“The desire of rendering terra-cotta less porous, and of producing vases capable of retaining liquids, gave rise to the covering it with a vitreous enamel or glaze. The invention of glass has been hitherto generally attributed to the Phœnicians; but opaque glasses or enamels, as old as the eighteenth dynasty, and enamelled objects as early as the fourth (B.C. 3000-2000), have been found in Egypt. The employment of copper to produce a brilliant blue-colored enamel was very early both in Babylonia and Assyria, but the use of tin for a white enamel, as recently discovered in the enamelled bricks and vases of Babylonia and Assyria, anticipated by many centuries the rediscovery of that process in Europe in the fifteenth century, and shows the early application of metallic oxides. This invention apparently remained for many centuries a secret among the Eastern nations only, enamelled terra-cotta and glass forming articles of commercial export from Egypt and Phœnicia to every part of the Mediterranean. Among the Egyptians and Assyrians enamelling was used more frequently than glazing, and their works are consequently a kind of faience, consisting of a loose frit or body, to which an enamel adheres after only a slight fusion. After the fall of the Roman Empire the art of enamelling terra-cotta disappeared among the Arab and Moorish races, who had retained a traditional knowledge of the process. The application of a transparent vitreous coating, or glaze, over the entire surface, like the varnish of a picture, is also referable to a high antiquity, and was universally adopted either to enhance the beauty of single colors or to promote the combination of many. Innumerable fragments and remains of glazed vases, fabricated by the Greeks and Romans, not only prove the early use of glazing, but also exhibit, in the present day, many of the noblest efforts of the potter’s art.” The use of oxides is also very ancient. The Egyptians employed that of copper for the production of their turquoise-blue, and possibly also for their green, manganese for violet, iron or silver for yellows, etc. The same processes were known in Babylon and Assyria. To the Persians and Arabians the application of metallic lustres was known at a very early period. Plumbiferous, or lead-glaze, was employed by the Babylonians, and the knowledge of its composition was in all probability imported thence among the Greeks, and by them may have been carried into Southern Italy. The course of enamel is equally difficult of definition. Although used in Egypt, Babylon, and Assyria, it does not appear to have supplanted the lead-glaze; and for a long period all traces of it are lost, until it reappeared among the Arabs. We next meet with it as a distinctive characteristic of the potteries of Spain. It was also known to the Saracenic and Moorish potters of Sicily, and from either of these sources may have found its way into Italy. CHAPTER IV. MANUFACTURE AND DECORATION.