244 TRANSACTIONS OF THE 
total copper in the fume appearing in the metal that 
results from the reducing fusion. The metal is crude 
metal carrying around 95 per cent copper with 2 per cent 
or so of each of the other elements, iron and sulphur. 
Gold and silver, if present in the copper ore, are volatil- 
ized and reduced to metal with the copper. Copper 
bullion that carries the precious metals should be partially 
refined in the reverberatory furnace where they are 
formed and then sent to the electrolytic plant for com- 
plete refining. 
If the precious metals are not present in amounts 
sufficient to cover the cost of electrolytic refining, the 
crude copper may be completely refined in the reverbera- 
tory furnace by the usual processes of oxidation and 
poling. Such refining treatment of the crude metal gave 
a refined copper metal of above 99 per cent purity. 
