duced when the exhausted liquation cakes are " dried." By both methods
one single liquation cake is made from three centumpondia. In this manner
the smelter makes every day fifteen liquation cakes, more or less; he takes
great care that the metallic substances, from which the first liquation cake is
made, flow down properly and in due order into the fore-hearth, before the
material of which the subsequent cake is to be made. Five of these liquation
cakes are put simultaneously into the furnace in which silver-lead is liquated
from copper, they weigh almost fourteen centumpondia, and the "slags"
made therefrom usually weigh quite a centumpondium. In all the liquation
cakes together there is usually one libra and nearly two unciae of silver, and
in the silver-lead which drips from those cakes, and weighs seven and a half
centumpondia, there is in each an uncia and a half of silver. In each of the
three centumpondia of liquation thorns there is almost an uncia of silver, and
in the two centumpondia and a quarter of exhausted liquation cakes there
is altogether one and a half unciae ; yet this varies greatly for each variety of
thorns, for in the thorns produced from primary liquation cakes made of
copper and lead when silver-lead is liquated from the copper, and those
produced in " drying " the exhausted liquation cakes, there are almost two
unciae of silver; in the others not quite an uncia. There are other thorns
besides, of which I will speak a little further on.
Those in the Carpathian Mountains who make liquation cakes from the
copper " bottoms " which remain after the upper part of the copper is
divided from the lower, in the furnace similar to an oven, produce thorns when
the poor or mediocre silver-lead is liquated from the copper. These, together
with those made of cakes of re-melted thorns, or made with re-melted litharge,
are placed in a heap by themselves; but those that are made from cakes
melted from hearth-lead are placed in a heap separate from the first, and
likewise those produced from " drying " the exhausted liquation cakes are
placed separately ; from these thorns liquation cakes are made. From the
first heap they take the fourth part of a centumpondium, from the second
the same amount, from the third a centumpondium,—to which thorns are
added one and a half centumpondia of litharge and half a centumpondium of
hearth-lead, and from these, melted in the blast furnace, a liquation cake is
made; each workman makes twenty such cakes every day. But of theirs
enough has been said for the present; I will return to ours.
The ash-coloured copper 29 which is chipped off, as I have stated, from
the " dried " cakes, used some years ago to be mixed with the thorns produced
from liquation of the copper-lead alloy, and contained in themselves, equally
with the first, two unciae of silver ; but now it is mixed with the concentrates
washed from the accretions and the other material. The inhabitants of the
Carpathian Mountains melt this kind of copper in furnaces in which are remelted the " slags " which flow out when the copper is refined; but as this
soon melts and flows down out of the furnace, two workmen are required for
a9The " ash-coloured copper " is a cuprous oxide, containing some 3% lead oxide;
and if Agricola means they contained two unciae of silver to the centumpondium, then they
ran about 48 ozs. per ton, and would contain much more silver than the mass.
