Fragments of Græco-Roman pottery from Tarsus, lamps from the neighbourhood of Naples, and other examples of a highly glazed pottery from various antique sites which have all the appearance of a plumbeous composition, are preserved in many collections, as at the Louvre, Naples, the British museum, &c. The paste of which these examples are formed is to all appearance an ordinary potter’s clay, generally of a buff colour, and in no way similar in character to that of the Egyptian or Assyrian wares, glazed with a true glass. The adhesion of the vitreous coating to the surface, and its perfect adaptability to the irregularities of the shaped and moulded pieces, prove its affinity for the paste of which they are made, and indirectly that its composition is not the same as that of the Egyptian or Assyrian glaze. It is worthy of remark that nearly all these specimens are found in the south of Europe, examples rarely occurring even at Rome; and, indeed, it is not improbable that the use of this glaze had hardly been adopted by the artistic potters before their art, together with all others, had degenerated under the Lower Empire. The superabundance of the precious metals and other rich material, more appreciated by the powerful than the priceless treasures which art had formed from common clay, and which had been the delight of a more refined state of society, led finally to a total neglect of the higher branches of ceramic manufacture. It is not unlikely that plumbeous glaze may have been introduced by Greek or oriental potters into southern Italy. We learn from the monk Theophilus that the art of decorating fictile vessels with vitreous colours was practised by the Byzantine Greeks, who would have carried it there. This statement, in all probability, refers to the lead glazed wares and not to the tin enamel, the former of which, as we have seen, was known earlier than his time to the potters of Tarsus, Pompeii, &c., and it is reasonable to believe that the art may have been preserved in Byzantium when lost, or nearly lost, in Italy. Perhaps, in combination with incised ornament the use of this glaze never ceased in that country from the eighth and ninth centuries until the introduction or discovery of the stanniferous enamel in the fifteenth century; and we find that the earliest glazed wares of that country, the _sgraffiati_, the painted, and the _mezza maiolica_ wares, are covered with this description of vitreous surface.