GLASGOW CHEMISTS A>:D DRUGGISTS’ ASSOCIATIOX. 
405 
mined the formation of an exceedingly light and bulky precipitate, which, on exiimi- 
nation, proved to be entirely free from crystals, and perfectly soluble in boiling citrate 
of ammonia solution, I endeavoured to render this fact of practical value, and made a 
series of experiments which have resulted in my adopting the following formula for the 
preparation of liquor bismuthi:— 
Take of Purified Metallic Bismuth.147 grains 
Citric Acid . . -. 400 grains 
Nitric Acid, sp. gr, 1-42.G fluid drachms 
Solution of Ammonia, Ph, Br,, sp. gr. 0-959 ; and 
Water,—of each a sufficiency. 
• 
Dilute the nitric acid with an equal volume of water, and add the bismuth in fragmenls 
when dissolved, take 12 grains of the citric acid, neutralize "with ammonia, and add this- 
to the' solution of bismuth ; then add water to make two fluid ounces in all, and filter 
through a small plug of tow packed in the tube of a glass funnel, displacing with dilute 
nitric acid. Take I 4 oz. solution of ammonia, dilute with 4^ oz. of water, to which add 
the bismuthic solution with constant stirring, pour at once on a paper filter, and wash 
the precipitate thoroughly. Take the remaining 388 grains of citric acid, neutralize 
with solution of ammonia, and heat to the boiling-point; to this add gradually the 
washed precipitate, continuing the boiling till perfectly bright—taking care that the 
solution at this part of the process shall have an alkaline reation (if acid, a little solution, 
of ammonia should be added)—then dilute with water to one pint. Each fluid drachm 
contains one grain BiOg. 
In dissolving the metal, a blackish flaky deposit separates, which is best got quit of 
by filtering through tow, as directed. Paper is objectionable, on account of the quantity 
of solution it would retain. In throwing down the precipitate, care should be taken 
that the nitric acid be neutralized, and the solution give a decidedly alkaline reaction: 
solution of ammonia should be added until this result be attained ; an excess is of no 
consequence. The precipitated oxide can be readily and completely washed, the opera¬ 
tion usually occupying about eight hours. An easy and effectual method of ascertaining 
when the w'ashing is complete, is to test with turmeric paper for free ammonia: the 
nitrate will have passed away when the paper is but feebly tinged. The citrate of am¬ 
monia solution should be kept boiling during the addition of the oxide. If citrate of 
ammonia be not in excess, and the boiling continued for some time beyond complete 
solution, the ammonio-citrate of bismuth is decomposed with the evolution of ammonia, 
insoluble citrate of bismuth being thrown down. Should this take place, the precipitate 
will be completely re-dissolved on the addition of ammonia. These recapitulations 
I consider necessary, because liquor bismuthi is a preparation which, to make at all 
times successfully, requires an exact and careful manipulation ; and perhaps some of the 
above observations may save a great amount of trouble, and at the same time secure a 
more perfect preparation. 
The advantages'Of the above process may be briefly stated to be—1st, A perfect so¬ 
lution of the metallic bismuth being easily obtained, there is consequently no loss by a 
portion being carried through the process unaltered. 2nd, The precipitate being for the 
most part oxide, and therefore insoluble in water or solution of nitrate of ammonia, 
there is consequently very little loss in washing,—the largest quantity I have found 
dissolved being equal to 0-12 per cent, metal. Since so little, then, is dissolved in 
washing, and the precipitate being so readily and completely taken up by the citrate of 
ammonia solution, loss is thus reduced to a minimum which, with ordinary care, usually 
averages 1-5 per cent. The only real loss is 0-12 per cent, soluble, the rest being loss by 
contact, and therefore much depending on the delicacy and skill of the operator. In the 
formula there is two per cent, metal allowed for loss, this being in all cases quite suffi¬ 
cient. 3rd, The quantity of bismuth irrecoverable varying so little, analysis is thus ren¬ 
dered unnecessary—a point much to be desired. Messrs. Blunt and Ebert seem to think 
that it in no way detracts from the working value of the process; in fact, that it is an 
advantage to introduce an analysis. This may be the case iu the laboratory of an ana¬ 
lytical chemist; but if we remember how seldom a chemical balance to turn with 
1-100'h of a grain is to be found on the counter of a retail drug-shop—and without 
which the analysis of liquor bismuthi cannot be successfully carried out,—it will be at 
once seen that the operation is quite impracticable to most retail chemists. Analysis is. 
