These facts will enable us to appreciate the comparison so often drawn between porcelain and jade. Thus, the Thang white made by Ho is said to have been “brilliant as jade,” and a contemporary was making vases of artificial jade. Again, in the Song Dynasty, a red porcelain was made at Ting-tcheou, decorated with flowers, graved, painted, or in relief, and said to resemble “sculptured red jade.” Coming down to the Siouen-te period of the Ming Dynasty (1426-1435), we again meet with cups “as white and brilliant as jade,” with their surfaces slightly punctured. These appear to have been imitated in the Wan-li period (1575-1619), when beautiful cups of the whiteness of jade figure in the altar services of the Emperor. The same description will apply to the porcelain of both periods. The glaze is likened to “a layer of congealed fat,” and has a pure ivory-like appearance and a soft unctuous touch, more nearly resembling that of French _pate tendre_ than any other modern ware. This feeling is heightened rather than diminished by the slight roughness, or rather, irregularity of the surface, such as might be caused by sinking minute grains in the glaze. Let us now see how far these comparisons with jade are warranted by the stone itself. Let it first be noted that many travellers bring from Canton a green and dark-green quality of chalcedony, under the impression that the wily merchants have given them genuine jade. There are also certain kinds of felspar, called nephrite, which have been mistakenly called jade. The genuine _yu_ varies in color from an ivory white to a dark green. It is very hard, very heavy, and fine in grain. Even after it is polished it has the appearance of wax, and the impression made upon the eye is confirmed by the smooth, greasy touch. The exceptional colors are red, black, orange, citron yellow, turquoise and a deeper blue. The white variety called, _par excellence_, Oriental jade, reflects a pure milky light nearly resembling that of the opal. Japan and India supply a quality of white with the faintest possible tinge of green. Another very beautiful variety is the “imperial jade,” or emerald green, which is occasionally found mixed with white, like the colors in agate. The value attached to jade was so great, that in China a special officer was appointed to take charge of the jade used in the personal decoration of the emperor, who wore several pieces attached to his girdle. Every description of jewel was made of jade, including those worn in the hair.