DOI Page / Citation link:
https://doi.org/10.11588/diglit.19574#0284
EME 259
When this is all in, make a proof of the metai, and, if it have
any bluifhnefs, add more crocus martis, a fmall quantity at a
time. When the whole is of a fine leek-green, let it ftand twen-
ty-four hours to mix thoroughly, and then work it. Neri's Art
ofGlafs, p. 5L
When it is grown cold, break the crucible, and you will find
within a matter of the colour of a very find Emerald ; which, if
fet in gold, will furpafs, in beauty, the true oriental Emerald.
If it happens that your matter is not enough refined and pu-
rified, you muft fet it in again the fecond time into the fame fur-
nace, where it will be purified as much as it need to be ; which
may be known by lifting up the cover, if the matter appears
Alining.
If it is notfo, lute the cover on again, and put the whole into
the furnace.
You may obferve this once for all, that you muft not break
the crucible before the matter is thoroughly baked and purified ;
for, if you do, 6and fo are obliged to put the matter into another
crucible, the paffe will be painted and full of blifters.
If you cannot eafily have the conveniency of ufing a potter's
furnace, you may make one yourfelf with a little charge, wherein
you may put twenty crucibles at once, each of different colours ;
fo one baking may ferve for a great deal of matter.
You muft make ufe of hard wood to dry and heat the furnace,
as is alfo directed in the baking of glafc, and continue the fire
twenty-four hours, in which time the matters ought to be baked
and purified enough; but, for more furety, you may continue
the fire fix hours longer, and they will be certainly baked enough.
The matter being thus rightly baked, you may have it po-
lifhed at the wheel, and fet it in a foil in gold, as is done with
true gems, and you will have an Emerald Brighter than the ori-
ental.
Another deeper Emerald Colour. That which makes Eme-
rald deeper than the precedent, proceeds from the fmaller quan-
tity of cryftal employed in it, with more of the other materials,
which make it indeed more fair, but at the fame time more
brittle.
You muft bake it at leaft fix hours longer than the preceding,
to take away that imperfection, which lead ufually gives.
The dofe of this pafte is, one ounce of natural cryftal pre-
pared, fix ounces and an half of red lead, feventy-five grains of
verdigreafe, ten grains of crocus martis made with vinegar; the
whole pulverifed and well mixed together. Then proceed as di-
rected in the article preceding j only let the matter ftand longer
in the fire, and you will hfve an admirable oriental Emerald co-
S 2 lour,
When this is all in, make a proof of the metai, and, if it have
any bluifhnefs, add more crocus martis, a fmall quantity at a
time. When the whole is of a fine leek-green, let it ftand twen-
ty-four hours to mix thoroughly, and then work it. Neri's Art
ofGlafs, p. 5L
When it is grown cold, break the crucible, and you will find
within a matter of the colour of a very find Emerald ; which, if
fet in gold, will furpafs, in beauty, the true oriental Emerald.
If it happens that your matter is not enough refined and pu-
rified, you muft fet it in again the fecond time into the fame fur-
nace, where it will be purified as much as it need to be ; which
may be known by lifting up the cover, if the matter appears
Alining.
If it is notfo, lute the cover on again, and put the whole into
the furnace.
You may obferve this once for all, that you muft not break
the crucible before the matter is thoroughly baked and purified ;
for, if you do, 6and fo are obliged to put the matter into another
crucible, the paffe will be painted and full of blifters.
If you cannot eafily have the conveniency of ufing a potter's
furnace, you may make one yourfelf with a little charge, wherein
you may put twenty crucibles at once, each of different colours ;
fo one baking may ferve for a great deal of matter.
You muft make ufe of hard wood to dry and heat the furnace,
as is alfo directed in the baking of glafc, and continue the fire
twenty-four hours, in which time the matters ought to be baked
and purified enough; but, for more furety, you may continue
the fire fix hours longer, and they will be certainly baked enough.
The matter being thus rightly baked, you may have it po-
lifhed at the wheel, and fet it in a foil in gold, as is done with
true gems, and you will have an Emerald Brighter than the ori-
ental.
Another deeper Emerald Colour. That which makes Eme-
rald deeper than the precedent, proceeds from the fmaller quan-
tity of cryftal employed in it, with more of the other materials,
which make it indeed more fair, but at the fame time more
brittle.
You muft bake it at leaft fix hours longer than the preceding,
to take away that imperfection, which lead ufually gives.
The dofe of this pafte is, one ounce of natural cryftal pre-
pared, fix ounces and an half of red lead, feventy-five grains of
verdigreafe, ten grains of crocus martis made with vinegar; the
whole pulverifed and well mixed together. Then proceed as di-
rected in the article preceding j only let the matter ftand longer
in the fire, and you will hfve an admirable oriental Emerald co-
S 2 lour,