rivers--the Tigris and Euphrates--with their tributaries, the more
northern part of the Mesopotamian lowland would in no respect differ
from the Syro-Arabian desert on which it adjoins, and which in latitude,
elevation, and general geological character it exactly resembles.
Towards the south, the importance of the rivers is still greater; for of
Lower Mesopotamia it may be said, with more truth than of Egypt, that it
is "an acquired land," the actual "gift" of the two streams which wash
it on either side; being, as it is, entirely a recent formation--a
deposit which the streams have made in the shallow waters of a gulf into
which they have flowed for many ages.

The division, which has here forced itself upon our notice, between the
Upper and the Lower Mesopotamian country, is one very necessary to engage
our attention in connection with the ancient Chaldaea. There is no
reason to think that the terns Chaldaea had at anytime the extensive
signification of Mesopotamia, much less that it applied to the entire
flat country between the desert and the mountains. Chaldaea was not the
whole, but a part of, the great Mesopotamian plain; which was ample
enough to contain within it three or four considerable monarchies.
According to the combined testimony of geographers and historians,
Chaldaea lay towards the south, for it bordered upon the Persian Gulf;
and towards the west, for it adjoined Arabia. If we are called upon
to fix more accurately its boundaries, which, like those of most
countries without strong natural frontiers, suffered many fluctuations,
we are perhaps entitled to say that the Persian Gulf on the south, the
Tigris on the east, the Arabian desert on the west, and the limit between
Upper and Lower Mesopotamia on the north, formed the natural bounds,
which were never greatly exceeded and never much infringed upon. These
boundaries are for the most part tolerably clear, though the northern
only is invariable. Natural causes, hereafter to be mentioned more