As gold had become the sole legal tender, this change of ratio represents a diminution, during the existence of the Western Empire, of at least fifty per cent in the value of property in relation to debt, leaving altogether out of view the appreciation of silver itself, which was so considerable that the government was unable to maintain the denarius.[40] Resistance to the force of centralized wealth was vain. Aurelian’s attempt to reform the mints is said to have caused a rebellion, which cost him the lives of seven thousand of his soldiers; and though his policy was continued by Probus, and Diocletian coined both metals again at a ratio, expansion was so antagonistic to the interests of the monied class that, by 360, silver was definitely discarded, and gold was made by law the only legal tender for the payment of debts.[41] Furthermore, the usurers protected themselves against any possible tampering with the mints by providing that the solidus should pass by weight and not by tale; that is to say, they reserved to themselves the right to reject any golden son which contained less than one seventy-second of a pound of standard metal, the weight fixed by Constantine.[42] Thus, at a time when the exhaustion of the mines caused a failure in the annual supply of bullion, the old composite currency was split in two, and the half retained made to pass by weight alone, so as to throw the loss by clipping and abrasion upon the debtor. So strong a contraction engendered a steady fall of prices, a fall which tended rather to increase than diminish as time went on. But in prolonged periods of decline in the market value of agricultural products, farmers can with difficulty meet a money rent, because the sale of their crops leaves a greater deficit each year, and finally a time comes when insolvency can no longer be postponed. In his opening chapter Gibbon described the Empire under the Antonines as enjoying “a happy period of more than fourscore years” of peace and prosperity; and yet nothing is more certain than that this halcyon age was in reality an interval of agricultural ruin. On this point Pliny was explicit, and Pliny was a large land-owner.