NOTE ON COMMERCIAL BISMUTH. 
595 
ment and interests of pharmacy. Compound Decoction of Aloes, if carefully 
made according to the Pharmacopoeia, is an elegant, agreeable, and efficient 
medicine, which keeps well for any reasonable time ; and for this a tincture, 
such as is sometimes substituted for it, is but an imperfect and very inadequate 
representative.—Ei>. Ph. Journ.] 
NOTE ON COMMERCIAL BISMUTH. 
BY CHARLES EKIN, F.C.S. 
Having from time to time made experiments with a view to ascertain the 
impurities present in commercial bismuth, which subject I accepted some months 
ago for the next meeting of the Conference, I wish to record some of the results 
1 have arrived at up to this time, lest the experience of Mr. Wood, which I 
cannot regard as other than exceptional, should cause any misapprehension. 
Mr. Wood tells us, that of several samples he examined, one only contained 
copper, and that but a mere trace, and the inference he leaves us to draw is, 
that bismuth is rarely contaminated with copper: it is true that his samples 
had been purified ( sic ) by the Pharmacopoeia process, but as that process elimi¬ 
nates little, if any, copper, it is evident that Mr. Wood must have been fortu¬ 
nate in procuring such favourable specimens. 
In the course of this last month only, three specimens that I have examined, 
which were purchased as the best commercial metal from leading London Metal¬ 
lurgists, and for which the highest market price was given, all contained copper. 
Each of them gave, in its solution in nitric acid, a distinct blue colour, with 
excess of ammonia, and when this was treated with acetic acid in excess, and 
with ferrocyanide of potassium, a red-brown precipitate of cyanide of iron and 
copper was obtained, varying in degree in each sample but very distinct in all. 
Allowing, however, that this metal is precluded by the Pharmacopoeia test 
from entering into the P.B. liquor, that does not apply in the case of silver, 
which is mentioned in at least one manual of Chemistry,—that of Dr. Odling,— 
as being frequently present in commercial bismuth : that its occasional presence 
at all events is no myth, I will content myself for the present by proving by one 
example, that of a sample of liquor bismuthi P.B., which passed through my 
hands the other day, and which contained silver in very appreciable quantity: 
the liquor was supplied by a very respectable London wholesale firm, and I need 
hardly remark might have been faithfully prepared in accordance witli the in¬ 
structions of the Pharmacopoeia. 
I will leave the consideration of the merits or demerits of the liq. bismuthi P.B. 
to those whom it more immediately concerns, but as Mr. Wood has appealed to 
practical men, to which class I suppose all practising pharmaceutists belong, he 
gives me the right to ask if he really thinks they will approve,— 
1st. Of a plan for purifying the metal which fails to get rid of the silver, 
copper, etc., certainly, and so far as it has yet been proved to the contrary, the 
antimony and arsenic, possibly ; and 2nd. Will they approve of a test which 
fails to detect but one of the several impurities occasionally present? 
We are told in effect that if we start with metal free from the impurities 
which we cannot get rid of by the Pharmacopoeia process, and also, that if we 
adopt other processes than that of the Pharmacopoeia, we ought to obtain a 
pure liquor : no doubt this is so, but it is quite beside the question. 
The question is rather, that, partly because they know no reason why they 
should not do so, and partly on account of the frequent dunnings we have been 
treated to lately by the medical press, to the effect that we must wholly submit 
our reason to the wisdom of the Pharmacopoeia Committee, the majority of 
