232 
RESEARCH FOR ARSENIC AND ANTIMONY. 
the presence of arsenic in refined copper was entirely un¬ 
known as a chemical fact, or wholly ignored as an obstacle to 
the safe use of Reinsch’s process for the detection of arsenic. 
Orfila, it is true, recommends, as a precaution, that the cop¬ 
per used should be heated in a tube, to ascertain whether it 
evolves arsenious acid, before boiling it with hydrochloric 
acid and the suspected substance. With this supposed pre¬ 
caution, which, it need hardly be said, is not, chemically 
speaking, sufficient to distinguish arsenical from non-arseni- 
cal copper, he relied upon the production of the metallic 
deposit as a perfectly safe and certain indication of the 
presence of arsenic in the substance examined.* Flandin, 
who was opposed to the use of any process for detecting 
arsenic excepting his own, objected to Reinsch’s method, not 
on the ground of arsenic being possibly conveyed to the 
liquid by copper, but because it was less delicate than the 
process of carbonization by sulphuric acid.f Galtier, in his 
c Traite de Toxicologic, 5 1855, i, p. 343, describes Reinsch’s 
process, and merely requires that the copper should be clean 
and the diluted acid pure. Devergie speaks of it as a process 
but little employed, and simply points out that clean copper is 
required for the deposition of the arsenic.J 
In fact, whether among English or French and German 
writers on chemistry and toxicology, there is not one who has 
ever pointed out, or even suspected, that this process would 
lead to error by reason of the universal presence of arsenic 
in copper, commercial or refined, which is accessible to the 
chemist.§ All have hitherto relied upon the cleanness of the 
affect the results, as the test is ordinarily used ; but it is clear, if metallic 
copper is condemned because it contains traces of arsenic, no salt of copper 
can escape condemnation for a similar reason. It is the presence of a large 
quantity of arsenic in the commercial sulphate which is the cause of the 
occasional deposition of arsenic with copper by electrolysis. 
* ‘Traitede Toxicologic, 5 fifth edition, 1852, tome i, p. 521. 
f ‘ Traite des Poisons,’ i, 625, 1846. 
% ‘Medecine Legale,’ Paris, 1852, tomeiii, p. 460. 
§ That wisdom which is almost invariably manifested after an event was 
shown soon after the trial of Smethurst, in comments upon the chemical 
evidence. It was suggested by one chemist that the copper -gcntze which 
Dr. Odling and I had been in the habit of using for some years in the 
lectures on Chemistry and the demonstrations on Practical chemistry at 
Guy’s Hospital was of an arsenical nature, while coppery^// or wire either 
was or might be easily obtained free from arsenic; that every chemist knew 
there was arsenic in copper, and that no one but ourselves had employed 
Reinsch’s process without first dissolving a portion of the copper in an acid 
or in chlorine, and testing the salt, thus produced for arsenic. It. was forced 
upon the attention of the Court that one of the chemists for the defence had 
always taken especial care to use electrotype copper, as if this fact was a 
guarantee against its containing any arsenic. (See p. 30.) In short, what- 
