540 BOOK XL 



duced when the exhausted Uquation cakes are " dried." By both methods 

 one single hquation 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 Uquation 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 hquation 

 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 usuaUy weigh quite a centumpondium. In aU the liquation 

 cakes together there is usuaUy 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 hquation thorns there is almost an uncia of silver, and 

 in the two centumpondia and a quarter of exhausted hquation 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 hquation cakes made of 

 copper and lead when silver-lead is hquated 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 Uttle further on. 



Those in the Carpathian Mountains who make hquation 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 hquated from the copper. These, together 

 with those made of cakes of re-melted thorns, or made with re-melted htharge, 

 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 

 hkewise those produced from " drying " the exhausted hquation 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 wiU return to ours. 



The ash-coloured copper ^^ 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 re- 

 melted 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 



^*The "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. 



