896 
PHARMACEUTICAL MEETING. 
Christison was, I believe, the first to suggest that a tendency to decomposition 
was imparted to chloroform by using, in its purification, sulphuric acid in which 
nitric acid was present. I find a statement to this effect in a short paper of 
Dr. Christison’s, published so long ago as 1850, in the ‘ Monthly Journal of Me¬ 
dical Science.’ 
Cinchona Cortex .—In consequence of the great difference existing in the 
quantity of alkaloids contained in different samples o cinchona bark belong¬ 
ing to the same species, and not distinguishable by their ordinary physical cha¬ 
racters, the Pharmacopoeia requires that the bark of each species should yield, 
by a process described, a certain minimum proportion of alkaloid. This method 
of testing the strength, and thus judging of the efficacy of natural products 
which are not of a definite chemical nature, affords, wherever it is applicable, a 
valuable means of control over the quality of commercial drugs. In the case of 
the cinchona barks it is quite applicable, but some doubts have been expressed 
as to whether the processes given in the Pharmacopoeia for testing the cinchona 
barks, are the best that could be devised for that purpose. They differ from 
processes I have been accustomed to adopt in testing barks, but the trials I have 
made of them have given satisfactory results. In one respect only would I sug¬ 
gest’ a modification of the method of operating. Instead of weighing the alka¬ 
loids as obtained by the evaporation of their solutions in ether or chloroform, 
find afterwards ascertaining that they are soluble in diluted sulphuric acid, I 
would dissolve them in the acid before weighing, then precipitate them with 
ammonia, and weigh the dried precipitate. In this manner they would be more 
easily obtained in a definite and uniform state, for in evaporating the ethereal 
or chloroformic solutions, it is difficult to remove the last traces of the solvent, 
whereas the precipitated alkaloids are very easily dried. The processes as given 
were introduced into the Pharmacopoeia in 1864. 
Emplastrum Plumhi lodidi .—This plaster was introduced into the Pharmaco¬ 
poeia at the suggestion of a member of the Medical Council, and several pro¬ 
cesses for its preparation having been suggested and tried, one was selected, 
which appeared at the time to give the best result. It has been fouud, how¬ 
ever, that the plaster made by this process, which, in the first instance is of a 
bright yellow colour, gradually becomes paler, and ultimately almost colourless. 
This obviously arises from the action of the soap contained in the soap plaster, 
which is one of the ingredients, on the iodide of lead, resulting in the formation 
of iodide of sodium. When made with resin plaster alone, or with a mixture of 
resin plaster and lead plaster, the decomposition does not occur. 
Extractum Ergotee Liquidum .—The process, by which this preparation is di¬ 
rected to be made, involves the use of a considerable quantity of ether, which 
is applied to the ergot for the purpose of depriving it of its oil before submitting 
it to the action of warm water for the extraction of what is soluble in that men¬ 
struum. The product is a solution of those constituents of the ergot which are 
soluble in water, the oil being carefully excluded ; but the method of producing 
it is considered by many persons, and I think justly, to be unnecessarily costly, 
and it has been suggested that a similar and equally efficacious preparation 
would be obtained if the exhaustion of the ergot with ether were omitted, as 
the oil is not to any sensible extent soluble in water. 
Ferrum Redaction .—This preparation is intended to consist essentially of me¬ 
tallic iron in a finely divided state, but the presence of a small quantity of 
magnetic oxide of iron is recognized, as it would be very difficult to ensure en¬ 
tire freedom from such admixture. Reduced iron is frequently prescribed, and 
much reliance is placed on its efficacy as a remedial agent. It is easily acted upon 
by the acids present in the stomach, and, if it be in a sufficient state of- purity, 
pure hydrogen gas is evolved during its solution. The most important defect 
to which it is subject is, that if not properly prepared, it may give off sulphu- 
