542 



BOOK XI. 



of the furnace into the forehearth, is hkewise dipped out with a ladle into 

 oblong copper moulds ; in this way nine or ten cakes are made, which are 

 " dried," together with bad exhausted liquation cakes, and from these 

 " dried " cakes yellow^^ copper is made. 



The cadmia,^ as it is called by us, is made from the " slags " which the 

 master, who makes copper from " dried " cakes, draws off together with other 

 re-melted base " slags " ; for, indeed, if the copper cakes made from such 

 " slags " are broken, the fragments are called cadmia ; from this and yellow 

 copper is made caldanum copper in two ways. For either two parts of cadmia 

 are mixed with one of yellow copper in the blast furnaces, and melted ; or, on 

 the contrary, two parts of yellow copper with one of cadmia, so that the 

 cadmia and yeUow copper may be well mixed ; and the copper which flows down 

 from the furnace into the forehearth is poured out with a ladle into oblong 

 copper moulds heated beforehand. These moulds are sprinkled over with char- 

 coal dust before the caldanum copper is to be poured into them, and the same 

 dust is sprinkled over the copper when it is poured in, lest the cadmia and 

 yellow copper should freeze before they have become well mixed. With a 

 piece of wood the assistant cleanses each cake from the dust, when it is 

 turned out of the mould. Then he throws it into the tub containing hot water, 

 for the caldarium copper is finer if quenched in hot water. But as I have 

 so often made mention of the oblong copper moulds, I must now speak of 

 them a httle ; they are a foot and a palm long, the inside is three palms and a 

 digit wide at the top, and they are rounded at the bottom. 



The concentrates are of two kinds — precious and base.^ The first are 

 obtained from the accretions of the blast furnace, when liquation cakes are 

 made from copper and lead, or from precious liquation thorns, or from the 

 better quaUty " slags," or from the best grade of concentrates, or from the 

 sweepings and bricks of the furnaces in which exhausted liquation cakes are 

 " dried "; all of these things are crushed and washed, as I explained in Book 

 VIII. The base concentrates are made from accretions formed when cakes 

 are cast from base thorns or from the worst quality of slags. The smelter 

 who makes liquation cakes from the precious concentrates, adds to them 

 three wheelbarrowsful of litharge and four barrowsful of hearth-lead and 

 one of ash-coloured copper, from all of which nine or ten liquation cakes 

 are melted out, of which five at a time are placed in the furnace in which 

 silver-lead is liquated from copper ; a centumpondium of the lead which drips 

 from these cakes contains one uncia of silver. The liquation thorns are 



"See Note i6, p. 511, for discussion of yellow and caldarium copper. 



*^his cadmia is given in the Glossary and the German translation as kohelt. A dis- 

 cussion of this substance is given in the note on p. 112 ; and it is sufficient to state here that in 

 Agricola's time the metal cobalt was unknown, and the substances designated cadmia and- 

 cobaltum were arsenical-cobalt-zinc minerals. A metal made from " slag " from refining, 

 together with " base " thorns, would be very impure ; for the latter, according to the paragraph 

 on concentrates a little later on, would contain the furnace accretions, and would thus be 

 undoubtedly zincky. It is just possible that the term kobelt was used by the German smelters 

 at this time in the sense of an epithet — " black devil " (see Note 21, p. 214). 



*'It is somewhat difficult to see exactly the meaning of base (vile) and precious 

 (preciosum) in this connection. While " base " could mean impure, " precious" could hardly 

 mean pure, and while " precious" could mean high value in silver, the reverse does not seem 

 entirely apropos. It is possible that " bad " and " good " would be more appropriate terms. 



