BOOK X. 465 



is nineteen feet distant, and both these walls are thirty-six feet long and 

 fourteen feet high ; a transverse wall extends from the end of the front wall to 

 the end of the rear wall ; then fifteen feet back a second transverse wall 

 is built out from the front wall to the end of the middle wall. In that space 

 which is between those two transverse walls are set up the stamps, by means 

 of which the ores and the necessary ingredients for smelting are broken up. 

 From the further end of the front wall, a third transverse wall leads to the 

 other end of the middle wall, and from the same to the end of the rear waU. 

 The space between the second and third transverse walls, and between the 

 rear and middle long walls, contains the cupellation furnace, in which lead 



arises — the abstrich. This material contains most of the antimony and arsenical impurities. 

 In the third stage the litharge comes over. At the end of this stage the silver brightens — 

 " blicken " — due to insufficient litharge to cover the entire surface. Winkler gives the follow- 

 ing average proportion of the various products from a charge of 100 centners : — 



Ahzug .. 

 Abstrich 

 Herdtplei 

 Impure litharge 

 Litharge 



2 centners, containing 64% lead 



5i >> " 73 /o i> 



2i| „ „ 60% „ 



18 „ „ 85% .. 



66 „ .. 89% „ 



Total . . . . 113 centners 



He estimates the lead loss at from 8% to 15%, and gives the average silver contents of 

 Uicksilber as about 90%. Many analyses of the various products may be found in Percy 

 (Metallurgy of Lead, pp. 198-201), Schnabel and Lewis (Metallurgy, Vol. i, p. 581) ; but as 

 they must vary with every charge, a repetition of them here is of little purpose. 



Historical Note on Cupellation. The cupellation process is of great antiquity, 

 and the separation of silver from lead in this manner very probably antedates the separation of 

 gold and silver. We can be certain that the process has been used continuously for at least 

 2,300 years, and was only supplanted in part by Pattinson's crystallization process in 1833, 

 and further invaded by Parks' zinc method in 1850, and during the last fifteen years further 

 supplanted in some works by electrolytic methods. However, it yet survives as an important 

 process. It seems to us that there is no explanation possible of the recovery of the large 

 amounts of silver possessed from the earliest times, without assuming reduction of that metal 

 with lead, and this necessitates cupellation. If this be the case, then cupellation was practised 

 in 2500 B.C. The subject has been further discussed on p. 389. The first direct evidence of the 

 process, however, is from the remains at Mt. Laurion (note 6, p. 27), where the period of 

 greatest activity was at 500 B.C., and it was probably in use long before that time. Of 

 literary evidences, there are the many metaphorical references to " fining silver " and " sepa- 

 rating dross" in the Bible, such as Job (xxviii, i), Psalms (xii, 6, Lxvi, 10), Proverbs (xvii, 3). 

 The most certain, however, is Jeremiah (vi, 28-30) : " They are all brass [sic'\ and iron ; they 

 " are corrupters. The bellows are burned, the lead is consumed in the fire, the founder 

 " melteth in vain ; for the wicked are not plucked away. Reprobate silver shall men call 

 " them." Jeremiah lived about 600 b.c. His contemporary Ezekiel (xxii, 18) also 

 makes remark : " All they are brass and tin and iron and lead in the midst of the furnace ; 

 " they are even the dross of the silver." Among Greek authors Theognis (6th century B.C.) 

 and Hippocrates (5th century B.C.) are often cited as mentioning the refining of gold with lead, 

 but we do not believe their statements will stand this construction without strain. Aristotle 

 (Problems XXiv, 9) makes the following remark, which has been construed not only as 

 cupellation, but also as the refining of silver in " tests." " What is the reason that boiling 

 " water does not leap out of the vessel .... silver also does this when it is purified. 

 " Hence those whose office it is in the silversmiths' shops to purify silver, derive gain by 

 " appropriation to themselves of the sweepings of silver which leap out of the melting-pot." 



The quotation of Diodorus Siculus from Agatharcides (2nd century B.C.) on gold 

 refining with lead and salt in Egypt we give in note 8, p. 279. The methods quoted by Strabo 

 (63 B.C.-24 A.D.) from Polybius (204-125 B.C.) for treating silver, which appear to involve 

 cupellation, are given in note 8, p. 281. It is not, however, until the beginning of the Christian 

 era that we get definite Hterary information, especially with regard to litharge, in Dioscorides and 

 Pliny. The former describes many substances under the terms scoria, molybdaena, scoria argyros 

 and liihargyros, which are all varieties of litharge. Under the latter term he says (v, 62) : 

 " One kind is produced from a lead sand (concentrates ?), which has been heated in the furnaces 

 " until completely fused ; another (is made) out of silver ; another from lead. The best is 



