86 
ON THE PURIFICATION OF BISMUTH. 
have offered some remedy for a proved defect in a process for which he is sup¬ 
posed to be in part answerable, than to have contented himself with advancing 
the singularly illogical assertion that “ it is precluded by the test.” How can 
a test applied after a process in any way influence the result of that process ? 
All the test is worth is to show whether the process has been successful,—and 
so applied in the present case the answer must be—no! The fact is, the closer 
the Pharmacopoeia treatment of this subject is examined, the more complete is 
the jumble seen to be. Under the heading “ Bismuth ” we are informed that it 
is u a crystalline metal and generally impure.” This is somewhat laconic, but, 
all will admit, not very instructive. What the impurities are likely to be, the 
authorities, possibly for the best of all reasons, forbear to tell us. We are then 
directed to convert this impure “ Bismuthum” into “Bismutlium Purum” by 
a definite process, and certain characters and tests are given to which the result 
is required to answer. Now it unfortunately happens that these characters and 
tests bear no relation whatever to the process : they all apply equally well or 
ill to the unpurified as to the purified metal; whilst, on the other hand, the 
tests that might have been fairly introduced as applicable to a metal that has 
passed through the process are altogether wanting. Surely this may be fairly 
called a jumble, at any rate there is a defect, and for this defect I venture to 
ask the Editor, since he has voluntarily joined the discussion, if he can suggest 
a remedy. Can he give us a good metallurgical process for the separation of 
copper from bismuth ? 
Lest either he or Mr. Wood should feel inclined to repeat the insinuation 
that I exaggerate the frequency and the importance of the copper contamination 
of bismuth, I may perhaps be excused the following bit of personal experience. 
I find, by reference to my books, that since January, 1863, I have purchased 
bismuth on thirty-eight different occasions, in quantities varying from 7 lbs. to 
30 lbs. I have always given the top market price for the best I could get, and 
have purchased of the most respectable refiners of London and Birmingham, and 
I have not found three of these samples free from copper. On the contrary, the 
contamination has been a systematic inconvenience to me, and on several occa¬ 
sions has been so excessive as to render the sample quite unfit for conversion 
into “ Liquor Bismuthi.” With such experience, it was simply impossible 1 
could fail to detect the fundamental error of the Pharmacopoeia process for the 
preparation of its “ Liquor.” Knowing it so well to be a difficult metal to 
obtain pure, and seeing that this process must of necessity include all the solu¬ 
ble impurities of the particular sample, it was, I believed, my simple duty to 
direct professional attention to the probable consequences. 
I believe every candid person who may read this discussion will hold the 
assertions of my advertisement to have been completely justified. In the 
strictest scientific sense, they merely required the admission of possible exceptions 
—whilst, as a commercial statement, which was all they pretended to be, they 
were founded upon large experience, t 
[The above paper was in type for the July number, but in consequence of 
press of matter was omitted.] 
ON THE PURIFICATION OF BISMUTH. 
TO THE EDITORS OF THE PHARMACEUTICAL JOURNAL. 
Sir,—Independent of any knowledge of Mr. Ekin’s experiments, my atten¬ 
tion has been given for some time to the purification of bismuth. Four out of 
six specimens of commercial bismuth I have found containing copper as an 
