85 
ORIGINAL AND EXTRACTED ARTICLES. 
ON MR. WOOD’S PAPER UPON LIQUOR BISMUTHI ET 
AMMONLE CITRATIS. 
BY G. F. SCHACHT. 
In my last communication, published in the April number of this Journal, 
I declared my intention to refer more particularly to the efficiency of the Phar- 
macopoeia process for the purification of bismuth from arsenic, as soon as 1 had 
found leisure to repeat and extend some of my old experiments. 
I have now completely satisfied myself upon the point. I find the process in 
this respect to be certainly more useful than for the removal of copper, but, to 
say the best of it, to be somewhat limited in its value. Amongst other con¬ 
ditions of uncertainty, its success depends much upon the quantities operated 
upon. When these are small, as for instance, 1000 grs. of the metal, the 
process, with much care as to temperature, and efficiency of stirring, succeeds 
well; the loss of bismuth is large, but what remains is free from arsenic. 
When the exact quantities of the Pharmacopoeia are employed, viz. 10 oz. of 
the metal, the arsenic is not entirely removed, and when as much as 10 lbs. are 
operated upon, the proportion of arsenic retained in the metal is considerable. 
I may as well state the plan I adopted for the detection of the arsenic was, 
to fuse 100 grs. of the sample with 200 grs. of pure zinc, and to pass the hydro¬ 
gen generated from this mixture through a narrow German glass tube, heated 
to redness for half an hour. But I also found the combustion of the gas on a 
■cold white plate sufficiently delicate for the purpose. 
So much in answer to Mr. Wood’s original paper. Since that was published, 
however, the Editor of the Pharmaceutical Journal has entered the controversy, 
Mr. Wood has published a second paper, and two notes on the subject have 
Been presented by Mr. Ekin, of Bath. 
Mr. Ekin’s first communication, though short, is very important. He finds 
experimentally, and as a matter of fact, what my advertisement indicated as 
the probable result of an imperfect process. He examined several samples of 
the Pharmacopoeia “ Liquor Bismuthi et Ammonia? Citratis,” procured from 
good wholesale houses, and found them “ all contaminated with arsenic.''' 1 His 
paper of June refers to the prevailing impurities of the metal bismuth, and to 
the inefficiency of the Pharmacopoeia process for their removal. Mr. Ekin is a 
perfectly independent witness, and his testimony is a complete endorsement of 
my statements. 
Mr. Wood, finding it difficult to defend his original position, that fusion with 
nitre will remove the copper from bismuth, now follows the lead of the Editor 
of this Journal, who appears to think he completely settles the matter by re¬ 
minding me, in an editorial parenthesis, that “copper is precluded by the 
Pharmacopoeia tests.” In passing, I may perhaps be permitted the opinion, 
that it would have been more fair,-and—shall I say?—more courteous, to have 
allowed my answer to Mr. Wood to appear as I wrote it, unaccompanied by the 
embellishment of an editorial criticism. As, however, the Editor has chosen to 
pronounce an opinion even before the argument was concluded, I may fairly 
press him for something more. I do not for a moment suppose that he too 
believes that if “ the fusion with nitre be carried on sufficiently long ” the 
copper can be removed from the bismuth,except perhaps in the sense that if we 
look at the lion on Northumberland Gate sufficiently long we shall see him wag 
his tail. I therefore venture to suggest it would have been more worthy the 
reputation of a master of chemistry, and much more beneficial to his readers, to 
