
calcareous layers which constitute the summits of Buet in
Savoy, and Mount Perden in the Pyrenees, elevated 11,000 or
12,000 feet above the level of the sea, have been formed at the
same time with the chalk of the cliffs that border the British
channel. If the mass of water whence these strata were
precipitated had risen 11,000 or 12,000 feet, the whole of
France would have been covered, and analogous deposits must
have existed upon all heights not exceeding 9,000 or 10,000
feet; now, it is found, on the contrary, that in the north of
France, where these deposits appear to have undergone little
change, the chalk never reaches a height of more than 600 feet
above the level of the present sea. They present precisely the
disposition of a deposit formed in a basin filled with a liquid
whose level has never reached any points that are at the
present day elevated more than 600 feet.

"I pass to the second proof, borrowed from Saussure, and which
appears even more convincing.

"Sedimentary formations often contain pebbles rounded by
attrition, and of a figure more o