se who remained in the rural districts; for, as the
taxes of each municipality remained the same, every one that withdrew
into the towns left an additional burden on the shoulders of his
brethren who remained behind. So powerful was the operation of these
two causes--the fixity in the state burdens payable by each
municipality, and the constantly declining prices, owing to the vast
import from agricultural regions more favoured by nature--that it
fully equaled the effect of the ravages of the barbarians in the
frontier provinces exposed to their incursions; and the depopulation
of the rural districts was as complete in Italy and Gaul, before a
barbarian had passed the Alps or set his foot across the Rhine, as in
the plains between the Alps or the Adriatic and the Danube, which had
for long been ravaged by their arms.

Domestic slavery conspired with these evils to prevent the healing
power of nature from closing these yawning wounds. Gibbon estimates
the number of slaves throughout the empire, in its latter days, at a
number equal to that of the freemen; in other words, one half of the
whole inhabitants were in a state of servitude;[17] and as there were
120,000,000 souls under the Roman sway, sixty millions were in that
degraded condition. There is reason to believe that the number of the
slaves was still greater than this estimate, and at least double that
of the freemen; for it is known by an authentic enumeration, that, in
the time of the Emperor Claudius, the number of citizens in the empire
was only 6,945,000 men, who, with their families, might amount to
twenty millions of souls; and the total number of freemen was about
double that of the citizens.[18] In one family alone, in the time of
Pliny, there were 4116 slaves.[19] But take the number of slaves,
according to Gibbon's computation, at only half the entire population,
what a prodigious abstraction must this multitude of slaves have made
from the physical and moral strength of the empire! Half the people
requiring food, needing restraint, incapable of trust, and yet adding
nothing to the muster-roll of the legions, or the persons by whom the
fixed and immovable annual taxes were to be made good! In what state
would the British empire now be, if we were subjected to the action of
similar causes of ruin? A vast and unwieldy dominion, exposed on every
side to the incursions of barbarous and hostile nations, daily
increasing in numbers, and augmenting in military