Painted enamels were not employed in the earliest times, but came to perfection in the Renaissance. A translucent enamel prevailed especially in Italy: a low relief was made with the graver on gold or silver; fine raised lines were left here and there, to separate the colours. Therefore, where the cutting was deepest, the enamel ran thicker, and consequently darker in colour, giving the effect of shading, while in reality only one tint had been used. The powdered and moistened enamel was spread evenly with a spatula over the whole surface, and allowed to stand in the kiln until it liquefied. Another form of enamel was used to colour gold work in relief, with a permanent coating of transparent colour. Sometimes this colour was applied in several coats, one upon another, and the features painted with a later touch. Much enamelled jewelry was made in this way, figures, dragons, and animal forms, being among the most familiar. But an actual enamel painting--on the principle of a picture, was rendered in still another way. In preparing the ground for enamel painting, there are two things which have been essentially considered in all times and countries. The enamel ground must be more fusible than the metal on which it is placed, or else both would melt together. Also the enamel with which the final decoration is executed must be more easily made fluid than the harder enamel on which it is laid. In fact, each coat must of necessity be a trifle more fusible than the preceding one. A very accurate knowledge is necessary to execute such a work, as will be readily understood. [Illustration: ENAMELLED GOLD BOOK COVER, SIENA] In examining historic examples of enamel, the curious oval set in gold, known as the Alfred Jewel, is among the first which come within our province. It was found in Somersetshire, and probably dates from about the year 878. It consists of an enamelled figure covered by a thick crystal, set in filigree, around the edge of which runs the inscription, "AELFRED MEC REHT GAVUR CAN" (Alfred ordered me to be wrought). King Alfred was a great patron of the arts. Of such Anglo-Saxon work, an ancient poem in the Exeter Book testifies: "For one a wondrous skill in goldsmith's art is provided Full oft he decorates and well adorns A powerful king's nobles." Celtic enamels are interesting, being usually set in the spaces among the rambling interlaces of this school of goldsmithing. The Cross of Cong is among the most famous specimens of this work, and also the bosses on the Ardagh Chalice.