GLASGOW CHEMISTS AND DRUGGISTS’ ASSOCIATION. 407 
have found the quantity of copper present in different samples of bismuth to vary from 
■0'04 to *1 per cent. 
Iron is but seldom found in commercial bismuth. When present, on ammonia being 
added to the nitric acid solution, it is thrown down along with the oxide of bismuth 
giving the precipitate a yellovrish colour, which renders it unfit for the preparation of 
liquor bisinuthi. On the solutiqn of the bismuth oxide in citrate of ammonia, the oxide 
of iron is likewise dissolved, and forms the well-known salt ammonio-citrate of iron 
which communicates a jellow colour to the liquor. Iron must therefore be separated 
when the bismuth is in a metallic state. This is done, as directed for arsenic, by fusing 
with nitrate of potash, the foreign metals becoming oxidized and separated from the 
metallic bismuth. 
From the above, it will be seen to be quite superfluous to employ an expensive salt 
of bismuth, which cannot in any way be superior to the metal, either in furnishing a 
more pure liquor, or in convenience as regards complete solution. In fact, in this latter 
respect, the salt is decidedly inferior, it being almost impossible to get the requisite 
quantity dissolved in the nitric acid; besides, the process followed in the preparation of 
the oxide for liquor bisinuthi is essentially the same, as regards purification, as in the 
preparation of the subcarbonate, viz. solution of the metal in nitric acid, then precipi¬ 
tation—in the one case with a free alkali, and in the other with an alkaline carbonate,_ 
then careful ivashing. So that since it is so easy to get the subcarbonate pure, there 
nan be nothing to hinder the separation of impurities from the oxide. 
Subcarbonate of bismuth is sometimes adulterated with carbonate of lead, which, if 
existing to any extent, proves a source of much annoyance. The occurrence of impu¬ 
rities in the metal, other than those just mentioned, is exceedingly rare,—perhaps the 
only other being cobalt; but it is so seldom found, and is of so little consequence, that 
I think it unnecessary to do more than mention the name. There being so little facility, 
the wilful adulteration of metallic bismuth is almost unknown. 
It has been said that a solution of bismuth, containing one grain BiOtj to the 
•drachm, will keep but a short time, being liable to decomposition. Mr. Tichborne 
is of opinion that the cause of this is, that when ammonia (as Mr. Bartlett directs) 
is added (instead of excess of citrate of ammonia) to the citrate of bismuth, a 
more basic compound ia formed, wdiich is prone to decomposition even with the 
addition of spirit; avhile Mr. Ebert says, the change is not attended by the deposition of 
a basic salt, but by the formation of humus, and tlie liquid acquiring, meanwhile, a dis¬ 
agreeable taste and smell. I have found that if a solution of ammonio-citrate of bis¬ 
muth, having no excess of citrate of ammonia, nor free ammonia in solution, be exposed 
to the air for some time, a deposit will form, not of a more basic salt than the ammonio- 
citrate, but simply citrate of bismuth thrown down on account of loss of ammonia, in 
the same manner as before noticed in boiling the liquor after the solution of the oxide. 
In order to prevent this deposit, it is necessary that the solution shall be made alkaline 
with ammonia, and that an excess of citrate of ammonia be present. In the process 
given these conditions are complied witli, so that it is impossible that a deposit of citrate 
can separate. As to the decomposition noticed by Mr. Ebert, this must have been 
caused by the use of impure citric acid, or water containing organic matter. Only on 
■one occasion have I noticed the formation of humus, and then the liquor was made with 
“so-called” distilled water. Since that time I have always employed “ Loch Katrine,” 
and have never experienced the least annoyance in consequence. As a nrecaution 
against decomposition arising from accidental impurity, I employ 400 grains of citric 
acid—which is greatly in excess of the quantity required to form the bismuthic salt, and 
is quite sufficient to preserve the liquor, even should the citric acid or water be slightly 
contaminated; it at the same time ensures a perfectly bright liquor, W'hich is difficult 
to obtain if the equivalent only of citric acid be employed. 
Liquor bisinuthi is compatible, and may be given in combination, with tinctures of 
hyoscyamus, belladonna, and stramonium seeds; the tonic infusions, dilute solution of 
potash, aqua camphorm B. P.; Murray’s fluid camphor, if the liquor bismuthi be in ex¬ 
cess ; solution of morphia, if 7ninus acid, hydrochlor. ; or, if the acid be neutralized, with 
ammonia; and the alkaline carbonates, potash, soda, and ammonia, all of wliicli occa¬ 
sion no precipitate. In prescribing hydrocyanic acid with liquor bisinuthi, it should 
be remembered that the acid combines with the free alkali to form bydrocyanate of 
ammonia. 
