DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.19571#0291
THE ARTIST'S ASSISTANT. 277
diamond powder itfelf. Any fuch diamonds which
can be touched by emery,, lead, copper, or other mc-
ls, or be cut therewith, are faife : and this is a
ood teft for knowing a real diamond.
The method of counter-drawing on artificial {tones,
he original camieaus, intalics, and other gems,
vvhich are kept and preferved in the feveral mufeums
of Europe :—Chufe the fineft fort of tripoli which
can poffibly be found ; grind it on marble, into an
impalpable powder, and as fubtile as poffible ; add a
little water to it, fo as to make a fort of pafte with it,
of the confiftence of colours on pallets fof painting ;
when it is in that (late, put it in a little fquare tin
mould, with turned-up edges: prefs well your pafte
down in it, and fmoothen the furface ; as foon as
you fee. it begins to dry, (lamp on it the feal of which
you want to obtain the impreffion, and taking it off
fkilfully from the tripoli pafte, let this dry tho-
roughly ; when you find it is perfectly hard, and
the Itrokcs of the feal are folids, put on the im-
preffion fome powder of cryftal. or any artificial (tone
you pleafe, whether red, green, blue, or any other
colour; then, with a metal pipe, blow on that pow-
der the flame of a candle, or a lamp, till the cryftal
is perfectly melted; when done, lay fomething,
fuch as afmalliron pallet, of nearly the fize of the
feal, on the melted pafte, and prefs it gently to make
it take the better the impreffion, and all the turns
of the den^n, and then let it cool. When you take
the cryftal up you will find it to be a perfect copy of
the original ; you may then fend it to the lapidary to
be cut, and fet for feal or ring as you like. From
thefe very copies you may even get other copies, by
following the fame procefs of operation.
When
diamond powder itfelf. Any fuch diamonds which
can be touched by emery,, lead, copper, or other mc-
ls, or be cut therewith, are faife : and this is a
ood teft for knowing a real diamond.
The method of counter-drawing on artificial {tones,
he original camieaus, intalics, and other gems,
vvhich are kept and preferved in the feveral mufeums
of Europe :—Chufe the fineft fort of tripoli which
can poffibly be found ; grind it on marble, into an
impalpable powder, and as fubtile as poffible ; add a
little water to it, fo as to make a fort of pafte with it,
of the confiftence of colours on pallets fof painting ;
when it is in that (late, put it in a little fquare tin
mould, with turned-up edges: prefs well your pafte
down in it, and fmoothen the furface ; as foon as
you fee. it begins to dry, (lamp on it the feal of which
you want to obtain the impreffion, and taking it off
fkilfully from the tripoli pafte, let this dry tho-
roughly ; when you find it is perfectly hard, and
the Itrokcs of the feal are folids, put on the im-
preffion fome powder of cryftal. or any artificial (tone
you pleafe, whether red, green, blue, or any other
colour; then, with a metal pipe, blow on that pow-
der the flame of a candle, or a lamp, till the cryftal
is perfectly melted; when done, lay fomething,
fuch as afmalliron pallet, of nearly the fize of the
feal, on the melted pafte, and prefs it gently to make
it take the better the impreffion, and all the turns
of the den^n, and then let it cool. When you take
the cryftal up you will find it to be a perfect copy of
the original ; you may then fend it to the lapidary to
be cut, and fet for feal or ring as you like. From
thefe very copies you may even get other copies, by
following the fame procefs of operation.
When