Page 58 - J. P Morgan Collection of Chinese Art and Porcelain

HISTORICAL INTRODUCTION

term employed to designate all kinds of pottery to
which an incipient vitrification has been imparted by

firing. This translucent pottery may be divided into

two classes: i. Hard paste, containing only natural
elements in the composition of the body and the glaze.
2. Soft paste, where the body is an artificial combina-
tion of various materials, agglomerated by the action
of fire, in which the compound called a frit has been

used as a substitute for a natural rock. No soft paste
porcelain, as here defined, has ever been made in

China, so that it need not be referred to further. All

Chinese porcelain is of the hard paste variety. The

—body consists essentially of two elements vi{., the

white clay, or kaolin, the unctuous and infusible ele-
ment, which gives plasticity to the paste, and the
felspathic stone, or petuntse, which is fusible at a high
temperature, and gives transparency to the porcelain.
Of the two Chinese names, which have become class-

ical since they were adopted in the dictionary of the

French Academy, kaolin is the name of a locality near

Ching-te-chen, where the best porcelain earth is mined,
petuntse, literally "white briquettes," refers to the
shape in which the finely pulverized porcelain stone
is brought to the potteries, after it has been submitted
to the preliminary processes of pounding and decan-
tation. The felspathic stone from Ch'i-men-hsien, in
the province of Kiangsu, has been chemically analyzed

by Ebelmen, who describes it as a white compact

rock of slightly grayish tinge, occurring in large frag-

ments, covered with manganese oxide in dendrites,
and having crystals of quartz imbedded in the mass,
which fuses completely into a white enamel under the

blowpipe.

In actual practice many other materials, such as

powdered quartz and crystallized sands, for example,
are added to the above two essential ingredients in the
preparation of the body of Chinese porcelain, which

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