234 
BRITISH PHARMACEUTICAL CONFERENCE. 
importance, to give an opinion on the relative merits of certain articles of this 
class of English and French preparation, from microscopical examination and 
measurement. 
In Toxicology, again, we find equally important results follow its use. In 
some cases when searching for poisonous substances which yield no reactions 
to chemical tests, such as savine, we are compelled to rely upon the micro¬ 
scope solely as our guide; and in others where chemical tests do afford evi¬ 
dence, as in nux vomica and many other characteristic vegetable structures, 
valuable collateral testimony may generally be obtained thereby. 
The question of the adulteration of drugs and articles of food is one by 
itself and beyond our province,—the Conference has a committee devoting 
itself to the subject, and the able and zealous microscopists who are working 
upon it will, we doubt not, give evidence of the value of microscopic analysis 
in this important matter. 
Having thus briefly touched upon the field which lies around it, we may 
now proceed to what more particularly appertains to our own subject, viz. 
the Application of Microscopical Research to Pharmacy. To seek to draw a 
well-defined line between pharmacy, and chemistry on the one hand, or ma¬ 
teria medica on the other, would be a hopeless task, and it is one which we 
shall not attempt. Some of the examples named in a former paragraph, such 
as the observations on carbonate of magnesia, might be considered as belong¬ 
ing to any one of the three subjects ; but there are still certain phenomena 
observable with the microscope which come more properly under the head of 
pharmacy than either of the others, and it is to these that we would address 
ourselves. 
The phenomena alluded to are those resulting from ‘pharmaceutical pro¬ 
cesses , viewed especially with reference to the condition in which constituents 
of drugs exist in their preparations. 
It was originally our intention to have communicated to this meeting a 
summary of the results of a series of investigations comprising the examina¬ 
tion of the preparations of a considerable number of drugs, but circumstances 
have prevented our bringing the work to that state of reasonable complete¬ 
ness which the Conference has a right to expect of the papers presented to 
it, and we have consequently to ask their acceptance of an instalment only, 
and this instalment is offered, rather as a preliminary research illustrating 
the mode of operating than with any more ambitious aim. 
We have chosen for the particular subject of the present communication, 
the various preparations of opium. Whether regarded in respect to their 
importance in the practice of medicine, their variability in strength and cha¬ 
racter, or the peculiar conditions in which the active matter exists in the 
crude drug, no better subject could be found for the purpose in view. 
Opium, as is well known, is an extremely composite substance, being a 
pasty mass formed of resinous, gummy, extractive and albuminous matters, 
containing a larger or smaller percentage of certain active principles diffused 
through it. These principles are morphine, narcotine (with its two homo- 
logues), codeine, narceine, meconine, thebaine, and papaverine, either existing 
free or in combination with meconic, sulphuric, or other acids, the sum of the 
crystalline constituents, exclusive of inorganic salts, contained in good sam¬ 
ples of the drug being from twenty to thirty per cent, of its entire weight. 
Any preparation, exactly to represent opium, must contain the whole of these 
principles, as indeed the tincture may be said fairly to do. 
It has however been shown that some of the principles are inert, and others 
even deleterious in their action, and we have consequently had a class of pre¬ 
parations introduced which are understood to be of superior efficacy, not 
