4o6 BOOK IX. 



of the alloy there is a bes or three-quarters of silver. In this way every week, 

 if the work is for six days, thirty-six ceniumpondia of cakes are made and 

 three ceniumpondia of aUoy, in all of which there is often almost twenty-four 

 librae of silver. The second smelter separates from the primary cakes the 

 greater part of the silver by absorbing it in lead. To eighteen ceniumpondia 

 of cakes made from crude copper ore, he adds twelve ceniumpondia of hearth- 

 lead and litharge, three ceniumpondia of stones from which lead is smelted, 

 five ceniumpondia of hard cakes rich in silver, and two ceniumpondia of 

 exhausted Uquation cakes*^ ; he adds besides, some of the slags resulting 

 from smelting crude copper, together with a small quantity of concentrates 

 made from accretions, all of which he melts for the space of twelve hours, 

 and makes eighteen ceniumpondia of secondary cakes, and twelve cenium- 

 pondia of copper-lead-silver aUoy ; in each ceniumpondium of the latter 

 there is half a libra of silver. After he has taken off the cakes with a 

 hooked bar, he pours the alloy out into copper or iron moulds ; by this 

 method they make four cakes of alloy, which are carried to the works in 

 which silver is parted from copper. On the following day, the same smelter, 

 taking eighteen ceniumpondia of the secondary cakes, again adds twelve 

 ceniumpondia of hearth-lead and htharge, three ceniumpondia of stones 

 from which lead is smelted, five ceniumpondia of hard cakes rich in silver, 

 together with slags from the smelting of the primary cakes, and with concen- 

 trates washed from the accretions which are usually made at that time. 

 This charge is likewise smelted for the space of twelve hours, and he makes as 

 many as thirteen ceniumpondia of tertiary cakes and eleven ceniumpondia 

 of copper-lead-silver alloy, each ceniumpondium of which contains one- 

 third of a libra and half an uncia of silver. When he has skimmed off the 

 tertiary cakes with a hooked bar, the alloy is poured into copper moulds, and 

 by this method four cakes of aUoy are made, which, like the preceding four 

 cakes of sdloy, are carried to the works in which silver is parted from copper. 

 By tliis method the second smelter makes primary cakes on alternate days 

 and secondary cakes on the intermediate days. The third smelter takes 

 eleven cartloads of the tertiary cakes and adds to them three cartloads of 

 hard cakes poor in silver, together with the slag from smelting the secondary 

 cakes, and the concentrates from the accretions which are usually made 

 at that time. From this charge when smelted, he makes twenty cenium- 

 pondia of quaternary cakes, which are called " hard cakes," and also 

 fifteen ceniumpondia of those " hard cakes rich in silver," each cenium- 

 pondium of which contains a third of a libra of silver. These latter cakes the 

 second smelter, as I said before, adds to the primary and secondary cakes 

 when he re-melts them. In the same way, from eleven cartloads of qua- 

 ternary cakes thrice roasted, he makes the " final " cakes, of which one 

 centumpondinm contains only half an uncia of silver. In this operation he 

 also makes fifteen ceniumpondia of " hard cakes poor in silver," in each 

 ceniumpondium of which is a sixth of a libra of silver. These hard cakes the 



•^Exhausted liquation cakes {panes aerei fathiscenies). This is the copper sponge resulting 

 from the first liquation of lead, and still contains a considerable amount of lead. The liquation 

 process is discussed in great detail in Book XI. 



