NEW PROCESS FOR THE DETECTION OF COPPER. 343 
ART. LXV.—NEW PROCESS FOR THE DETECTION OF 
COPPER, APPLICABLE TO MEDICO-LEGAL ANALYSIS. 
By M. Verguin, of Lyons. 
This process was suggested by an observation made some 
years since in analysing a mineral of copper. By accident, I 
placed the solution in a platinum capsule, and wishing to 
estimate the copper in the metallic state, placed therein a plate 
of iron. While the iron was not in contact with the platinum, 
no action took place; but the instant it came in contact with 
this latter, the capsule was covered with a very adherent film 
of copper, no precipitation taking place on the iron. The 
adhesion was so strong, that to separate them, nitric acid had 
to be used. I paid but little attention to this fact, and had 
almost forgotten it, when it was called to mind by reading the 
process of Dr. Christison, for the detection of mercury; and I 
sought out a simple process which might be applied to the 
determination of copper in medico-legal analysis. It is this 
which is the subject of the present note. 
Before entering on the description of my process, I will 
rapidly examine the different reagents employed — their degree 
of certainty, and the case in which they will be insufficient. 
These reagents are ammonia, the yellow cyanide of potassium 
and iron, and metallic iron. 
Ammonia acts by dissolving the oxide of copper, and pro- 
ducing a fine blue color; this color is with difficulty perceived, 
if — 1st, the liquid tested contains a salt of which the base is 
precipitated by the ammonia, for then it is disguised by the 
precipitate. 2d, if it is colored by organic matter. It is true 
we may filter, and decolorise by animal charcoal — but when 
but little of the substance is possessed, it is very important 
not to lose any by the number of manipulations. 
The cyanide of potassium and iron detects minute quantities 
of copper ; for this it is necessary that the liquid should be 
pure, and especially that it should not contain a trace of iron, 
