Page 495 - Oriental Series Japan and China, Brinkly

MANUFACTURING PROCESSES

only of red or brown strokes applied to fragments of

white coloured glass.
"
regard to the thickness of the colours
Having

employed and yet to the lack of intensity, is many

cases, of the tone obtained, one is led to conclude

that these colours, compared with our own, contained

but a small proportion of the principal colouring

matters. The conclusion has been fully verified by

experiments. They prove that the colours by means

of which the Chinese obtained such remarkable

results, in respect of brilliancy and harmony of deco-

rative effect, had much more analogy with the vitri-

fied substances known as enamels than with anything

else.

" Whatever be the origin of the colours used for

the decoration of porcelain in China, they all present,

simultaneously with great simplicity, a character of

similarity which cannot escape attention. The flux,

which is not distinct in the colour, is always composed

of silica, of oxide of lead in proportions somewhat

variable, and of a greater or less quantity of alkalies

(soda and potash). This flux retains, in a liquefied

state, as silicates, some hundreths only of colouring

oxides : heir number , is exceedingly limited. The

colouring matters are, oxide of copper for greens and

bluish greens ; gold for reds oxide of cobalt for
;

blues oxide of antimony for yellows ; arsenical acid
;

and stannic acid for whites. Oxide of iron and

oxides of impure manganese (which give, one a red,

the other a black) constitute the only exception,
doubtless because it is impossible to obtain these

colours by the process of liquefaction from the oxides
mentioned above.

" This special composition of the colours used in

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