DOI Page / Citation link:
https://doi.org/10.11588/diglit.19571#0166
i52 THE ARTIST'S ASSISTANT.
reduced to a fine powder: for in a groffer Mate, every
degree of finenefs renders it fo different, that adjudg-
ment cannot be eafdv formed of it. Smalt is to be
had of all colourmen. and is not fubjeft to any adul-
terations, which would not be obvious on infpeciion.
Gold is ufed in enamel to produce a crimfon or
ruby colour ; which, bv the miftaken lenfe of the
Latin word purpurcus, has been called purple by all
the Englifh and French writers. It muft be previ-
oufly reduced to the ftate of a precipitated powder,
by diffolving in aqua regia : and making a precipi-
tation by means of tin, fixt alkaline fait, or fome
other metallic, or alkaline body.
Silver is ufed for producing a yellow colour in
enamel. It muft be previoufly reduced to the ftate
of a powder ; which may be done either bv pre-
cipitation from fpirit of nitre, or by calcination
with fulphur. The precipitation of filver from fpi-
rit of nitre, may be performed by diffolving an ounce
of fdver, in two or three ounces of fpirit of nitre ;
and precipitating and edulcorating it.
Copper is ufed in enamel painting, for the form-
ing, green, blue, and red colours; but it muft be
previoufly either calcined, or reduced to the ftate of
a powder by precipitation.
Iron is ufed to produce on orange red, or foul
fcarlet colour in enamel ; as alio a tranfparent yel-
low; and to a flirt, likewife, in the formation of
greens, and other compound colours. It is prepared
many ways, both bv corrofion and precipitation ;
fome of which indeed make a real difference, but
moft of them lead to the fame end.
Antimony is ufed for producing a yellow colour
in enamel, as well as the white before mentioned;
and
reduced to a fine powder: for in a groffer Mate, every
degree of finenefs renders it fo different, that adjudg-
ment cannot be eafdv formed of it. Smalt is to be
had of all colourmen. and is not fubjeft to any adul-
terations, which would not be obvious on infpeciion.
Gold is ufed in enamel to produce a crimfon or
ruby colour ; which, bv the miftaken lenfe of the
Latin word purpurcus, has been called purple by all
the Englifh and French writers. It muft be previ-
oufly reduced to the ftate of a precipitated powder,
by diffolving in aqua regia : and making a precipi-
tation by means of tin, fixt alkaline fait, or fome
other metallic, or alkaline body.
Silver is ufed for producing a yellow colour in
enamel. It muft be previoufly reduced to the ftate
of a powder ; which may be done either bv pre-
cipitation from fpirit of nitre, or by calcination
with fulphur. The precipitation of filver from fpi-
rit of nitre, may be performed by diffolving an ounce
of fdver, in two or three ounces of fpirit of nitre ;
and precipitating and edulcorating it.
Copper is ufed in enamel painting, for the form-
ing, green, blue, and red colours; but it muft be
previoufly either calcined, or reduced to the ftate of
a powder by precipitation.
Iron is ufed to produce on orange red, or foul
fcarlet colour in enamel ; as alio a tranfparent yel-
low; and to a flirt, likewife, in the formation of
greens, and other compound colours. It is prepared
many ways, both bv corrofion and precipitation ;
fome of which indeed make a real difference, but
moft of them lead to the fame end.
Antimony is ufed for producing a yellow colour
in enamel, as well as the white before mentioned;
and