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 transported by the labour, or at the expense of the provincials, to the imperial magazines, from whence they were occasionally distributed for the use of the court, the army, and the two capitals, Rome and Constantinople. The commissioners of the revenue were so frequently obliged to make _considerable purchases_, that they were strictly prohibited from allowing any compensation, or from receiving in money the value of those articles which were exacted in kind."[35]