RESEARCH FOR ARSENIC AN1) ANTIMONY. 
231 
‘Elements of Chemistry/ 1856, part ii, p. 980, does not 
speak of the contamination of refined copper by arsenic; 
but in reference to commercial copper, he states that it is 
very nearly pure ; it contains minute quantities of arsenic, 
iron, and lead. It is worthy of notice, that among the above- 
mentioned chemical authorities there are three (Mr. Brande, 
Dr. Miller, and Messrs. Abel and Bloxam) who especially de¬ 
scribe Reinsch's process for detecting arsenic, and they con¬ 
cur in stating that the only test required for ascertaining the 
purity of the materials used, is first to boil the copper in 
diluted hydrochloric acid, in order to ascertain their purity 
before employing them as tests (Brande, p. 933; Miller, p. 
967 ; Abel and Bloxam, p. 571). Messrs. Abel and Bloxam 
recommend the use of ordinary copper-wire cleaned with 
concentrated nitric acid and washed. 1 might add to these 
authorities the names of Orfila, Devergie, Schneider, Che¬ 
vallier,* and other writers on toxicology, to prove either that 
* Among all the works in the English and French languages on the 
adulterations and impurities of substances employed in chemistry, medicine, 
and the arts, there is, perhaps, none which can compete in comprehensive¬ 
ness with the ‘ Dictionnaire des Alterations et Falsifications des Substances 
Alimentaires, Medicamenteuses, et Commerciales/ by ML Chevallier, of which 
the third edition was published in 1857- It consists of two volumes, com¬ 
prising nearly 1400 pages. M. Chevallier is much employed in Paris in 
medico-legal analyses. On referring to this work (tome i, pp. 19 and 51; 
tome ii, p. 672). it will be found that the author is especially careful to 
describe arsenic as an impurity in sulphuric and hydrochloric acids and in 
zinc; to explain the means for its detection and separation, and to caution 
analysts in reference to its presence in these substances; but he does not 
even refer to copper, although he has himself published papers on its 
application and use, in reference to Reinsch’s process. The only inference 
to be drawn from this omission is, that he either was not aware of the 
existence of arsenic in copper, or that its presence exerted so little influence 
on the uses of this metal as to render it unnecessary to notice it as an 
impurity. 
The fact that all the commercial and nearly all the medicinal sulphate of 
copper contains arsenic, is also unnoticed by this writer. At p. 467, tome 
ii, lie merely refers to the presence of sulphates of iron and zinc in sulphate 
of copper. There is so much arsenic in the ordinary sulphate, that ten grains 
of the crystals will commonly yield clear evidence of its presence. Other 
writers of repute on Materia Mledica have, like M. Chevallier, overlooked 
this fact. Thus, Pereira (‘ Materia Mledica/ i, p. S72) describes traces of 
sulphate of iron as the only impurity. The presence of this arsenical 
impurity may have an important bearing on evidence. If a man has taken 
large doses of sulphate of copper as an emetic and dies, arsenic may be 
found in the contents of his stomach, although none may have been adminis¬ 
tered. Chemists relying upon thousandths’ of grains may thus be deceived, 
and mislead a court of law by their evidence. It is not a little remarkable 
that those who have condemned the use of copper containing arsenic, have 
either ignorantly or knowingly employed the sulphate of copper as a test 
for arsenic, without having previously tested this test for the poison itself. 
It is true that the quantity of arsenic present is small, and is not likely to 
