DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.19574#0082
68 BRA
mixture of gold, filver, and copper. L. Mummius having fackei
and burnt the city of Corinth, 146 years before our Saviour's
time, there being there a vafi number of flatues, images, velTels,
&c. of gold, filver, and copper, all thefe melted and run toge-
ther, by means of the violence of the conflagration; and this mix-
ture was the compofitir n called Corinthian Brafs. Thofe who
fpeak of it accurately, diftinguifh it into three kinds ; in the firft,
gold is the prevailing metal; in the fecond, filver j in the third,
gold, filver, and copper are equally blended.
To ckanfe Brass. Take aqua-fortis and water, of each a
like quantity ; fhake them together, and, with a woollen rag
dipped therein, rub it over; then, prefently rub it with an oily
cloth : Laftly, with a dry woollen cloth, dipped in lapis cala-
minaris, and it will be as clear and bright as when new.
To purge Brass. It is cleanfed or purged by carting into it,
while it is melted, broken glafs, tartar, fal-armoniac, andfalt-
petre, each of them by turns, a little and a little.
To calcine Brass, called Orpello or Tremolante, making a cu-
rious fea-green or fky-colour. Take thin Brafs, cut it into fmall
pieces, put it into a crucible covered and luted at top ; fet it in
a fierce fire, where let it ftand four days in a great, but not
melting fire, for, if it melt, your labour is loft. In four days
time it will be very well calcined ; then powder it as fine as you
poffibly can, fearfe it, and the powder will be black ; fpread this
on tiles, and keep it on a leer on burning coals for four days,
rtear to the round hole ; take away the afhes that fall upon it,
powder and fearfe it again, and then keep it clofe flopped for ufe.
To know if it be well calcined, put it into glafs, and, if it
fwells, it is rrght; if not, it is not well calcined, or elfe it is
over burnt; and, if fo, it will not give a good colour.
To calcine Brass, fo as to make a tranfparent red. Cut your
thin pieces of Brafs fmall, and put it into a melting-pot, with
layers of powder of brimftone, and metal, as in copper. Set
it firft on kindled coals, then put it into a ftrong fire in the fur-
nace, to calcine for twenty-four hours; then beat it to a fine
powder, and fearfe it; put it covered into the furnace, on
earthen tiles, for twelve days, to reverberate ; fo powder, grind,
and keep it for ufe.
Befides a red, it contributes principally to the making a yel-
low and chalcedony.
A red colour fro?n Brass. Put fmall pieces of it into the
arches of the furnace, and let them remain there clofe till they
are well calcined; but in fuch a fire, that they may not melt;
and, when they are well calcined, powder the Brafs, and the
powder will be red, and excellent, in many uies, for colouring
glafs.
b Tte
mixture of gold, filver, and copper. L. Mummius having fackei
and burnt the city of Corinth, 146 years before our Saviour's
time, there being there a vafi number of flatues, images, velTels,
&c. of gold, filver, and copper, all thefe melted and run toge-
ther, by means of the violence of the conflagration; and this mix-
ture was the compofitir n called Corinthian Brafs. Thofe who
fpeak of it accurately, diftinguifh it into three kinds ; in the firft,
gold is the prevailing metal; in the fecond, filver j in the third,
gold, filver, and copper are equally blended.
To ckanfe Brass. Take aqua-fortis and water, of each a
like quantity ; fhake them together, and, with a woollen rag
dipped therein, rub it over; then, prefently rub it with an oily
cloth : Laftly, with a dry woollen cloth, dipped in lapis cala-
minaris, and it will be as clear and bright as when new.
To purge Brass. It is cleanfed or purged by carting into it,
while it is melted, broken glafs, tartar, fal-armoniac, andfalt-
petre, each of them by turns, a little and a little.
To calcine Brass, called Orpello or Tremolante, making a cu-
rious fea-green or fky-colour. Take thin Brafs, cut it into fmall
pieces, put it into a crucible covered and luted at top ; fet it in
a fierce fire, where let it ftand four days in a great, but not
melting fire, for, if it melt, your labour is loft. In four days
time it will be very well calcined ; then powder it as fine as you
poffibly can, fearfe it, and the powder will be black ; fpread this
on tiles, and keep it on a leer on burning coals for four days,
rtear to the round hole ; take away the afhes that fall upon it,
powder and fearfe it again, and then keep it clofe flopped for ufe.
To know if it be well calcined, put it into glafs, and, if it
fwells, it is rrght; if not, it is not well calcined, or elfe it is
over burnt; and, if fo, it will not give a good colour.
To calcine Brass, fo as to make a tranfparent red. Cut your
thin pieces of Brafs fmall, and put it into a melting-pot, with
layers of powder of brimftone, and metal, as in copper. Set
it firft on kindled coals, then put it into a ftrong fire in the fur-
nace, to calcine for twenty-four hours; then beat it to a fine
powder, and fearfe it; put it covered into the furnace, on
earthen tiles, for twelve days, to reverberate ; fo powder, grind,
and keep it for ufe.
Befides a red, it contributes principally to the making a yel-
low and chalcedony.
A red colour fro?n Brass. Put fmall pieces of it into the
arches of the furnace, and let them remain there clofe till they
are well calcined; but in fuch a fire, that they may not melt;
and, when they are well calcined, powder the Brafs, and the
powder will be red, and excellent, in many uies, for colouring
glafs.
b Tte