The discovery of metal for the manufacture of implements marked a new epoch in the history of man. Copper was evidently known long before the discovery was made of using it with an alloy; but, owing to its softness, it could not supersede the use of stone. The question of whether there was, generally speaking, a Copper Age is still a matter of archæological controversy. The number of copper implements found is small, compared to the vast quantities of bronze of great variety that have been discovered. Flat copper celts have been found in Cyprus, the chief source of supply of the mineral to the Aegæan, in Hissarlik, in Hungary, Denmark, Sweden, France, Italy, and in Central India; but these latter are thought to be of late date, having been associated with objects of silver. The National Museum, Dublin, contains 84 copper celts, the collection having much increased since the compilation of Wilde’s _Catalogue_, when the number stood at 30. The number found in Ireland up to the present time is about 150; and specimens have been discovered in about half the counties and in all the provinces. The copper celts are of a primitive type, and were evidently modelled after those of stone. The smallness of the number may be due either to the probability of their being recast in the manufacture of tools and weapons on the discovery of bronze; or, that the metal proving soft, it was not largely used, being inferior in consistency to stone. Bronze celts have been found of a primitive character similar to the copper, so that they may have belonged to the same period of time. From this and other considerations it has been urged that a Copper Age did not exist in Western Europe, though such, no doubt, prevailed in the countries bordering on the Mediterranean, especially in Egypt. The latter country was in the Neolithic Age under the ‘New Race’; and copper came into use at the end of this Pre-dynastic Period. In all copper celts hitherto analysed in Ireland, a very small quantity of tin has been found, varying from about one per cent. to a mere trace. Whether the presence of tin in the copper is intentional or accidental is not definitely known; but it seems likely to have existed in the ore with other impurities.[92] Copper seems to have been in general use in Ireland; for, among other objects of this metal, awls, a halbert, and blades of knives have been discovered. The existence of native ore renders it likely that it was worked as soon as its properties were known; and this is supported by the fact that the word _umha_, the Irish name for copper, is pure Celtic. Tin exists in small quantities in Ireland, especially in the sand and gravel deposits of the Wicklow streams; but as to the method and means of mining, and how far it was carried on in those early days, we know nothing definite. Copper workings have been discovered, of a primitive type, in Cork and Kerry, containing stone implements among the refuse.