472 
PREPARATION OF LIQUOR BISMUTHI. 
1. Teroxide of bismuth, though recently precipitated, is hut sparingly soluble in 
citrate of ammonia, even at the boiling temperature. The presence of a portion of 
nitrate of ammonia, through insufficient washing of the teroxide, will effect a solution. 
2. A neutral solution of citrate of bismuth, obtained by means of citrate of ammonia 
and ammonia, or by ammonia alone, of such strength that a fluid drachm contains one 
grain of teroxide of bismuth, is prone to decomposition. This change is not attended 
by the deposition of a basic salt, but by the formation of humus: the liquid acquiring, 
meanwhile, a disagreeable smell and taste, which totally unfit it for use. 
This is prevented by the addition of alcohol, whereby it is preserved indefinitely. A 
concentrated solution appears to keep well without this addition of spirit. 
3. Mr. Blunt’s assertion that, by Mr. Bartlett’s process, a large loss of citrate of bis¬ 
muth is incurred, is erroneous, and must have arisen from the employment of nitric acid, 
sp. gr. 1-5 (Ph. Br.), instead of that of the sp. gr. P42 (U. S. Ph.). Another inac¬ 
curacy occurs in the direction, to «add solution of potassa until the mixture is only 
faintly acid before this point of saturation is reached, the precipitate, first formed, 
will be entirely redissolved. _ When only sufficient potassa is added to neutralize the 
nitric acid, the citrate of bismuth is precipitated: an excess of the alkali over this 
quantity dissolves the citrate of bismuth, the solution still having an acid reaction. 
Even when the potassa is employed in atomic proportions, the yield of citrate of bismuth 
is no larger than is obtained by precipitation with citrate of potassa. The process 
recently suggested by Mr. Tichborne (before alluded to) I consider highly objectionable, 
because of the presence of nitrate of ammonia. A little more than one grain of the 
latter salt being administered with every grain of teroxide of bismuth, such an addition 
could scarcely fail to interfere injuriously with the therapeutical action of the bismuth. 
Though I have employed Mr. Bartlett’s process many times, and with uniform success, 
I prefer a modification of it, embodying the idea of Mr. Blunt, i. e. in dissolving the 
citric acid in the solution of nitrate of bismuth, and adding a sufficient quantity of 
potassa to exactly saturate the nitric acid employed; the advantage being that the 
citrate of bismuth thereby produced is more readily washed, and is more rapidly and 
completely dissolved by ammonia. 
The process is as follows:— 
Take of Subcarbonate of bismuth, 1 trov oz. 
Citric acid (in powder), 420 grs. 
Nitric acid, sp. gr. 1-42, li troy oz. 
Pure caustic potassa, 450 grs. 
Distilled water, 
Alcohol, each, a sufficient quantity. 
Dissolve, by gradual addition, the subcarbonate of bismuth in the nitric acid, and, 
when effervescence has ceased, dilute the solution with H fl. oz. of distilled water; now 
add the citric acid, and stir until it is dissolved. In 8 fl. oz. of distilled water dissolve 
the caustic potassa, and add this gradually to the acid solution. Permit the mixture to 
stand for six or eight hours, then transfer to a moistened paper filter, and wash the pre¬ 
cipitate until the washings no longer contain nitrate of potassa. Transfer the still moist 
magma to a dish, and add, very gradually, water of ammonia until the precipitate is 
dissolved, and a neutral solution is obtained. Dilute this solution with an equal volume 
of distilled water, and treat fl. oz. of the liquid with hydrosulphate of ammonia, in 
slight excess; wash the precipitate on a tared filter, dry on a water bath and weigh. 
Multiply the weight of the sulphide of bismuth by the fraction -908, to determine its 
equivalent in teroxide of bismuth. Apply the same ratio to the remainder of the liquid, 
and dilute it to such an extent that 1 fl. drm. shall contain 1 gr. of teroxide of bismuth, 
-g- of which measure must be made up with distilled water, and the remainder with 
alcohol. The ^average product of liquor bismuthi, from 1 troy oz. of subcarbonate of 
bismuth, was 50 fl. oz., indicating a loss of bismuth amounting to 7 - 6 per cent. 
This loss is occasioned by the slight solubility of citrate of bismuth in the washings, 
and though this portion may be recovered, it is too small in amount to compensate for 
the time and trouble necessarily expended in its separation.— Amer. Journ. Pharm. 
January , 1866. 
