74 TILE OPIUM, ETC., OF THE BRITISH PHARMACOPEIA. 
156. Valerianate de Zinc. ZnO,Ci 0 H 9 O 3 ,12HO = 2415. 
Valerate de Zinc. Valeras Zincicus. Valerianate of Zinc. 
Take any given quantity of valerianic acid, which dilute with thirty or forty 
times its volume of pure water, with which mix by small portions hydrocarbo¬ 
nate of zinc, well washed and still moist, until there is a slight excess of it. 
Apply a geutle heat in a flask, and when the carbonate no longer dissolves filter 
the hot solution and allow it to evaporate spontaneously in a stove. Valeria¬ 
nate of zinc crystallizes in pearly spangles or tablets, which water moistens with 
difficulty and of which it dissolves without heat only of its weight. The 
P. B. process is the decomposition of valerianate of soda by sulphate of zinc. 
157. Valerianate d’Ammoniaque. AzH 3 HO,C 10 H 9 O 3 = 119. 
Valerate d' Ammoniaque. Valeras Ammonicus. Valerianate of Ammonia. 
To prepare this salt, place some valerianic acid in a saucer, under a bell glass 
to which a tube is adapted, and by means of this tube admit a stream of dry 
ammoniacal gas. A neutral valerianate of ammonia is thus formed, solid, white, 
and crystallizing in prisms, which are very hygroscopic. This preparation not 
in P. B. 
158. Lactate de Zinc. Zn0,C 6 H 5 0 5 ,3HO = 136*5. 
Ladas Zincicus. Lactate of Zinc. 
May be obtained by saturating, by means of heat, a solution of lactic acid 
with moist hydrocarbonate of zinc, filtering the hot liquor, and concentrating 
to requirement by evaporation. Lactate of zinc crystallizes, upon cooling, in 
brilliant needles or blades, and requires fifty-eight parts of cold and six of 
boiling water for its solution. 
(To be continued .) 
THE OPIUM, SCAMMONY, AND CINCHONA OP THE BRITISH 
PHARMACOPOEIA. 
I scarcely think that pharmaceutists attach sufficient importance to the test¬ 
ing of these drugs, and as the Pharmacopoeia now directs us to ascertain the 
percentage of alkaloids and resins, I thought a few remarks might not be con¬ 
sidered out of place. 
The variations in percentage of morphia contained in diff rent samples of 
opium, were very strikingly illustrated at the late Conference in Nottingham ; 
the average per cent, in sixteen samples exhibited being eight, and the percentage 
of each piece ranging from a trace to 13. It was also shown that the market- 
price was no criterion of medicinal value: one sample, at 14s. per lb., contained 
but a trace of morphia; another, at 15s., contained 13 per cent.; whilst a third, 
at 16s., actually contained but 7 per cent. These facts should prove to phar¬ 
maceutists the importance of ascertaining the strength of so useful a drug be¬ 
fore using it for any of the Pharmacopoeia preparations. 
The process given for estimating the percentage of morphia in opium, although 
scientific, is not, 1 think, sufficiently simple for general use. I have always 
found a modification of Thiboumary’s process* give reliable results, and it has 
the advantage of being easily and quickly worked. The process is as follows :— 
* See Pereira’s ‘ Materia Medica.’ 
