RELATION OP TI1E 
BRITISH PHARMACOPOEIA TO PHARMACOLOGY. 
13 
(Pharm. Journ. 2nd ser. vol. ii. p. 353). TJnguentum Creasoti is of the Dublin 
strength, that is, twice as strong as the London, and three times the strength 
of the Edinburgh ointments. 
TJnguentum Hydrargyri. This is still made by rubbing metallic mercury 
with lard and suet. According to Tyson (Pharm. Journ. vol. i. p. 452), it is 
best made at once from black oxide of mercury, and he recommends a formula 
for its preparation in that manner. Donovan, Guibourt, and Watt (Pharm. 
Journ. vol. iii. p. 400) also believe the efficacy of mercurial ointment to be due 
to the black oxide of mercury always present in it. Finally, Yon Bserensprung 
proved by many experiments (Journ. fiir Prakt. Chem. 1850, no. 9, and 
Pharm. Journ. vol. x. p. 554) that metallic mercury, either in the finely divided 
or gaseous state, is not capable of permeating dead or living animal membranes ; 
that on triturating mercury with various substances a small quantity of black 
oxide of mercury is formed, and that this is the sole active constituent of blue 
ointment and several other preparations; that the action of blue ointment is 
uncertain, because the quantity of oxide contained in it varies according to its 
age and mode of preparation; and lastly, that a more uniform and effective 
preparation can be made from the pure protoxide. These conclusions of Von 
Bserensprung have never, to my knowledge, been questioned, and yet the old, 
irrational process of making the officinal mercurial ointment is still adhered to. 
TJnguentum Hydrargyri JYitratis. The mixture of solution of nitrate of 
mercury, oil, and melted lard, is now to be heated until the strong chemical 
action indicated by brisk effervescence has ceased. The resulting ointment 
will be an improvement on the old London form. The process is that of the 
London and Dublin Pharmacopoeias, and is apparently that originally sug¬ 
gested by Duncan. Alsop, however (Pharm. Journ. vol. i. p. 100), came to 
the same conclusions after making many experiments. He at first proposed 
the use of almond oil in the place of the olive oil of the London formula, but 
on repeating his experiments before publishing a paper on the subject, he 
found that the superiority of the ointment he had obtained on using almond 
oil was due to the increased heat he had accidentally employed, and was in¬ 
dependent of the variety of oil. 
TJnguentum Hydrargyri Oxidi Jiubri. This ointment differs from the okl 
varieties in containing almond oil. Possibly this alteration will afford a more 
permanent preparation. Keffer (Chem. News, vol. ii. p. 258) made the oint¬ 
ment with castor oil instead of lard, and at the end of two years found it to 
be without rancidity or loss of colour. 
TJnguentum Iodi Compusitum. The iodine and iodide of potassium of this 
ointment are now. directed to be mixed together by the help of a little proof 
spirit. Rectified spirit was formerly employed, but, according to Proctor 
(Pharm. Journ. 2nd ser. vol. i. p. 11), water is better than either. 
Veratria. —The process for the preparation of this alkaloid appears to be 
good, but requires the use of a large amount of rectified spirit. Thompson 
suggested (Pharm. Journ. 2nd ser. vol. ii. p. 54S) a modification of the pro¬ 
cess now adopted, which was far more economical. 
Vina. —The wines, like the tinctures, are to be made in quantities of one 
pint. But as in the tinctures, so in the wines, there is one exception to this 
rule, that of Vinum Aloes, of which a quart is to be made at one operation. 
Vinum Ferri was formerly made by digesting iron wire in sherry wine for 
a month, the metal being gradually dissolved by the agency of the acid salts 
naturally present. When made with wine of uniformly good quality, the 
preparation was a satisfactory one, but the amount of iron in it necessarily 
varied -with the proportion of acid salts present in the sherry. An attempt 
has now been made to introduce a “steel wine ” of constant strength, by dis¬ 
solving eight grains of tartarated iron in every ounce of sherry. But a deposit 
