T. S. Hunt on the Chemistry of Copper. 155 
converted into ferric oxyd, with precipitation of metallic cop- 
per. The first stage in the action of ferrous chlorid on cuprous 
oxyd may be represented as similar to that of magnesic chlorid: 
Cu,O+ FeCl= Cu,Cl+ FeO. In the second stage Cu,Cl+ 
38FeO=Cu,+FeCl+Fe,0,. It follows from this that one-third 
of the cuprous chlorid formed in the first stage is reduced to 
the metallic state, and the final result may be represented as 
follows: 8Cu,0+2FeCl=2Cu, Cl4+2Cu+Fe,0,. 
A similar result is obtained if ferrous chlorid is added to an 
cu 
ch 
Cu,Cl+FeCl+Fe,O,. The further action of ferrous oxyd 
will, as we have seen, reduce the cuprous chlorid to the metallic 
state: in fact, 2CuCl+6FeO=2Cu+2FeCl+2Fe,0,. - 
ae precipitated hydrated ferrous oxyd or ferrous carbonate 
a 
prous 
ores which is dissolved, leaving behind only hydrated Lge 
oxyd. Wh i c 
ammonium and excess of ammonia is added to a solution 
th y 
_ §7. It was long since shown by Levol that hydrated ferrous 
_ oxyd will reduce cupric to cuprous oxyd, and this, as we have 
ready seen, can separate from its combinations ferrous oxyd, 
