4
staters. Having melted the copper, spread upon it the earth of Chios
and the lamellose alum crushed together, stir in such a way as to mix
them; and having melted this asem, pour. Having mixed that which has
just been melted with some (wood of) juniper, burn it; before setting
aside after having heated it, extinguish the product in lamellose alum
and salt taken in equal parts, with some slimy water slightly thick;
and if you wish to finish the work immerse again in the
above-mentioned; heat so (the metal) becomes white. Take care to
employ refined copper beforehand, having heated it at the beginning
and submitted it to the action of the bellows, until this has rejected
its scale and become pure; and then use it as has just been stated.
20. Another (Formula).
Take
a Ptolemaic Stater; for they contain copper in their composition and
immerse it; now, the composition of the liquid for the immersion is
this: lamellose alum, common salt, in vinegar for immersing; (make it
of) slimy thickness. After having immersed and at the moment when the
melted metal has been cleaned with this composition, heat, then
immerse, then take out, then heat.
20. (An additional part without a title).
Here
is the composition of the liquid for immersing: lamellose alum, common
salt, in the vinegar for immersing; (make of) slimy thickness; having
immersed in this mixture, heat, then immerse, then take out, then heat;
when you have immersed four times or more, by previously healing each
time, the (metal) will become superior to blackened asem. The more
numerous the treatments, heatings, and immersions are the more it will
improve.
21. Treatment of Hard Asem.
How
it is expedient to proceed to change black and hard asem into a white
and soft (metal). Taking some leaves of the castor-oil plant infuse
them a day in water; then soak (it) in the water before melting and
melt twice and sprinkle with aphronitron. And throw alum on the
casting; put into use. It possesses quality for it is beautiful.
The
word "aphronitron" was applied to a variety of saline efflorescences
especially from dry or arid regions. Most probably it was a natural
alkali which was essentially sodium carbonate.
22. Another (Formula).
A
remedy for all tarnished asem. Taking straw, barley, and wild rue,
infuse in vinegar, pour on it some salt and coals; throw it all in the
furnace, blow for a long while and let cool.
23. Whitening of Copper.
For
whitening copper, in order to mix it with equal parts of asem, so that
no one can recognize it. Taking some Cyprian copper, melt it, throwing
on it 1 mina of decomposed sandarach, 2 drachmas of sandarach of the
color of iron, and 5 drachmas of lamellose alum and melt (again). In
the second melting, there is thrown on 4 drachmas, or less, of wax of
Pontus: it is heated and then poured.
Sandarach
was the term used to denote the native arsenic sulfide that is today
known as realgar by the mineralogists. "Decomposed sandarach" possibly
referred to that subjected to a roasting process and would in reality
be the oxide.
24. Hardening of Tin.
For
hardening tin, spread separately (on its surface) lamellose alum and
copperas; if, moreover, you have purified the tin as is necessary and
have employed the materials
