-
.
previously
named, in such a way that they did not escape by flowing away during
the heating, you will have Egyptian asemfor the manufacture of objects
(of jewelry).
25. Gold Polish.
For
treating gold, otherwise called, purifying gold and rendering it
brilliant: Misy, 4 parts; alum, 4 parts; salt, 4 parts. Pulverize with
water. And having coated the gold (with it), place it in an earthenware
vessel deposited in a furnace and luted with clay, (and heat) until the
above-named substances have become molten, then withdraw it and scour
carefully.
26. Purification of Silver.
How
silver is purified and made brilliant. Take a part of silver and an
equal weight of lead; place tn a furnace, and keep up the melting until
the lead has just been consumed; repeat the operation several times
until it becomes brilliant.
27. Coloring in Silver.
For
silvering objects of copper: tin in sticks, 2 drachmas; mercury, 2
drachmas; earth of Chios, 2 drachmas. Melt the tin, throw on ihe
crushed earth, then the mercury, and stir with an iron and fashion into
globules.
28. Manufacture of Copper Similar to Gold.
Crush
some cumin; pour on it some water, dilute, and let it remain in contact
during three days. On the fourth day shake, and if you wish to use it
as a coating mix chrysocolla with it; and the gold will appear.
The
word chrysocolla referred to salts of copper and to a gold alloy used
for soldering gold. In the above recipe, which is evidently a varnish,
the latter was probably used in a pulverized form.
29. Manufacture of Fusible Asem.
Copper
of Cyprus, 1 part; tin, 1 part; stone of Magnesia, 1 part; raw stone of
Paros powdered finely. One melts the copper first, then the tin, and
then the stone of Magnesia; then next, one throws the pulverized stone
of Paros upon this; the stirring is done with an iron and the operation
is performed in a crucible.
30. Manufacture of Asem.
Tin,
a measure; copper of Galacia, a half measure. Melt at first the copper,
then the tin, stir with an iron, and throw on it dry pitch, until it is
saturated; immediately pour, remelt, employing lamellose alum in the
same manner as the pitch, and then pour (again). If you wish to melt
the tin first, then the copper in filings after, follow the same
proportions in ihe same manner.
31. Preparation of Chrysocolla.
Solder
for gold is prepared thus: copper of Cyprus, 4 parts; asem, 2 parts;
gold, 1 part. The copper is first melted, then the asem and finally the
gold.
32. To Recognize the Purity of Tin.
After having melted, place some papyrus below it and pour; if the papyrus burns, the tin contains some lead.
33. Manufacture of Solder for Working Gold.
How
one goes about making the solder for works of gold: Gold, 2 parts;
Copper, 1 part; melt (and) divide up. When you desire a brilliant color
melt with a little silver.
