290 
RESEARCH FOR ARSENIC AND ANTIMONY. 
could easily be procured. In order to test the accuracy of 
this statement, I have, since the trial, made an examination 
of seven samples of electrotype copper, three of which were 
prepared by myself, one was prepared by a respectable London 
firm, and another sample was procured from ElkingtorPs 
electro-plating factory at Birmingham. Two others were 
given to me by friends. In five of these no arsenic was 
detected ; in the sixth a small quantity w’as found; and in 
that w r hich in richness of colour and flexibility surpassed all 
the other samples, namely, Elkington’s copper, known under 
the name of “ copper-edgings,” arsenic was detected in well- 
marked proportion. The purity of electrotype copper cannot ? 
therefore, be taken for granted; every sample should be 
tested before it can be pronounced to be free from arsenic. 
The purity or impurity of the deposited copper no doubt 
depends on the purity of the sulphate employed, and the 
rapidity of deposit. 1 Mr. Dugald Campbell has furnished 
me w ith the results of his experience in the subjoinedl etter. 
“ Arsenic in Copper . 
“In compliance wdth your request, I now WTite to you the 
results of my examination of twenty samples of copper, which 
1 The above-mentioned facts show how extensively arsenic is diffused. 
Our copper coinage contains a large proportion. I have detected arsenic in 
the copper coinage of all our sovereigns, from the present time to the 
reign of George II. I found it, but in smaller proportion, in a coin of the 
reign of Augustus Csesar; and in a portion of brass from a sepulchral 
inscription of the reign of Henry V (1416). All our copper culinary uten¬ 
sils contain it; and when these are corroded or destroyed by acids, salts, 
or fat, arsenic is set free. The arsenic is deposited with the insoluble 
copper salt, and may be detected in it. Thus, in the insoluble oxychloride 
of copper, deposited as a result of the action of common salt on copper under 
exposure to air, I have found arsenic, but not in the liquid. Salt fish, 
cooked and allowed to cool in a copper vessel, may thus become impregnated 
with arsenic. Brass contains a large proportion of arsenic, derived from 
the zinc as well as the copper. As brass nails and plates are frequently and 
profusely used for coffins, insoluble cupreous salts containing arsenic may 
be formed during the decay of the body, and become intermixed with the 
remains. This is a point which requires looking to when chemists rely upon 
thousandths of grains, and they are engaged in analysing the remains of 
the dead after some years’ interment. In an exhumation of a body after 
nearly two years’ burial, at which I was present, I noticed on the front, of 
the dress covering the body a large brass button, which had become 
incrusted with a blue deposit of hydrated oxide and carbonate of copper, 
heightened in colour by the ammonia of decomposition. I have no doubt 
that had this been tested it would have yielded arsenic. Nickel silver, con¬ 
taining half its weight of copper and about one third of its weight of zinc, 
also contains arsenic. The native subchloride of copper, obtained from the 
Atacama desert in Peru, did not yield any trace of arsenic. 
