oblique channel into the basin of the ocean. These bold hypotheses on
the communication between two neighbouring basins have presented
themselves in every zone to the imagination of the ignorant, as well
as to that of the learned; for the latter, without confessing it,
sometimes repeat popular opinions in scientific language. We hear of
subterranean gulfs and outlets in the New World, as on the shores of
the Caspian sea, though the lake of Tacarigua is two hundred and
twenty-two toises higher, and the Caspian sea fifty-four toises lower,
than the sea; and though it is well known, that fluids find the same
level, when they communicate by a lateral channel.

The changes which the destruction of forests, the clearing of plains,
and the cultivation of indigo, have produced within half a century in
the quantity of water flowing in on the one hand, and on the other the
evaporation of the soil, and the dryness of the atmosphere, present
causes sufficiently powerful to explain the progressive diminution of
the lake of Valencia. I cannot concur in the opinion of M. Depons*
(who visited these countries since I was there) "that to set the mind
at rest, and for the honour of science," a subterranean issue must be
admitted. (* In his Voyage a la Terre Ferme M. Depons says, "The small
extent of the surface of the lake renders impossible the supposition
that evaporation alone, however considerable within the tropics, could
remove as much water as the rivers furnish." In the sequel, the author
himself seems to abandon what he terms "this occult case, the
hypothesis of an aperture.") By felling the trees which cover the tops
and the sides of mountains, men in every climate prepare at once two
calamities for future generations; want of fuel and scarcity of water.
Trees, by the nature of their perspiration, and the radiation from
their leaves in a sky without clouds, surround themselves with an
atmosphere constantly cold and misty. They affect the copiousness of