Old World are no less invariably designated bronze, though in many cases thus taking for granted what analysis can alone determine. It is an error, however, that the later nomenclature of archæological periods has tended to strengthen: partly from the lack of appreciation of the importance of the argument in favour of the first use of the metals in a condition corresponding to the most primitive arts, and the discovery of scientific processes at later stages. This peculiar interest attaches to the metallurgy of the New World, that there all the earlier stages are clearly defined: the pure native metal, wrought by the hammer without the aid of fire; the melted and moulded copper; the alloyed bronze; and then the smelting, soldering, graving, and other processes resulting from accumulating experience and matured skill. But examples of British implements of pure copper have also been noted. In a valuable paper by Mr. J. A. Phillips, on the metals and alloys known to the ancients,[78] the results of analyses of thirty-seven ancient bronzes are given. Among these are included three swords, one from the Thames, the others from Ireland; a spear-head, two celts, and two axe-heads: all of types well-known among the weapons of the “Bronze Period.” Yet of the eight articles thus selected as examples of “bronze” weapons, one, the spear-head, proved on analysis to be of impure but unalloyed copper. Its composition is given as copper, 99·71; sulphur, ·28. In 1822, Sir David Brewster described a large battle-axe of pure copper, found at a depth of twenty feet in Ratho Bog, near Edinburgh, under circumstances scarcely less remarkable than some of the discoveries of works of art in the drift. The workmen dug down through nine feet of moss and seven feet of sand, before they came to the hard black till-clay; and at a depth of four feet in the clay the axe was found. The author accordingly remarks: “It must have been deposited along with the blue clay prior to the formation of the superincumbent stratum of sand, and must have existed before the diluvial operations by which that stratum was formed. This opinion of its antiquity is strongly confirmed by the peculiarity of its shape, and the nature of its composition.”[79] In 1850, my brother, Dr. George Wilson, undertook a series of analyses of ancient British bronzes for me, and out of seven specimens selected for experiment, one Scottish axe-head, rudely cast, apparently in sand, was of nearly pure copper.[80] Of eight specimens of metal implements selected for me by Mr. Thomas Ewbank, of New York, as examples of Peruvian bronze; four of them, on analysis, proved to be of unalloyed copper. The rich collections of the Royal Irish Academy furnish interesting confirmation of this idea of a transitional copper era. Dr. Wilde remarks, in his Catalogue of Antiquities, “Upon careful examination, it has been found that thirty of the rudest, and apparently