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_CHINA._
The name China, by which the ware that I am about to describe is known
in England, shows sufficiently the country from which we have received
it. The term porcelain, which is applied to it on the continent of
Europe, is Italian; _porcellana_ being in that language the name of
those univalve shells forming the genus _cypraea_ of the conchologist,
which have a high arched back like that of the hog (_porco_, Ital.),
and are remarkable for the white, smooth, vitreous glossiness of the
surface about the mouth of the shell, and sometimes, as in the common
cowry (_Cypraea moneta_), over the whole surface.
[3] By Mr. A. Aikin, in Trans. Soc. Arts.
The introduction of the Chinese porcelain soon excited a strong
desire in the various countries of Europe to imitate it; but as the
establishment of experimental manufactories for this purpose required
the expenditure of considerable sums, and at a risk beyond the means
of private persons, it is chiefly to the munificence of the sovereigns
of Europe that the public are indebted for the first steps made in
this interesting art. In Germany, chemists and mineralogists were set
to work; the latter to seek for the most appropriate raw materials,
and the former to purify and to combine them in the most advantageous
proportions. The French government adopted the very sensible plan of
instructing some of the Jesuit missionaries, who at that time had
penetrated to the court of China, and into most of the provinces
of that empire, to collect on the spot specimens of the materials
employed by the Chinese themselves, together with the particulars of
the process. The precise result thus obtained is not known; for as a
considerable rivalry existed between the different royal manufactories
of this ware, the most valuable information would of course be kept as
secret as possible.
Of the European manufactories of porcelain, that established at
Miessen, near Dresden, by Augustus Elector of Saxony and King of
Poland, in the early part of the 17th century, was the first that
aspired to a competition with the Chinese. In compactness of texture
and infusibility it was reckoned perfect a hundred years ago. It is
not quite so white as some of the French and English porcelains, but
is inferior to none in its painting, gilding, and other decorations.
The French royal manufactory at Sevrès, near Paris, has been for
several years in a gradually advancing state, with regard to the
whiteness, compactness, and infusibility of the body, the elegance of
the forms, the brilliancy of the colours, the elaborateness of the
drawing, and the superb enrichments of the gilding. The private
manufactories of porcelain in France imitate and approach more or less
near to the royal establishment.
At Berlin and at Vienna are royal porcelain manufactories in high
esteem, as well as in some of the smaller states of Germany.
_BRITISH PORCELAIN._
The first manufactories of porcelain in England were those at Bow, and
at Chelsea, near London. In these, however, nothing but soft porcelain
was made. This was a mixture of white clay and fine white sand from
Alum bay, in the Isle of Wight, to which such a proportion of pounded
glass was added as, without causing the ware to soften so as to
lose its form, would give it when exposed to a full red heat a
semi-transparency resembling that of the fine porcelain of China. The
Chelsea ware, besides bearing a very imperfect similarity in body to
the Chinese, admitted only of a very fusible lead glaze; and in the
taste of its patterns, and in the style of their execution, stood
as low perhaps as any on the list. The china works at Derby come, I
believe, the next in date; then those of Worcester, established in
1751: and the most modern are those of Coalport, in Shropshire; of the
neighbourhood of Newcastle, in Staffordshire, and in other parts of
that county.
The porcelain clay used at present in all the English works is
obtained in Cornwall, by pounding and washing over the gray
disintegrated granite which occurs in several parts of that county: by
this means the quartz and mica are got rid of, and the clay resulting
from the decomposition of the felspar is procured in the form of a
white, somewhat gritty powder. This clay is not fusible by the highest
heat of our furnaces, though the felspar, from the decomposition of
which it is derived, forms a spongy milk-white glass, or enamel, at
a low white heat. But felspar, when decomposed by the percolation of
water, while it forms a constituent of granite, loses the potash,
which is one of its ingredients to the amount of about 15 per cent,
and with it the fusibility that this latter substance imparts.
The siliceous ingredient is calcined flint; and in some of the
porcelain works, (particularly, I believe, those at Worcester,) the
soapstone from the Lizard-point, in Cornwall, is employed. These are
all the avowed materials; but there is little doubt that the alkalies,
or alkaline earths, either pure or in combination, are also used,
in order to dispose the other ingredients to assume that state of
semi-fusion characteristic of porcelain.
(The principal processes are) the grinding and due mixture of the
ingredients, in order to obtain a mass sufficiently plastic; the
forming this mass on the wheel; the subsequent drying of the ware;
the first firing, by which it is brought to the state of biscuit; the
application of the firmer colours occasionally on the surface of the
biscuit; the dipping the biscuit in the glaze; the second firing, by
which the glaze is vitrified; the pencilling in of the more tender
colours on the surface of the glaze; and the third and last firing
that is given to the porcelain.
It is not for me to determine which of our English porcelains is
the best; probably, indeed, one will be found superior in hardness,
another in whiteness, a third in the thinness and evenness of the
glaze, a fourth in the form of the articles, a fifth in the design,
and a sixth in the colours. In hardness and in fusibility, they are
probably all inferior to the Dresden and to the Sevres porcelain; for
pieces in biscuit and in white glaze, from both these manufactories,
are imported in considerable quantities, in order to be painted and
finished here. But it is equally certain, that the last ten years
have seen the commencement, and, in part, the completion, of such
improvements in this fabric, as will probably place the English
porcelains on an equality with the best of the continental European
ones.
Advantage has recently been taken of the semi-transparency of
porcelain biscuit to form it into plates, and to delineate upon it
some very beautiful copies of landscapes and other drawings, by so
adapting the various thicknesses of the plate as to produce, when held
between the eye and the light, the effects of light and shadow in
common drawings. The invention originated in the ingenuity of our
French neighbours.
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