But erelong these indirect taxes proved unproductive, and recourse was
had to the lasting scourge of _direct taxes_. One of 5 per cent on
legacies and inheritances was first imposed by Augustus, and adhered to
by him, in spite of the indignant murmurs of the Roman nobles and
people. The rate was raised by Caracalla to a tenth of all inheritances;
and, when the privilege of Roman citizenship was extended to the whole
provincials of the empire, they were subjected at once both to the
former burdens which they had paid as provincials, and the new tax
levied on them as Roman citizens.[33] From that time, the direct burdens
became daily more oppressive, and at length proved an almost
insurmountable bar to industry. "The noxious weed," says Gibbon, "sprung
up with the most luxuriant growth, and in the succeeding age darkened
the Roman world with its deadly shade. In the course of this history, we
shall be too often summoned to explain the land-tax, the capitation, and
the heavy contributions in corn, wine, oil, and meat, which were exacted
from the provinces for the use of the court, the army, and the
capital."[34]

These direct taxes soon became fearfully oppressive, and it is proved,
by the clearest evidence, that they were among the leading causes of the
decline of the empire. "The whole landed property of the empire," says
Gibbon, "without excepting the patrimonial estates of the monarch, was
the object of ordinary taxation, and every new purchaser contracted the
obligations of the former proprietor. An accurate survey was made of
what every citizen should contribute to the public service, and this was
made anew every fifteen years. The number of slaves and cattle
constituted an essential part of the report; _an oath was administered
to the proprietors, which obliged them to disclose the true state of
their affairs_; and any attempt to prevaricate or elude the vigilance of
the legislature, was severely watched, and punished as a capital crime,
which included the double guilt of treason and sacrilege. A large
portion of the tribute was paid in money; and, of the current coin of
the empire, _gold alone could be legally accepted_. The remainder of the
taxes, according to the proportion observed in the annual indiction, was
levied in a manner still more direct and still more oppressive.
According to the different value of lands, their real produce, in the
various articles of wine or oil, corn or barley, wood or iron, was
t