Within about sixty years from the final consolidation of the Empire under Augustus, this continuous efflux of the precious metals began to cause the currency to contract, and prices to fall; and the first effect of shrinking values appears to have been a financial crisis in 33 A.D. Probably the diminution in the worth of commodities relatively to money, had already made it difficult for debtors to meet their liabilities, for Tacitus has prefaced his story by pointing out that usury had always been a scourge of Rome, and that just previous to the panic an agitation against the money-lenders had begun with a view to enforcing the law regarding interest. As most of the senators were deep in usury they applied for protection to Tiberius, who granted what amounted to a stay of proceedings, and then, as soon as the capitalists felt themselves safe, they proceeded to take their revenge. Loans were called, accommodation refused, and mortgagors were ruthlessly sold out. “There was great scarcity of money ... and, on account of sales on execution, coin accumulated in the imperial, or the public treasury. Upon this the Senate ordered that every one should invest two-thirds of his capital on loan, in Italian real estate; but the creditors called in the whole, nor did public opinion allow debtors to compromise.” Meanwhile there was great excitement but no relief, “as the usurers hoarded for the purpose of buying low. The quantity of sales broke the market, and the more liabilities were extended, the harder liquidation became. Many were ruined, and the loss of property endangered social station and reputation.”[37] The panic finally subsided, but contraction went on and next showed itself, twenty-five years later, in adulterated coinage. From the time of the Punic Wars, about two centuries and a half before Christ, the silver denarius, worth nearly seventeen cents, had been the standard of the Roman currency, and it kept its weight and purity unimpaired until Nero, when it diminished from 1⁄84 to 1⁄96 of a pound of silver, the pure metal being mixed with 1⁄10 of copper.[38] Under Trajan, toward 100 A.D., the alloy reached twenty per cent; under Septimius Severus a hundred years later it had mounted to fifty or sixty per cent, and by the time of Elagabalus, 220 A.D., the coin had degenerated into a token of base metal, and was repudiated by the government. Something similar happened to the gold. The aureus, though it kept its fineness, lost in weight down to Constantine. In the reign of Augustus it equalled one-fortieth of a Roman pound of gold, in that of Nero one forty-fifth, in that of Caracalla but one-fiftieth, in that of Diocletian one-sixtieth, and in that of Constantine one seventy-second, when the coin ceased passing by tale and was taken only by weight.[39]