1amount of silver
in the copper, he alloys it fourfold; for instance, if in
three
quarters of a centumpondium of copper there is less than the following pro
portions, í.e.: half a libra of silver, or half a líbra and a sícílícus, or half a líbra
and a semí-uncía, or half a libra and semí-uncía and a sícílícus, then rich
lead—that is, that from which the silver has not yet been separated—is
added, to the amount of half a centumpondíum or a whole centumpondíum, or
a whole and a half, in such a way that there may be in the copper-lead alloy
some one of the proportions of silver which I have just mentioned, which is
the first alloy. To this “first” alloy is added such a weight of de-silverized
lead or litharge as is required to make out of all of these a single liquation cake
that will contain approximately two centumpondía of lead; but as usually
from one hundred and thirty líbrae of litharge only one hundred líbrae of lead
are made, a greater proportion of litharge than of de-silverized lead is added
as a supplement. Since four cakes of this kind are placed at the same time
into the furnace in which the silver and lead is liquated from copper, there
will be in all the cakes three centumpondía of copper and eight centumpondía
of lead. When the lead has been liquated from the copper, it weighs six
centumpondía, in each centumpondíum of which there is a quarter of a líbra
and almost a sícílícus of silver. Only seven uncíae of the silver remain in the
exhausted liquation cakes and in that copper-lead alloy which we call
“liquation thorns”; they are not called by this name so much because they
have sharp points as because they are base. If in three-quarters of a centum
pondíum of copper there are less than seven uncía and a semí-uncía or a bes
of silver, then so much rich lead must be added as to make in the copper and
lead alloy one of the proportions of silver which I have already mentioned.
This is the “second” alloy. To this is again to be added as great a weight
quarters of a centumpondium of copper there is less than the following pro
portions, í.e.: half a libra of silver, or half a líbra and a sícílícus, or half a líbra
and a semí-uncía, or half a libra and semí-uncía and a sícílícus, then rich
lead—that is, that from which the silver has not yet been separated—is
added, to the amount of half a centumpondíum or a whole centumpondíum, or
a whole and a half, in such a way that there may be in the copper-lead alloy
some one of the proportions of silver which I have just mentioned, which is
the first alloy. To this “first” alloy is added such a weight of de-silverized
lead or litharge as is required to make out of all of these a single liquation cake
that will contain approximately two centumpondía of lead; but as usually
from one hundred and thirty líbrae of litharge only one hundred líbrae of lead
are made, a greater proportion of litharge than of de-silverized lead is added
as a supplement. Since four cakes of this kind are placed at the same time
into the furnace in which the silver and lead is liquated from copper, there
will be in all the cakes three centumpondía of copper and eight centumpondía
of lead. When the lead has been liquated from the copper, it weighs six
centumpondía, in each centumpondíum of which there is a quarter of a líbra
and almost a sícílícus of silver. Only seven uncíae of the silver remain in the
exhausted liquation cakes and in that copper-lead alloy which we call
“liquation thorns”; they are not called by this name so much because they
have sharp points as because they are base. If in three-quarters of a centum
pondíum of copper there are less than seven uncía and a semí-uncía or a bes
of silver, then so much rich lead must be added as to make in the copper and
lead alloy one of the proportions of silver which I have already mentioned.
This is the “second” alloy. To this is again to be added as great a weight
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