Most of the green glazes are low fired, melting in the temperature of the _demi-grand feu_ and the muffle kiln. The high-fired greens are those of celadon class. There is the _lang yao_[340] green, which has been discussed under that heading, a crackled glaze, in colour intermediate between apple green and the sea green celadon, and with a surface texture hazy with bubbles like the _sang de bœuf_, to which it is a near relation. This soft and beautiful colour has been described as a “copper celadon,” and though Dr. Bushell refuses his blessing on the name it seems to me a particularly happy expression. For the colour apparently results from the same copper medium which under slightly different firing conditions produces the _sang de bœuf_ red and at the same time its tint approaches very nearly to the typical celadon green. The true celadon glaze was freely employed on the early Ch’ing porcelains, especially on those of K’ang Hsi and Yung Chêng periods. It is a beautiful pale olive or sea green colour, made light by the pure white porcelain beneath which its transparent nature permits to shine through. Compared with the Sung celadons as we know them,[341] the Ch’ing dynasty ware is thinner in material and glaze, wanting in the peculiar solidity of appearance of the ancient wares; the body is whiter and finer, and the base is usually white with the ordinary porcelain glaze. There is, moreover, no “brown mouth and iron foot,” unless indeed this feature has been deliberately added by means of a dressing of ferruginous clay, a make-up which is too obvious to deceive the initiated. There were, however, some careful imitations of the ancient celadons made at this time and got up with the appearance of antiquity, but these were exceptional productions.[342]