But painted figures and embellishments are not the only ornaments by which the porcelain of the Chinese is dis tinguished. That celebrated and ingenious people stamp or imprint a great variety of figures on the surface of ves sels of white porcelain, though the surface be quite smooth and the vessels extremely thin. The mode in which this operation is performed is the following: A vase of the finest materials, and as thin as possible, is constructed; and when it has been polished on the wheel, both inside and out, they insert into it a stamp of nearly its own shape and dimensions, but cut with such figures as they wish the newly formed vase to assume. They next press down this stamp so firmly, that the moist vessel receives, in the most perfect way, the impression thus communicated; and if, in consequence of this pressure, the shape of the new ves sel be injured, they have merely to apply it to the wheel again to restore it. After having polished and finished it, as nearly as possible, the only other step is to cover it with in and without with the finest white varnish : and this var nish, while it occupies all the cavities which the stamp had made, and renders the surface perfectly smooth, gives, at the same time, a darkish hue and aspect to the figures in proportion to the quantity of it required in filling them up ; so that the whole device is as clearly seen, and as exquisitely shaded, as if the figures had been carefully painted on the outside. This method of stamping porce lain, though simple, has not yet been tried in Europe; nor has the following department of this art, though equally simple, been carried. on any where but in the east. The kind to which we allude, is the marbled porcelain, called by the Chinese tsou•tchi. The vase, after being formed, baked, and polished, is covered over, not with the common varnish, hut with a sort of coarse agates, calcin ed to a white powder, and separated front the grosser parts by means of water. The powder, reduced by water to about the consistence of cream, is the varnish used in this operation. And the great peculiarity of this kind of porcelain is, that this varnish does not spread over the vessel in equal portions, but runs in ridges and veins; thus forming, though accidentally, the most curious and romantic figures, and often exhibiting a species of mosaic work of the most exquisite kind; figures, which, instead of seeming the result of accident, appear to have been formed and elaborated by the most correct taste, and the highest ingenuity. Our crystal, it has been conjectured, would answer the same purpose as these coarse agates; and as the preparation is simple, the art could, without difficulty, be carried into execution in Europe. Of these vessels, the ground is generally white, though sometimes blue; and the only difference in the rCreparation is this, that the vessels require two coats, instead of one, of the agate oil, and that, before the second coat is applied, the blue colour must be imparted to them by immersing them in blue varnish.
In addition to painting, porcelain is frequently orna mented with gilding; a process performed in a way simi lar to painting. The. precipitate of gold, from its solution, is ground up with the oil of turpentine, and a small quan tity of the flux. With this preparation, the parts of the vessel to be gilt are covered ; and are in this state put into the furnace as in painting. The fire causes the oxygen to fly oft', the gold being left in its metallic form, firmly ad hering to the porcelain. It now requires merely to be varnished ; after which it assumes a rich, glossy, lively appearance. Platina is used in a similar way.
The only thing now that requires to be done with the porcelain, ere it be carried to the furnace; is oiling or varnishing; an operation of considerable delicacy, inas much as the varnish must be applied equally, and as if it exceed or fall under a certain quantity, the vessel is com pletely spoiled ; and this quantity must be great or small, according to circumstances; that is, according to the quality of the work, or their colour, or the colour of the figures and devices with which they are adorned. Of the
oils of which the Chinese make their varnish, we have already spoken. These oils they mix together with great caution and delicacy ; and, with an almost endless variety of other slight ingredients, form with them varnishes of every hue and every degree of fineness and elegance. The Chinese, though they have not for centuries made any real improvement in the art of porcelain manufacture, have recently discovered a new varnish, of a brown goldfish appearance ; much esteemed, probably on account of its novelty. This varnish is made of a common yellow earth, which they dissolve in water, and of which, allowing the coarsest residuum to be thrown out as refuse, they make use only of the purest and finest parts: This, which is first in the form of a soft paste, and which is afterwards dissolved by a new admixture of water, is mixed, before it can be used, with the common varnish, and other subordi nate ingredients, in just proportions. This varnish is ap plied by immersing the vessels in it; they arc then re moved to the oven ; and the baking gives the most beauti ful brightness to the colour.
After the porcelain has received, in the way described above, its proper shape, ornaments and colour, it requires only to be baked to complete the whole operation. The ovens, in which the baking takes place, are formed of three kinds of earth ; one yellow and common ; the re maining two scarce, one of them called lautou, a strong stiff earth, the other youtou, oily. These ovens are about two fathoms in height, and four in breadth, and their roof and wall are so thick and impervious, that even when the furnace is at the hottest, a person may place his hands on them with impunity, The dome or roof is shaped like a tunnel, with a large aperture at the top, and five smaller ones around, fo allow the smoke and flames to escape. in each of the furnaces there is a long vestibule or porch for conveying air, which answers instead of bellows. When the fire is lighted, every entrance to the furnace is closed, with the exception of this vestibule, and of a small aper ture of a foot in length, but very narrow, for the admission of wood, of which the fire is funned, and which two men, who release each other alternately, continue throwing in without intermission. Every piece of porcelain is inclos ed in a separate case, called in Europe saggars, ere it be put into the furnace. The bottom of these eases is cover ed with a layer of fine sand, which is sprinkled over with the powder of the kaolin, to prevent the sand from adher ing to the body of the vessel. These cases arc arranged in files, the bottom of the one forming the cover of the other, so that the porcelain may not he subjected to the too direct action of the heat. And the diflienIty at this step or the progress is, that they he so arranged, and the fire so managed, that the flame may have a free passage, and insinuate itself equally in every quarter of the furnace. To know when the porcelain is fully baked, the workmen open a small aperture, and with a pair or tongs take off one of the covers of the cases ; and if the colour of the porcelain exhibit a bright lustre, and if all the piles seem equally inflamed, the coction is regarded as sufficient ; and the fire being discontinued, the furnace is allowed to cool gradually before it is opened. Sonic species of porcelain are painted twice, and after having been in the oven just described, they are baked a second time in a smaller oven. Here they require no cases, the oven itself serving that purpose, being about a foot high and hall a foot broad ; and the object or this second baking (which takes place chiefly with teacups, and other similar elegatit vessels) is either to render the lustre of the colours more brilliant, or sometimes, by covering them with colours, to remove blemishes which have taken place in some former stage of the process. 1. • .