534 
LIQUOR BISMUTHI ET AMMONIJ5 CITRATIS. 
Mr. Schacht admits that, in framing the advertisement to which I adverted, 
he “ argued that manufacturers would be little likely to employ this imperfect 
and wasteful process of purification, but would most likely proceed in their 
preparation of this liquid bismuth as they have hitherto manufactured the 
trisnitrate, and would consequently produce an article such as the advertise¬ 
ment described.” 
In other words, he assumed that this liquor would be always made direct 
from commercial bismuth without reference to its purity. Could a liquor so 
made, however, be correctly described as“ the Pharmacopoeia preparation ”? I 
think not. Whether manufacturers generally are likely to evade the require¬ 
ments of the Pharmacopoeia,* as Mr. Schacht implies, I cannot say ; but if 
they do, the responsibility rests upon them, and not upon the Pharmacopoeia, 
should their produce prove to be impure. That the process given for purify¬ 
ing the metal is somewhat expensive, unless the oxide of bismuth found in 
the fusion be utilized, I am disposed to admit; but this is beside the question. 
The process is easy of execution, and can be readily performed with small 
quantities of material. In like manner, the preparation of the liquor is very 
simple, and the product perfectly definite in strength. Both methods are, 
consequently, well suited to a national Pharmacopoeia, because they enable 
any pharmaceutist who wishes it, however limited the means at his disposal, 
to prepare the liquor for himself w T ith the certainty, as I believe, that the 
result will be good and trustworthy. If the manufacturer hnds that he can 
attain the same end by more economical means, he is perfectly at liberty to 
do so ; but the product must be essentially the same and in all respects as 
good as that of the Pharmacopoeia . 
Mr. Schacht further alleges, however, that his statement is substantially 
true, even if the Pharmacopoeia be strictly followed. Yet, w r ith regard to the 
■arsenic and antimony, he admits that the fusion with nitre may remove 
them, and is not prepared to adduce any facts to the contrary, but considers 
that I should have given the details of my experiments. I will at once 
supply the deficiency. Having prepared (for business purposes and not for 
experiment) several samples of the Pharmacopoeia liquor, 1 tested each of 
them by putting one fluid drachm into a Marsh’s apparatus, and holding a 
cold porcelain slab in the flame. As I obtained no stain, I regarded the 
samples as pure. Whether by refining upon this method I might have ob¬ 
tained evidence of minute traces, I cannot say. I considered my test already 
more than sufficiently delicate, because I was regarding the subject in a prac¬ 
tical light, and not from an extremely critical and scientific point of view. 
I may here observe, that I have not had the opportunity of using any 
“ museum specimens ” of metal, such as Mr. Schacht refers to ; all the bis¬ 
muth I have employed has been obtained in the ordinary way in commerce 
for the manufacture of bismuth compounds. 
With regard to the copper, Mr. Schacht, in support of his assertion, de¬ 
tails an experiment to show that the officinal process failed to eliminate 
copper when it was present in the commercial bismuth. I asserted in my 
paper that, in several experiments with bismuth, purified as the Pharmaco¬ 
poeia directs, I found no copper, excepting in one case. The test I grounded 
this statement upon was as follows:—20 grains of the metal dissolved in 
nitric acid, and precipitated by excess of ammonia, gave a filtrate which was 
entirely devoid of colour. I thought this test delicate enough for all practical 
purposes ; and I think so still. Moreover, I think every one will be able to 
* Namely, that the metal employed shall have been previously fused with nitre, and shall 
give no indication of copper by the carbonate of ammonia test. 
