6 
Copper . 
gested with moderately diluted nitric acid, as long as any- 
thing continues to be taken up by this menstruum. Ta 
the nitric solution is then to be added rnuriat of soda, 
which will throw down the silver in the state of luna cor- 
nea ; this being separated, the lead is to be precipitated in 
the form of sulphat, by sulphat of soda ; the solution is 
now to be supersaturated with ammonia, which will dis- 
solve the copper, and leave behind the ox yd of iron, with 
probably a little aiumine and silex. The copper is to be 
procured from the ammoniacal solution, in the manner 
directed in the preceding paragraph ; and the ox yd of 
iron may be separated from the admixed earths, by caustic 
potash. That portion of ore, insoluble in nitric acid, is 
to be digested in muriatic acid, which will take up every 
thing except the sulphur, silex, and probably a little luna 
cornea. Of this insoluble residue, the sulphur is to be 
burnt off by gentle ignition, and the remainder is to be 
fused with twice its weight of pearl ash, by which the sil- 
ver in the luna cornea will be reduced to the metallic state. 
The muriatic solution being concentrated by evaporation, 
and then poured into a considerable quantity of water, 
will deposit the antimony in the form of a white oxyd. 
The simple oxyds of copper , are best analyzed by di- 
gestion in nitric acid, and then supersaturating the solu- 
tion with ammonia, by which any casual admixture of 
iron will be separated. 
The carbonats of copper are to be thus treated. One 
portion is to be gently calcined in a covered crucible, 
and the loss of weight sustained, indicates the united a- 
jnonnt of the water and carbonic acid. A second portion 
is to be thrown into a known quantity of dilute sulphuric 
acid, and the loss of weight, by the effervescence which 
ensues, shows the amount of carbonic acid. The sulphat 
of copper thus obtained, may be subsequently decom- 
posed, either by a stick of zinc, or by liquid ammonia. 
The arseniats of copper are most conveniently ana- 
