The interest which attaches to the determination of the extent and probable date of the first intercourse of the Britons with traders from the far east, has led to the anticipation of some points not strictly belonging to the present section of our inquiry. This question of the existence of a native coinage, or of the substitution of a foreign metallic currency for the rude process of barter, at a period prior to the introduction of Roman customs by the legionaries of the first and second centuries, well merits the careful study it is now receiving, since no other evidence could furnish equally satisfactory proof of early progress in social civilisation. It cannot admit of doubt, however, that long before even the Greek or Phœnician trader had taught the Cornish miner this ingenious substitute for a direct exchange of commodities, he had learned to fuse and work the rich veins of ore with which his native soil abounded, and to fashion them into a variety of personal ornaments as well as of weapons and implements. The Phœnician sought his tin in order to mix it with the copper which he already possessed, and thereby to produce bronze weapons combining the ductility of copper with that indispensable hardness which could alone fit them to supersede the older implements of stone. How early this interchange first took place, it appears now altogether vain to inquire. The evidence already adduced, however, is at least sufficient to justify us in assigning to it a very remote period, while the more abundant and far more useful metal, iron, was little known even to the oldest nations along the Mediterranean coasts. Worsaae remarks, "There are geological reasons for believing that the Bronze Period must have prevailed in Denmark five or six hundred years before the birth of Christ."[239] Denmark, however, had all its metal to import, while the earliest historic allusion to England represents her exporting her abundant metallic ores, and bartering them with the southern merchant for the productions of his superior skill. The metallic riches of England have not escaped the attention of the intelligent Danish archæologist:--"It is highly probable," he remarks, "that the ancient bronze, formed of copper and tin, was diffused from one spot over the whole of Europe; which spot may be supposed to be England, because, not to mention the quantity of copper which that country produces, its rich tin mines have been known from the earliest historic periods to the nations of the south, while in the other parts of Europe there occur only very few and doubtful remains of far less important tin mines which we are justified in believing to have been worked at that time."[240]