DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.19574#0412
G L A 379
time, otherwife the colour will be loft; but by fo doing you will
have a very fair peach colour.
To make a gold yellow in Glass. Gold colour, being one of
the molt noble and fineft we can make, by reafon of its imita-
ting the moil perfect metal in nature, muft be made with the
pureft materials and greateft precaution.
Take two parts of cryftal frit, made with tarfo, and not with
fand, which is not fo good, and one part of frit, compofed of two
thirds of tarfo, and one third of fine fait of polverine prepared ;
pound and mix them well, and, to each fifty pounds of this com-
pofition, add half a pound of tartar purified, pounded, and fearced
fine, and half a pound of manganefs of Piedmont prepared, mix-
ing thefe powders well with the two frits, becaufe you muft not
caft them on the melted Glafs, as in other colours. Then put the
whole, by little and little, into a pot, and fet them in a furnace,
in which let them ftand at an ordinary fire four days, for fear the
Glafs riling fhould run over.
When that matter is well purified, you may ufe it for making
vefiels and what other works you pleafe, which will be of a fair
colour.
If you would have the colour yet clearer, you muft add more
powder, and you will have a very fine golden colour.
If you would have it yet finer, take fine cryftal frit, made of pol-
verine of rochetta, and the golden colour will be yet more fair.
To give Glass the colour of lapis lazuli. Lapis lazuli, which
is a fine blue, and full of veins of gold, will not be eafy to imi-
tate, without a great deal of care and induftry ifj its preparation.
To make this fine colour, you muft ufe the fame matter as
for the fine white; and, when it is in fufion in the pot, you
muft add to it, by little and little, the blue enamel in powder,
which is made ufe of by painters, mixing the whole well toge-
ther each time, and that as often as there is occafion to make
this colour.
Then try it, whether the colour is to your mind, and, when
it is, let it ftand for full two hours, and make a fecond efTay
of it; if the colour be perfect, let it ftand ten hours, and then
mix it again.
If it keeps in the fame ftate, without changing the colour,
you may employ it in making what veilels you pleafe, which
will be of the true colour of lapis lazuli.
If in working this Glafs it happens to rife, you may caft in a
Tittle leaf gold, which will make the Glafs approach yet nearer
to lapis lazuli, and which will in a moment ftop the rifing of
the metal, as fugar will do in boiling oil.
To make a milk-white colour in Glass. To make the milk-
white colour well requires no lefs exaclnefs than the blue.
To
time, otherwife the colour will be loft; but by fo doing you will
have a very fair peach colour.
To make a gold yellow in Glass. Gold colour, being one of
the molt noble and fineft we can make, by reafon of its imita-
ting the moil perfect metal in nature, muft be made with the
pureft materials and greateft precaution.
Take two parts of cryftal frit, made with tarfo, and not with
fand, which is not fo good, and one part of frit, compofed of two
thirds of tarfo, and one third of fine fait of polverine prepared ;
pound and mix them well, and, to each fifty pounds of this com-
pofition, add half a pound of tartar purified, pounded, and fearced
fine, and half a pound of manganefs of Piedmont prepared, mix-
ing thefe powders well with the two frits, becaufe you muft not
caft them on the melted Glafs, as in other colours. Then put the
whole, by little and little, into a pot, and fet them in a furnace,
in which let them ftand at an ordinary fire four days, for fear the
Glafs riling fhould run over.
When that matter is well purified, you may ufe it for making
vefiels and what other works you pleafe, which will be of a fair
colour.
If you would have the colour yet clearer, you muft add more
powder, and you will have a very fine golden colour.
If you would have it yet finer, take fine cryftal frit, made of pol-
verine of rochetta, and the golden colour will be yet more fair.
To give Glass the colour of lapis lazuli. Lapis lazuli, which
is a fine blue, and full of veins of gold, will not be eafy to imi-
tate, without a great deal of care and induftry ifj its preparation.
To make this fine colour, you muft ufe the fame matter as
for the fine white; and, when it is in fufion in the pot, you
muft add to it, by little and little, the blue enamel in powder,
which is made ufe of by painters, mixing the whole well toge-
ther each time, and that as often as there is occafion to make
this colour.
Then try it, whether the colour is to your mind, and, when
it is, let it ftand for full two hours, and make a fecond efTay
of it; if the colour be perfect, let it ftand ten hours, and then
mix it again.
If it keeps in the fame ftate, without changing the colour,
you may employ it in making what veilels you pleafe, which
will be of the true colour of lapis lazuli.
If in working this Glafs it happens to rife, you may caft in a
Tittle leaf gold, which will make the Glafs approach yet nearer
to lapis lazuli, and which will in a moment ftop the rifing of
the metal, as fugar will do in boiling oil.
To make a milk-white colour in Glass. To make the milk-
white colour well requires no lefs exaclnefs than the blue.
To