December 28,1872.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
501 
NOTE ON THE OCCURRENCE OF SILVER 
IN THE PHARMACOPEIA PREPARA¬ 
TIONS OF BISMUTH. 
By Charles Ekin, F.C.S. 
II. 
Having found, as lately published in the Journal,* 
that silver is a frequent adulterant of commercial 
Bismuth; Subnit., it occurred to me to see if it is 
also to be found in the Liquor Bismuthi as met with 
in our Pharmacies. I again procured twelve samples 
from first-rate London and country houses, and, not 
to weary you with details, I found that two contained 
a large amount of silver, one sample a very appre¬ 
ciable trace, and that the remaining nine, so far as 
silver is concerned, were pure. 
On communicating with the makers of the two first 
samples, I find that they were made strictly B.P., 
and the makers had not the least suspicion of the 
presence of silver. 
I have also examined three samples of commercial 
metallic bismuth, two of which contained both silver 
and copper, and two samples sent out as Bismuthum 
Purificatum, B.P., both of which also contained silver 
and one copper as well. The sample of commercial 
bismuth which contained neither silver nor copper 
contained lead. 
From my recent experience, I am inclined to 
wonder that only 25 per cent, of the samples 
examined contained silver. Mr. Umney’s statement, 
in his paper published in the Journal of the 23rd 
ult., that " perhaps the officinal method is seldom 
resorted to for the production of the liquor,” probably 
furnishes the explanation why this is so. Still, if 
we remember that these were all picked samples 
where we might fairly expect unexceptionable purity, 
it must be confessed that the bismuth preparations 
of the Pharmacopoeia, as at present met with in 
commerce, are far from being satisfactory. 
It is only just to Mr. Schaclit, of Clifton, the 
inventor of the fluid preparation, to say that the 
liquor as prepared by him is invariably free not only 
from silver, but also from copper, antimony, and 
arsenic, and that in his, prescribers have at all events 
one preparation that they may at all times depend 
upon. 
COWS’ MILK AND THE BEST METHODS OF 
DETECTING ITS ADULTERATIONS. 
BY GEORGE BROWNEN. 
The article on milk by Mr. Ekin in the last issue 
was an able introduction to the subject of milk 
analysis. It is, however, incomplete, and I am, 
therefore, led to supplement it with a few remarks 
from my own experience with London milk. No 
trustworthy analysis of milk can be performed which 
leaves the albumenoid nitrogen unestimated. The 
process of Wanklyn has not only been adapted to 
the analysis of cows’ milk, but an attempt was made 
only a short time since by the same test to connect 
certain forms of disease with the poorness of human 
milk. I have found very little difficulty in using the 
test myself in examining cows’ milk. The estima¬ 
tion of the solid residue of milk is a more difficult 
operation. Casein and fat are not easily dried un- 
less a known qu antity of some inert substance be 
Sec ante, p. 381 
Third Series, No. 181. 
used to divide the mass; the heat also requires care¬ 
ful regulation to prevent decomposition. 
A quick and reliable method of calculating the 
fat in milk is by means of Vogel's lactoscope— a glass 
cup the sides of which are parallel, and about 5 of 
a centimetre apart—its action depends on the amount 
of milk required to be added to a known quantity of 
water to obscure a strong light. A little experience 
with the instrument soon decides a twofold question, 
viz., whether cream has been removed or the milk 
is rich in butter. 
Mr. Brown’s use of the copper test for glucose is 
a step in the right direction, as lactin is the most 
invariable constituent of genuine milk; but his test 
requires a little modification, as the results with 
milk are sometimes rather too high. I have adopted 
successfully the following modifications of Dau- 
brawa’s method;—Alix two volumes of alcohol sp. 
gr. -833 with one volume of the milk; filter off the 
coagulated butter and casein ; a spirituous solution 
of milk-sugar is thus obtained; every increase of 'OO-f 
above sp. gr. *905, the sp. gr. of the alcohol and water of 
the milk indicates about 1 per cent, of milk-sugar. 
Evaporate the solution to a syrupy consistence, dilute 
until distilled water, and estimate the sugar by the 
copper test. An odorous or volatile reducing agent 
sometimes present in milk is thus got rid of. 
The butter on the filter may be separated from 
the casein by any appropriate solvent and estimated. 
Although the microscope cannot be relied on for 
the determination of fat globules, it is a valuable 
instrument in cases of diseased milk; misshapen 
globules, pus-like bodies and bacteria may thus be 
identified, which elude every other test. I had a 
sample of this kind of milk a short time since, and 
I afterwards obtained confirmatory proof that the 
cow was diseased. 
[*** The difficulty referred to has probabl} r in 
some cases originated in the taking of an unneces¬ 
sarily large quantity of milk for determinations of 
solid residue, 30 to 100 grammes having been re¬ 
commended by Goppelsrbder for this determination. 
When so large a quantity is taken the operation of 
drying is very tedious and uncertain. If, however, 
a much smaller quantity of milk (five grammes, for 
instance) be employed the drying may be very readily 
accomplished, especially if a shallow platinum vessel 
be used to contain the milk during the evaporation. 
There is no necessity for the employment of sand 
or other porous material, which, indeed, is calculated 
to introduce error.— Ed. Pharm. Journ.] 
THE CHINESE MATERIA MEDICA. 
In a recent number* we mentioned the fact that a 
committee of the French Academy of Medicine had 
made a report upon a manuscript work by M. Dabry 
de Tliiersant, French consul in China, and Dr. 
Leon Scmbeiran upon tliis subject. The work is en¬ 
titled ‘ Etudes sur la Matiere Medicale des Chinois,’ 
and from the report, which was read by M. Gu'bler, 
on November 19th, the following notes are ex¬ 
tracted :— 
In drawing up the present work, the authors have 
been able to take advantage of the labours of their 
predecessors in the same field, such as Tartarinov, 
See ante, p. 448. 
