168 Miscellaneous Intelligence. 
liquor arsenicalis on being boiled for a few minutes with ivory black 
was rendered so colourless that any of the tests for arsenic could 
be readily applied. The experiment was repeated, substituting for 
the colouring liquor, port wine, gravy-soup, and a strong infusion 
of onions, and in all these cases a solution was obtained sufh- 
ciently colourless for the application of the most delicate tests. 
This agent is not liable to any mistake from the presence of phos- 
phates, for water or wine boiled in it alone separated nothing ex- 
cept, in one or two cases, a small portion of a muriate; to avoid 
the interference of this substance, the ivory black may be washed 
-with boiling distilled water until the washings do not affect nitrate 
of silver; but good ivory black does not require this treatment. 
With regard also to the application of sulphate of copper as a 
test of arsenic, Mr. Phillips recommends a precaution which has 
not heretofore been thought of. Sulphate of copper yields a green 
precipitate when added to potash, white arsenic being present; but 
if the sulphate contains any peroxide of iron,.it may yield a green 
precipitate with the alkali, the arsenic not being present. Mr. P. has 
remarked that the arsenic may be added after as well as before the 
precipitate is formed, for the blue precipitate occasioned by the 
potash in pure sulphate of copper becomes green when the white 
arsenic is added. Add solution of potash first, therefore, to the 
sulphate of copper, and obtain the fine blue precipitate; to a part 
of this add the suspected solution, and if arsenious acid be pre- 
sent it will convert the blue precipitate into a green one. — Ann. Phil. 
N. S. vii. 30. 
In reference to the reduction of arsenic to the metallic state, as 
a test of its presence, Dr. Trail thinks the general opinion of the 
large quantity required is unfounded, and easily succeeds in ob- 
taining this evidence from 54; of a grain of white arsenic. The 
tube is to be 24 inches long, 0. 4 inch. wide, and closed at one 
end. The substance thought to be arsenic should be mixed with 
thrice its weight of black flux, or sub-carb. soda mixed with char- 
coal powder, introduced into the tube, and a little charcoal powder 
put over it; the upper part of the tube must be cleaned, and the 
-mouth closed by a piece of paper. The flame ofa spirit-lamp will 
in about two minutes produce a shining metallic crust on the upper 
side of the tube; when cold shake out the loose materials, scrape 
off the metallic crust, which will afford sufficient for six different 
portions, each of which when projected on a dull red-hot poker will 
give a white smoke and alliaceous odour. A clean knife held in 
the smoke will always condense a portion of white powder.—Ann, 
Phil. vii. 132. 
23. On the Detection of Acetate Morphia in cases of Poisoning, 
by M. J. L. Lassaigne.—The following are the processes recom- 
mended. If the acetate of morphia be suspected in a liquid, it is 
