BOOK X. 483 



The cupellation furnace in Poland and Hungary is likewise vaulted at the 

 top, and is almost similar to an oven, but in the lower part the bed is solid, 

 and there is no opening for the vapours, while on one side of the crucible is a 

 wall, between which and the bed of the crucible is a passage in place cf the 

 opening for vapours ; this passage is covered by iron bars or rods extending 

 from the wall to the crucible, and placed a distance of two digits from each 

 other. In the crucible, when it is prepared, they first scatter straw, and then 

 they lay in it cakes of silver-lead alloy, and on the iron bars they lay wood, 

 which when kindled heats the crucible. They melt cakes to the weight of some- 

 times eighty centumpondia and sometimes a hundred centumpondia^^ . They 

 stimulate a mild fire by means of a blast from the bellows, and throw on to the 

 bars as much wood as is required to make a flame which will reach into the 

 crucible, and separate the lead from the silver. The Utharge is drawn out 

 on the other side through an aperture that is just wide enough for the master 

 to creep through into the crucible. The Moravians and Cami, who very 

 rarely make more than a hes or five-sixths of a libra of silver, separate 

 the lead from it, neither in a furnace resembling an oven, nor in the crucible 

 covered by a dome, but on a crucible which is without a cover and exposed to 

 the wind ; on this crucible they lay cakes of silver-lead alloy, and over them 

 they place dry wood, and over these again thick green wood. The wood 

 having been kindled, they stimulate the fire by means of a bellows. 



I have explained the method of separating lead from gold or silver. Now 

 I will speak of the method of refining silver, for I have already explained 

 the process for refining gold. Silver is refined in a refining furnace, 

 over whose hearth is an arched chamber built of bricks ; this chamber 

 in the front part is three feet high. The hearth itself is five feet long 

 and four wide. The walls are unbroken along the sides and back, but 

 in front one chamber is placed over the other, and above these and the 

 wall is the upright chimney. The hearth has a round pit, a cubit wide and two 

 palms deep, into which are thrown sifted ashes, and in this is placed a prepared 

 earthenware " test," in such a manner that it is surrounded on all sides 

 by ashes to a height equal to its own. The earthenware test is filled 

 with a powder consisting of equal portions of bones ground to powder, and of 

 ashes taken from the crucible in which lead is separated from gold or silver ; 

 others mix crushed brick with the ashes, for by this method the powder 

 attracts no silver to itself. When the powder has been made up and 

 moistened with water, a little is thrown into the earthenware test and tamped 

 with a wooden pestle. This pestle is round, a foot long, and a palm and a 

 digit wide, out of which extend six teeth, each a digit thick, and a digit and a 

 third long and wide, and almost a digit apart ; these six teeth form a circle, 

 emd in the centre of them is the seventh tooth, which is round and of the 

 same length as the others, but a digit and a half thick ; this pestle tapers a 

 httle from the bottom up, that the upper part of the handle may be round 

 and three digits thick. Some use a round pestle without teeth. Then a 



'^If Agricola means the German centner, this charge would be from about 4.6 to 5.7 short 

 tons. If he is using Roman weights, it would be from about 3 to '^.'j short tons. 



