I now for the first time have to treat of the decoration of glass by enamel painting. It may be as well here to explain that in a true enamel, as the term is used in ceramic and vitreous art, the coloured decoration is applied to the glassy surface (either glaze or glass body) in the form of a pigment worked up with water or other liquid. Such enamel paints are composed, in later times at least, of a base of silicate of lead (the flux), coloured by various metallic oxides. It is essential that these enamels should be more fusible than the body on which they are painted, so that when subjected to the heat of the muffle-fire they may be completely fused, while the glass or glaze on which they rest is not more than superficially softened. Such enamel decoration, whether on porcelain or on glass, may vary from a mere wash of colour on the one hand, of which it is sometimes difficult to say whether it has ever been subjected to the heat of the muffle-fire, to a true vitreous covering on the other, where the various colours stand out in relief like so many jewels. I may say at once that the Romans, as far as we know, never attained to any great success in this method of decoration. Its full development was reserved for the Saracens of the thirteenth and fourteenth centuries. This is indeed the one important advance made in the artistic manipulation of glass since ‘the palmy days of Rome.’ Not but that the Romans, and probably to some extent the Phœnicians and the Alexandrian Greeks before them, did not draw and paint upon their glass; but if we may judge from the rare and fragmentary examples that have survived, they were unable to obtain much decorative effect by this means; again, the very poverty and the paint-like quality of such enamels as they used, have doubtless in many cases led to their total disappearance from the surface of the glass.[36] The painting on the cup-like lids of the little bowls from Cyprus I have already mentioned. On a few fragments of thin glass from Egypt, draped figures have been painted in opaque colours. Perhaps the nearest approach to an effective use of enamel colours may be seen on two little cups found in graves of the fourth century at Varpelev, in Denmark. These Scandinavian tombs have yielded many interesting pieces of glass, as well as some bronze vessels—possibly booty brought home from marauding expeditions. The designs on these cups (they are illustrated in the _Proceedings of the Copenhagen Antiquarian Society_, 1861) are thus described by Mr. Nesbitt: ‘On the larger one are a lion and a bull, on the lesser two birds with grapes.... The colours are vitrified and slightly in relief—green, blue, and brown may be distinguished.’ (_Slade Catalogue_, p. xvi. See also some account of glass from these and other Scandinavian tombs in Montelius and Reinach, _Les temps préhistoriques en Suède_.)