342 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS, 
[November 2,1872, 
PEPSIN, BISMUTH AND STRYCHNIA.* 
BY R. BOTHER. 
('Concluded from page 323.) 
The writer, adopting the syrup of pepsin acidified 
with the potassic tartrate as the basis, extended the 
series by adding the syrup of pepsin and bismuth, 
and the syrup of pepsin, bismuth and strychnia. 
Ammonio-bismuthous citrate, dissolved in four times 
its weight of water, will completely dissolve one- 
fourth its own weight of acid potassium tartrate. 
Tliis concentrated solution slowly deposits a fine 
white powder, which remains suspended a long time 
after shaking the liquid, and is again readily and 
completely soluble in ammonia. If, however, only 
about one-third as much cream of tartar is added as 
before to a more dilute solution, no separation will 
occur. The bismuth solution then has an acid re¬ 
action similar to the solution of pepsin. A mixture 
of the two solutions retains its transparency, and 
acid reaction indefinitely and undisturbed, dissolving 
strychnia with facility. The syrup of pepsin and 
bismuth is prepared by macerating 25(5 grains of 
saccharated pepsin in 6 or 7 fluid ounces of water in 
the same manner as for syrup of pepsin, and filtering 
through cream of tartar. 25C grains of ammonio- 
bismuthous citrate is dissolved in one or two fluid 
ounces of water, until the addition of a few grains of 
cream of tartar, to ensure an acid reaction. This is 
united with the filtered pepsin solution, the measure, 
if necessary, made up to 8 fluid ounces, and 12 to 13 
troy ounces of sugar dissolved in it, as above directed, 
without heat. The syrup of pepsin, bismuth and 
strychnia is prepared in all respects similar to the 
preceding, with the addition of 4 grains of strychnia 
to the above quantity. These syrups are permanent, 
and even when diluted with an equal volume of water 
containing a little alcohol, and exposed, no degenera¬ 
tion seems to take place in a moderate length of 
time. Therefore the writer believes that the above 
proportion of sugar can be advantageously reduced, 
and the syrup protected by a small proportion of al¬ 
cohol. When treated with hydrochloric acid, a copious 
precipitate soon appears. This is again perfectly 
and permanently soluble in an excess of hydrochloric 
acid; but when separated from the solution it is in¬ 
soluble in ammonia ; whereas the precipitate, with 
nitric acid, under the same circumstances, is redis¬ 
solved by ammonia. 20 grains of citric acid added 
to 1 fluid ounce of these syrups has no observable 
effect. 
The ammonio-bismuthous citrate, employed in 
some of these processes, -was prepared by a modifica¬ 
tion of the recent process of Mr. Wood. But the 
writer considers the proportion of citric acid unne¬ 
cessarily large. It is also found that the basic 
nitrate does not yield an oxide of good appearance. 
Tliis is always of a greyish or light brown colour and 
sandy character. However, the bismuthous oxychlo¬ 
ride is much more easily prepared. * Itself a very 
definite and permanent compound, it yields in every 
respect a physically superior oxide of a rich lemon- 
yellow colour. Tire writer believes that the bismu¬ 
thous oxychloride and the anhydrous oxide, as well 
as the simple citrate, should be made officinal. By 
this change the two indefinite and unstable, difficult 
and circumstantial, preparations—the basic nitrate 
and carbonate—would be most completel} 7 superseded. 
* Reprinted from the ‘ Pharmacist.’ 
Herapath has shown that fixed caustic alkali de¬ 
composes the insoluble bismuthous arsenate, with 
separation of pure bismuthous oxide and soluble 
alkaline arsenate. But the writer has found that 
bismuthous arsenate (resulting from the presence of 
arsenic in commercial metallic bismuth) is readily, 
completely, and abundantly soluble in a neutral or 
acid solution of ammonium chloride, and that the 
solution can be diluted to an enormous extent (1 to 
7000) before the arsenate is reprecipitated. There¬ 
fore, to purify bismuthous oxychloride from contami¬ 
nating arsenate, wash away the excess of hydro¬ 
chloric acid resulting from the decomposition of the 
bismuthous chloride, decant as much water as pos¬ 
sible, and to the residuary oxychloride add a mode¬ 
rate quantity of ammonium chloride and a sufficiency 
of water. After a short time remove the solution 
and supply a fresh portion. Remove this also, and 
separate the ammonium chloride complelely by 
washing. This procedure ensures an oxychloride 
absolutely free from arsenate, without any difficult}’. 
A dilute alkaline solution readily decomposes the 
basic nitrate even in the cold, but a concentrated 
alkali is necessary to decompose the oxychloride. 
This may be effected by maceration in the cold, but 
much more rapicfly with heat. The writer obtains 
ammonio-citrate by dissolving powdered metallic 
bismuth in chlorliydric acid with the application of 
heat and addition of sufficient nitric acid to oxidize 
the hydrogen of the hydrochloric acid, as seen in the 
subjoined equation:— 
2 (Bi) +6 (HC1)+2 (N0 3 H) = 2 (BiCl 3 ) f 4 (OH 2 )+N 2 0 2 
The resulting solution of bismuthous chloride is 
diluted by pouring into it a moderately large volume of 
water (about 30 of water to 1 of metal), whereby all 
the bismuth in solution is precipitated as dazzling 
white oxychloride in a very finely-divided state. The 
powder is very heavy, and subsides quickly and 
compactly, and can, therefore, be readily washed by 
decantation. 
The change is explained in the following equation : 
BiCl 3 + OH 2 = BiCIO + 2HC1. 
After several washings with large volumes of 
water, the powder is allowed to settle firmly; as much 
of the water poured off as possible, and to the residue 
an excess of potassium hydrate is added. The mix¬ 
ture is then boiled a short time, and the resulting 
yellow oxide washed by decantation. 
This oxide is now boiled with acid ammonium 
citrate, resulting in the formation of normal am¬ 
monium salt and insoluble bismuthous citrate ; which 
is then dissolved by a sufficiency of ammonia. 
The British solution of ammonio-bismuthous citrate 
is treble the strength of that used in tliis country. 
It contains 3 grains of oxide in the fluid drachm, 
equal to 0 grains of the double salt. Tliis solution 
is sufficiently concentrated to keep without the 
addition of alcohol, and therefore greatly preferable 
to the weaker solution. 
The writer, however, prefers to prepare tliis salt 
and its solution directly from the simple citrate. 
But the methods for its production have heretofore 
been too troublesome, on account of the bulky mag¬ 
ma, in the condition of which these processes 
always produced it. By the writer’s method this is 
now obtained in a compact, heavy, crystallized form, 
can be expeditiously washed, and most rapidly and 
easily dried. 
The production of crystallized bismuthous citrate 
