RESEARCH FOR ARSENIC AN!) ANTIMONY. 
547 
the form of chloride. These compounds chiefly concern the 
medical jurist. To one case of poisoning by arsenic acid or 
the sulphide, there will be at least one hundred cases of poi¬ 
soning by arsenious acid. Should it be required to distil 
arsenic acid or its compounds, it will be advisable to convert 
it to arsenious acid by a current of sulphurous acid, or by 
the addition of bisulphite of soda. Sulphide of arsenic may 
be similarly transformed, by being first treated with nitro- 
hydrochloric acid. 
Applications of the process .—including the analyses for arse¬ 
nic in copper already referred to (p. 413), I have applied this 
process during the last year in probably not less than seventy 
instances. In cases in which negative results were obtained 
from the distillate, no arsenic was found by Reinsch’s process 
either in the distillate or in the acid residue in the receiver. 
The process presents this great advantage to the toxicologist, 
it may be safely adopted without interfering with the research 
for other poisons. With the exception of mere traces of 
antimony and bismuth, that pass by distillation, all other 
metals remain in the residue after distillation ; and with re¬ 
spect to these two metals, the greater proportion remains 
behind. Hence, after separating arsenic, the residue may be 
examined for antimony, mercury, copper, lead, and other 
metallic poisons, by the ordinary processes. On the other 
hand, if the presence of any volatile poison, such as alcohol, 
prussic acid, ether, or chloroform, is suspected, a water-bath 
distillation, to separate any of these liquids, may be resorted 
to, before commencing the research for arsenic. A portion 
of the residue may in all cases be reserved for the research 
for organic alkaloids. 
The subjoined experiments were purposely resorted to. in 
order to test the efficacy of the process. 
1. The stomach .—The contents and part of the coats of the 
stomach of a person had been examined for arsenic by 
Reinsch’s process, and no arsenic was found. The remainder 
of the stomach had been exposed for some months, and was 
in a dry state. A solution containing three eighths of a grain 
of arsenic was poured over the surface; in this state it re¬ 
mained exposed five months longer. One third of it was then 
cut up and distilled with two ounces of pure hydrochloric 
acid, in the manner already described (p. 537). The distillate 
was acid, and nearly colourless. It yielded arsenic readily by 
Reinsch’s process, as well as metallic arsenic from arseniu- 
retted hydrogen,—arsenious acid by the use of nitrate of 
silver, and arsenic acid by the use of nitric acid. The dry 
residue in the retort was tested by Reinsch’s process. It 
