CERAMIC ART IN CHINA. 359 



Chinese term it, to give it "bone;"" the other, fusible, the glaze {glag- 

 iire, eouve?'te), which imparts its characteristic transparency to porce- 

 lain and at the same time prevents the vessel retaining its porousness 

 or contracting under the influence of heat. 



The principal ingredients of the paste are clays, which are classed 

 according to their greater or less degree at the same time of plasticity 

 and fusibility. The porcelain clay jxw excellence is kaolin, a white 

 aluminum silicate produced by the decomposition of granitic or felds- 

 pathic rocks, almost infusible, and if not always perfectl}" white by 

 nature, losing its tint in the kiln. It derives its name originall}' from 

 that of the hill whence the manufactories at Chingte-chen procured 

 their supph' of this clay. The main object of the glaze is, as has 

 been said, while securing transparency, to prevent the paste remaining 

 porous. Now, the substances unafl^ected by water but fusible by fire 

 are quartz, silica, certain limestones, pegmatite, feldspar, silex, and 

 the compounds resulting from a superficial fusion of these substances, 

 which are then reduced to a fine powder. The relative proportion of 

 these substances in the composition of the glaze maj- be raised at will 

 with a corresponding diversity of result — M. Brogniart dividing the 

 compound into three classes, each subdivided into three groups. 



Inordinary language porcelain is classified under two grand divisions, 

 hard paste and soft paste — la jMte dure and la pate teyxdre. The latter is 

 characterized by the presence, either naturally or artificiall}- ,of limestone 

 products or alkalies, either in the condition of phosphates or in that of 

 marl or chalk,which lower its degree of fusibilit\', so that it becomes fus- 

 ible or at least soft at a temperature of 800° C. The absence of these 

 matters in the hard paste causes it to retain its original consistency in 

 far greater heat, and it can resist a temperature of 1,500° C, or above. 

 Upon these two divisions are grafted several minor ones determined 

 by the kind of glaze, which, according to its composition and mode of 

 application, is termed vernis, email, or couverte. After unglazed tiles 

 and bricks, the primitive thin glaze, vernis, \f> found on the pottery of the 

 Etruscans, ancient Arabs, Persians, and the early inhabitants of 

 America; then, on that manufactured in Germany and Italy in the 

 fourteenth century, a sort of transparent glass with a foundation of 

 lead — a glaze still common in country productions. Later, in the 

 fifteenth century, the true white enamel, email, a mixture of salt, of 

 lead and tin, the thickness of which concealed the color of the paste, 

 was discovered in Italy and gained immortality for Luca della Robl)ia, 

 of Florence, and Oragio Fontana, of Pesaro. In this category" also 

 belong the majolicas, faenza, the faiences of Niirnberg, Bernard 

 Palissy's pottery, the faiences of Nevers, Rouen, and other places, 

 ancient and modern. The couverte is confined to porcelain proper. 



Crude Chinese kaolin, when cleansed by washing out its impurities, 

 and ready for use in making the paste, gives a ver3' white clay, soft to 



