MEDICO-LEGAL CONTRIBUTIONS ON ARSENIC. 
443 
arsenic, be converted into the yellow sulphide of arsenic, 
and if antimony, into the orange or black sulphide of anti¬ 
mony. 
d. If dry chlorh 3 'dric acid gas be passed into the tube 
(treated as above), when cold the deposit, if of sulphide of 
arsenic, remains unchanged, if of sulphide of antimony it is 
converted into chloride of antimony, and is volatilized. (The 
spot, if unchanged, may be dissolved in ammonia, and further 
experimented with.) 
2. Treatment of the spots on porcelain. — a. Arsenic spots 
when moistened with a solution of hypochlorite of soda im¬ 
mediately disappear. ‘ Antimony spots are not affected, at 
least, not until after a long time. 
h. An arsenic spot treated with a drop of yellow sulphide 
of ammonium dissolves slowly and imperfectly ; an anti¬ 
mony spot rapidly disappears. If, after this treatment, they 
are allowed to dry, the antimony spot assumes a rich orange 
tint, the arsenic spot a light lemon colour on the borders, 
with a larger or smaller mass of undissolved metal in the 
centre. 
It may be remarked, that not unfrequently solutions con¬ 
taining organic matter are introduced into Marsh’s apparatus. 
This is extremely improper, for organic matter alone occa¬ 
sionally produces mirrors similar to those obtained by arsenic 
and antimony, and if these metals are present the indica¬ 
tions are neither so clear nor so satisfactory as when pure 
solutions are used. 
4. Reinsch^s test. —Hugo Helnsch published in 1843 {Aim. 
d^Hygeine, 1843, vol. i, ]). 439) a simple method of detecting 
arsenic. It may be stated as follows :—The suspected mass, 
if not liquid, is to be finely divided, placed in a porcelain 
dish with water, and chlorhydric acid added until distinctly 
acid. The mixture is then to be boiled until it becomes, 
as far as possible, homogeneous. It is then to be strained 
or filtered, and boiled again with strips of bright copper foil 
or gauze. Arsenic, if present, is deposited upon the copper, 
which becomes blackened. The metallic slips are then care¬ 
fully washed, dried, and heated in a glass tube closed at one 
end, when arsenious acid sublimes, which may be recognised 
by its solubility in water and by the liquid tests noted here¬ 
after. (The liquid prepared from the suspected organic 
matter, in the manner previously mentioned, is admirably 
fitted for this purpose.) Lippart has shown [Journ. fiir 
' Prah. Chem.i Ixxxi, p. 16) that the deposit is not pure arsenic, 
as was generally supposed, but a combination of arsenic and 
