The Cloisonné is the oldest variety; it is that in which the Greek or Byzantine enamels are made, and also the Chinese. In this method of enamelling the plate or metal foundation which is to receive the enamel is first cut to the required shape, and a little rim of gold ribbon soldered around it. The design is formed by narrow strips of gold ribbon or filigree, fastened to the foundation by a strong gum or cement, and bent to form the lines of the design. The cells thus formed are filled in with the enamel in a fine powdered state, or in a paste, the vitreous materials of the selected enamel having previously been tried, as to their colour and time required for perfect and equal fusion. The piece is then placed in a furnace or “muffle,” sufficiently open so that the progress of the fusing can be watched while firing, and withdrawn when perfectly fused. As the enamel generally sinks lower than the walls of the cells after fusion, it is necessary to add a second thin coating, or sometimes more, and to re-fire it in order to fill all the cavities. After this the work will require grinding down and polishing to level the surface and restore the brilliancy of the colours that may be slightly deadened by the cooling of the enamel. The materials of enamel colours are metallic oxides. These colours are finely pulverized, washed, and mixed with vitreous compounds, called fluxes, which are easily fusible, and in melting impart an extra brilliancy to the colours, and form with them by fusion the almost imperishable substance of enamel. The Champlevé enamels are made in the same way as the Cloisonné, with this exception, that instead of the thin gold ribbons or filigree work forming the design, the walls of the cells that compose the design and separate the enamel colours in the Champlevé variety are formed by the hollowing out of the thick metal—usually copper—and leaving the design to be formed out of the thin partitions that are left standing. The cavities are filled with the enamel mixtures and fused as in the Cloisonné method. On account of the articles being small, and also being mostly made on a gold foundation, they were more likely to have been stolen or melted down, and this accounts in a great measure for the scarcity of Cloisonné enamels in our collections. The Champlevé, on the other hand, being generally enamels on copper or brass, that from the cheapness of those materials, larger vessels and other objects were extensively made, and from both size and lesser value of the materials they were more likely to have escaped the melting-pot. When the foundation of the Champlevé enamels was copper, the lines of this metal that formed the design would be gilt with an amalgam of melted gold and mercury, and the piece re-fired at a lower temperature, in order not to injure or disturb the enamel surface.