CHAPTER XII. The Greek System.

merely between one district and another, but even between one period and another in the self-same city or state. There is incontrovertible evidence to prove that the same trouble was caused by the fluctuation in the relative value of gold and silver as arises in modern times. Xenophon⁴⁸ in his treatise De Vectigalibus (speaking of the benefit likely to accrue to the state if the silver mines of Laurium were better worked) makes the most interesting remark that “if any one were to allege that gold too is not less useful than silver, that I do not deny, yet this I know that gold, whenever it turns up in quantity, becomes on the one hand cheaper itself, and on the other makes silver dearer.” This passage alone is sufficient to show how sensitive was the old Greek money market in the beginning of the 4th century B.C., and this statement is amply substantiated on Italian soil by a passage quoted by Strabo⁴⁹ from Polybius, from which we learn that after the discovery of a rich gold mine in the land of the Taurisci of Noricum, within the space of two months “gold went down one third in value throughout all Italy.” Such being the effect of a discovery of gold, it is evident that either the silver currency must undergo certain modifications in order that a definite round number of silver units may be equal to the gold unit, or on the other hand the gold unit must undergo modification. But as we have shown that the gold unit remained unaltered throughout all Hellas, Asia and Egypt down to the time of the Ptolemies, it follows that whatever changes were necessary must have taken place in the silver standards. Of this we have proof in the case of Rhodes itself. Down to 408 B.C. the three ancient cities of Ialysus, Camirus and Lindus issued each a separate series of coins, Camirus on the Aeginetic standard, the other two on the Phoenician. In 408 B.C. all these united in founding the new city of Rhodes, and henceforward there is a single coinage. At first the Attic standard seems to have been employed for silver, as rare tetradrachms of 260 grs. are found, but it must have very soon given place to the so-called Rhodian, the tetradrachm of which ranges from 240 to 230 grs. About the same time (400 B.C.) the Rhodians began to issue