in this change. But when Philip came to the throne he returned to the Phoenician standard for silver, and when for the first time in Macedon he issued a bountiful coinage of gold staters, they were struck on the ancient gold unit, the so-called Euboic standard of 130 grs. But hardly had Philip slept with his fathers, and Alexander reigned in his stead, when a need was felt for a change in the silver standard. Accordingly the latter in the early years of his reign began, and continued to his death, to strike his silver on the same standard as his gold. Let us now study the lessons to be learned from this history of currency. There can be no reasonable doubt that the ox-unit or stater was the unit by which gold was estimated from first to last in that region. Unless it already existed Philip would not have employed it for his gold coinage at a time when he was making changes in his silver, but would have assimilated his gold to his silver standard. But, as before remarked, just because gold was not coined anywhere in Greece until the closing years of the 5th century, and in all transactions it passed as bullion, so much the stronger was the reason for keeping its weight-unit unchanged. But was the standard of 220 grs. really an imported Phoenician, or was it not rather one arrived at in that region by the natives themselves owing to the relations then existing between silver and gold? It is evident from the account given of the Bisaltian silver mines that in the time preceding and immediately posterior to the Persian invasion silver was exceedingly abundant in all that region. It is then by no means unlikely that it required ten silver pieces of 220 grs. each to make the equivalent of one gold unit of 130 grs. With the exhaustion of the silver mines, and perhaps a greater output of gold, silver became dearer, and consequently 10 silver pieces of 170 grs. each were now equal to a gold stater. Abdera on the coast would come perfectly within the sphere of such changed conditions, and her standard would consequently likewise undergo modification. With Philip's accession, fresh conquests and a general development of resources may have temporarily thrown more silver on the market, thus inducing him to revert to the 220 grs. standard, but the exploiting of the famous mines of Crenides increased the supply of gold to such an
