460 TESTING FOR ANTIMONY AND ARSENIC. 
practicable to pass the scales or films alternately out of 
and into the liquor as required. It, however, generally 
happens that in those instances when the greater part of the 
deposit does fall off, still' a sufficient quantity adheres to 
the copper to allow some of it to be dissolved, and its cha- 
racter proved. 
In a case of poisoning which I have had to attend to since 
the commencement of this year, I have submitted copper 
coated by Reinsch’s process (in the examination of various 
portions of viscera), to the action of permanganate of potash, 
&c., as directed by Dr. Odling’s discovery ; and I have also 
submitted other portions of copper, coated at the same time 
from the same viscera, to the several other methods of 
oxidizing and dissolving the coating in potash solution herein 
described; and in each instance obtained the true orange red 
precipitate, proved to be the sulphuret of antimony by dis- 
solving it in strong hydrochloric acid, and thereby producing 
a solution, one part of which when diluted with water gave a 
white precipitate soluble in solution of tartaric acid ; and the 
other part of which when introduced into Marsh’s apparatus, 
along with zinc and diluted acid, yielded deposits of metallic 
antimony, on porcelain and glass, not soluble by the addition 
of chloride of lime or of a mixture of chloride of lime and 
acetie acid. 
I feel that I ought not to conclude this paper without ex- 
pressing thanks to my friend Dr. Taylor, of Guy’s Hospital, 
for the kind intimation he has made to me that, when only a 
small quantity of arsenic is obtained along with a relatively 
large quantity of antimony from viscera into which these 
metals have entered by absorption, a serious question arises 
as to whether the small quantity of arsenic may not have been 
accidentally introduced as an impurity in tartar emetic; saying 
that, within the past few years, he has met with this in so 
many instances that the fact is calculated to create alarm ; and 
that a maker has informed him that arsenical sulphuric acid 
(the acid made from pyrites), is sometimes used in forming 
the sulphate employed in the manufacture of tartar emetic. 
This being so, there are two possible sources whence arsenic 
in tartar emetic may be derived, — one from the antimonial 
ore used, and another from the sulphuric acid. It is quite 
time that such general use of the impure sulphuric acid for 
pharmaceutical purposes should be prohibited ; and I cannot 
but direct attention to the facts mentioned in a paper of mine, 
( On detecting the presence of Arsenic,’ published fifteen 
years ago, in the sixth volume, new series, of the 6 Memoirs of 
the Manchester Philosophical Society,’ and copied into the 
