We have no information as to the origin and development of blue and white porcelain in China, nor indeed do I know of any collection where an attempt has been made to classify the vast material. We must here content ourselves with a few notes which at best may indicate the ground on which such a classification should be made. We have seen (p. 75) that there is at least some presumptive evidence that the Chinese may have derived their knowledge of the use of cobalt (as a material to decorate the ground of their porcelain) from Western Asia, at a time when both China and Persia were governed by one family of Mongol khans. For we know now that in Syria or in Persia, in the twelfth or early in the thirteenth century, a rough but artistic ware was painted with a hasty decoration of cobalt blue and covered with a thick alkaline glaze; while in China, at that time, we have no evidence for the existence of any porcelain other than monochrome. It is possible that the earliest Chinese type of the under-glaze blue may be found in certain thick brownish crackle ware, decorated under the glaze, in blue, with a few strokes of the brush. Plates and dishes of this kind have been found in Borneo, associated with early types of celadon.[97] A similar ware, not necessarily of great antiquity, is often found in common use in the north of China and, I think, in Korea, and with it we may perhaps associate the greyish-yellow Ko yao decorated with patches of blue and white slip. It is very likely that there would be a strong opposition on the part of the Chinese literati to such a novel and exotic mode of decoration, but that such opposition would be less felt in the case of ware made for exportation, or it may be for use among the less conservative Mongols. We have an instance of a similar feeling in the protest that we know was made some two or three hundred years later against the application of coloured enamels to the surface of porcelain. Of the thousands of specimens of blue and white porcelain in our collections there is probably no single piece for which we can claim a date earlier than the fifteenth century. We can, however, distinguish two [Illustration: _PLATE XIX._ CHINESE BLUE AND WHITE WARE]