Page 476 - Oriental Series Japan and China, Brinkly

CHINA

that any influence should be ascribed to the soluble

salts obtained from them moreover certain passages
;

that treat of glazing material seem to show that it is

sometimes composed by mixing chalky earth to the

felspathic quartz which forms the basis of the glazing

matter. It is also explained that the mixture of

caustic lime and ashes is finely ground and washed

before being mixed with the petrosilex, the carbonised

film which the carbonic acid of the atmosphere forms

on the surface of the liquid being carefully removed

to be mixed with the petrosilex. This practice has

no other object than the production of a perfectly
Wepure lime.
are apparently given to understand

that it is the film of regenerated lime which con-

stitutes the useful element, and that the fern ashes

which sink to the bottom of the vessel in which the

washing is effected, are thrown away as of no value.
Whatever be the true action of the fern ashes, what-

ever be the real consequence of calcining the lime and

the ferns, judging only by the rough figures which- an-

alyses give, it is evident that the presence of the lime,

which enters in very minute quantities only into the
glaze of European porcelain, but which, on the con-

trary, is found in considerable proportions in the glaze

of Chinese porcelain sometimes as much as twenty-

five per cent by weight establishes a very salient dif-
ference between the two productions."

The conclusion of this eminent expert as to the

role played by lime does not seem to cover the whole

ground. He truly notes that the Japanese also
who indeed acquired the art of porcelain manufacture

from China added lime to their glazing material.
But he fails to note that the glazes of Japan could
never bear comparison with those of China in lustre,

390