86 PROCEEDINGS OF SOCIETIES. 
have had opportunity of testing, is that made by Mr. Morson, of 
London. Of three other makes which we have examined, one is 
largely charged with resinous matter, and the proportion of 
crystalline constituents is so minute that we are satisfied its 
activity must be very small; another gives a few morphine crystals, 
a good deal of narcotine, and more narceine; a third is chiefly re- 
markable for its lack of everything crystalline. 
There are certain preparations, to which we must next allude, 
which give little or no evidence as to the active matters they hold 
in solution by crystallization on evaporation. As examples, we 
may instance vinum opii, amongst officinal, and Braithwaite’s 
black drop, nepenthe, and a fluid sold as “solution of bimeconate 
of morphia,” amongst proprietary formule. That there should 
be exceptional cases in which the reaction to a certain peculiar set of 
tests is doubtful, is only what might have been expected, and it can 
searcely be regarded as a weak point in their application. Scarcely 
any chemical test we use but is open to some contingency of the 
same sort, but as long as we know the conditions of uncertainty, 
it is no drawback to its employment; it only becomes necessary 
that these conditions should be investigated, and comparison be- 
comes easy. 
We have found that when opium is exhausted, the liquor eva- 
porated to an extract, and this extract redissolved in alcohol, that 
the tendency to crystallize is very much lessened or entirely 
destroyed. The cause of this we are not yet able to explain 
with certainty, but may state the fact as one which we have 
noticed in relation to every sort of opium we have worked upon. 
It will account for the very sparing indications of crystalline 
principles from all preparations made by redissolving in alcohol a 
once-formed extract. The residue not taken up by alcohol in the 
experiment is readily soluble in water, and contains certain erys- 
talline matters which we have not yet examined sufficiently to 
report upon. Again, the subacid viscid matter left on evapo- 
rating wine prevents crystallization, consequently vinum opii 
gives a clear non-crystalline extract; we believe this also to be 
the reason why one of the proprietary preparations named yields 
the same result, as it seems to us to be a mere solution of mor- 
phine or one of its salts in wine, and not to be made direct from 
opium. The well-known “black drop” gives no crystals upon 
evaporation, but in their place a peculiar deposit, consisting of 
an amorphous, almost opaque fzeculence. This is probably owing, 
in great measure, to viscid matter held in solution, which on eva- 
poration becomes insoluble through some change and is precipi- 
tated, carrying down with it the active matter. We know too little 
of the solvent employed to speak very positively, but if the com- 
monly received theory be true—that it is made by a fermentation 
process, in which impure mallic acid is concerned—we can readily 
understand how viscid organic matter may be present in sufficient 
quantity to produce the result alluded to. 
