Porcelain

by Edward Dillon

We have already seen that much depends upon the period of the firing at which the glaze becomes liquid or soft, and upon the exact degree of fluidity attained by it. Should the oxidising currents be allowed further play at the critical period of the firing, the blue and greenish stains and splashes will become more predominant, and we may either pass over to the flambé or ‘transmutation’ glazes, or finally the glaze may become almost white and transparent.

But we must hark back to the wares of the Sung period, to the Chün yao, to find the origin of these variegated glazes. These early Sung glazes were copied in the time of Yung-cheng, and if we are to believe the contemporary list, already quoted, of the objects copied, they were of a very complicated nature. In this class of flambé ware we must include also a large part of the so-called Yuan tsu ([see page 77]), a heavy kaolinic stoneware, certainly not all dating from the Yuan or Mongol period—a ware, indeed, still common in the north of China. This ware is roughly covered with a glaze of predominant lavender tint, speckled with red, and thus approaches to the ‘robin’s egg’ glaze of the American collector, though this latter is found on a finer porcelain of later times.

Another name which has been used to include many of these variegated glazes is Yao-pien or ‘furnace-transmutation.’ This last word very well expresses the process by which the colour is developed, but it must be remembered that this is not exactly the meaning that the word yao-pien conveys to the Chinese mind.[94] With this term the happy accidents of the furnace were linked by the Père D’Entrecolles: he tells us that it was proposed to make a sacrificial red, but that the vase came from the furnace like a kind of agate. Dr. Bushell thinks that most of the fine pieces of this ware date from the time of Yung-cheng and Kien-lung (1722-1795), and he is of opinion that they were prepared by a soufflé process rather than by any ‘academic transformation’ of a copper-red glaze. ‘The piece,’ he says, ‘coated with a greyish crackle glaze or with a ferruginous enamel of yellowish-brown tone, has the transmutation glaze applied at the same time as a kind of overcoat. It is put on with the brush in various ways, in thick dashes not completely covering the surface of the piece, or flecked as with the point of the brush in a rain of drops. The piece is finally fired in a reducing atmosphere, and the air, let in at the critical moment when the materials are fully fused, imparts atoms of oxygen to the copper and speckles the red base with points of green and turquoise blue’ (Oriental Ceramic Art, pp. 516-17). Some practical experiments lately made in France would tend to show that the critical moment should be placed a little earlier, before the glaze is completely fused, for after that point is reached the surrounding atmosphere has little influence upon the metallic oxides in the glaze. It is to this capricious action of the furnace gases that are due those wonderful effects that may be observed in looking into these glazes, curdled masses of strange shapes and varying colour suspended in a more or less transparent medium, and assuming at times those textures resembling animal tissues which are graphically described by the Chinese as pig’s liver or mule’s lungs. It must be understood that into many of the more modern and apprêtés specimens of flambé ware the sources of the violent contrasts of colour are found not only in the oxides of copper and iron, but in those of cobalt and manganese also.

But in contrast to ‘the stern delights’ of these flamboyant wares there is another kind of glaze, chemically closely allied, for it is also of transmutation copper origin, of which the associations are of another kind. This is the peach-bloom, the ‘apple-red and green,’ or again the ‘kidney-bean’ glaze of the Chinese. Although claiming an origin from Ming times, this glaze is always associated with the great viceroy Tsang Ying-hsuan. The little vases and water-vessels of a pale pinkish red, more or less mottled and varying in intensity, are highly prized by Chinese collectors.

Decoration with Slip.—There is a class of ware which might perhaps claim a separate division for itself—I mean that decorated with an engobe or slip. We have already mentioned the most important cases where this engobe is applied to the surface of single-glazed wares: these are, in the first place, the fond laque ([Pl. xvi].), and in a less degree certain blue and even white wares. The slip, of a cream-like consistency, is as a rule painted on with a brush over the glaze, generally, I think, after a preliminary firing.[95] This engobe may then itself be decorated with colours, as we have seen in the case of the Ko yao, and the whole surface probably then covered with a second glaze.[96] Sometimes when the ground itself is nearly white we get an effect like the bianco sopra bianco of Italian majolica. This carefully prepared and finely ground engobe contains, in some cases at least, the same materials as those employed in the preparation of the Sha-tai or ‘sand-bodied’ porcelain.

Pierced or Open-work Decoration ([Pl. xviii]. 1).—We may here find place for another kind of decoration, one much admired in Europe in the eighteenth century.

PLATE XVIII. 1—CHINESE, PIERCED WARE, BLUE AND WHITE
2—CHINESE, BLUE AND WHITE WARE

This is obtained by piercing the paste so as to form an open-work design, generally some simple diapered or key pattern, but sometimes flowers or figures of cranes. The little apertures or windows thus formed may be filled in by the glaze (if this is sufficiently viscous to stretch across them) in the simple process of dipping. In this case the glaze takes in part the place of the paste, and indeed in the closely allied ‘Gombroon’ ware of Persia it is the thick, viscous glaze rather than the friable sandy paste that holds the vessel together. It is the plain white ware to which this decoration is generally applied in China. There is one class where this pierced work is associated with groups of little figures, in biscuit, in high or full relief—as is well illustrated by a series of small cups in the Salting collection, some of which bear traces of gilding and colours.