12 
Copper i, 
way can only give an approximation to accuracy in the 
result, except in the treatment of the pure native oxyds 
or carhonats, which are indeed among the most valuable 
ores, but are those which the seldomest come under the 
notice of the practical metallurgist. 
The analysis of copper ores in the moist way is per- 
formed in a tolerably uniform manner, the ore being first 
treated with an acid which dissolves all the metallic part* 
leaving the sulphur and silex ; after which the different 
metals are separately precipitated from the solution, either 
in the metallic state, or in certain known forms of combi- 
nation, from which the metallic portion can be accurately 
inferred. 
The particular steps of many of these analysis will be 
presently given ; the general mode of separating copper 
from the metals with which it is alloyed is as follows ; 
from silver , by adding to the nitrous solution of the mixed 
metals muriat of soda, which separates the silver, as luna 
cornea, and leaves the copper : from lead , by adding to 
the solution sulphat of soda, which precipitates an insoliu 
ble sulphat of lead, and leaves the copper ‘.—from anti- 
mony, by digesting the mixed oxyds of copper and anti- 
mony with nitric acid, which dissolves the copper and 
leaves the antimony .—from iron , by supersaturating the 
mixed solution with ammonia, which redissolves the cop- 
per and leaves the oxyd of iron : or else by immersing a 
piece of polished iron in the solution, which will separate 
the copper and leave the iron in solution, (a precau- 
tion to be observed here, however, will be presently men- 
tioned) \—from tin, by immersing a piece of metallic tin 
in the solution, which will precipitate the copper only 
from arsenic, by dissolving in nitrous acid and adding 
acetite or nitrat of lead which will separate the arsenic in 
the form of an insoluble ar§eniat of lead, and leave the 
copper. If an excess of lead remain, add sulphat of soda, 
as above mentioned i—from Nickel iu the followiqg way $ 
