BLACK DROP. 
203 
frequent shaking, for two weeks. Then throw the whole 
upon a displacement filter, replacing the liquor upon the in- 
gredients until it passes off clear, which, when entirely drained 
off, measuring about two pints, set aside. 
To the ingredients in the funnel, add, a little at a time, 
Oiss. of vinegar, which, if done with care, will displace the 
remaining saturated liquor, and thus deprive the ingredients 
of all their strength, at least, that it is practical or important 
to obtain. 
The second portion of filtered liquor ought to measure 
considerably less than a pint, and to be equally clear with the 
first. To it, is to be added one pound, or if a strict adherence 
to the original formula is preferred, one and a quarter pounds 
of white sugar. Dissolve with gentle heat, and evaporate 
slowly to F. Oj. §ii>, or to a sufficient extent so as to form, 
when added to the first infusion, exactly F. Oiij. giij. of Black 
Drop. Thus prepared, it will contain exactly double the 
quantity of opium in solution, that is directed in the United 
States Pharmacopoeia for laudanum, admitting the menstruum 
to be sufficient to take up all the strength of the opium. 
The advantages which Black Drop, properly prepared, 
possesses over that by the usual method, must be evident. 
There is absolute certainty, if the opium is good, of having 
the preparation always the same; there is no waste of mate- 
rial, and the product is a rich, concentrated, aromatic vinegar 
of opium, as nearly double the strength of laudanum, as the 
solvent powers of the menstruum will admit of. More than 
this cannot be anticipated from following the unscientific di- 
rections which accompany the original domestic recipe — of 
boiling all the ingredients up together, and setting aside in 
the sun for six weeks. 
The uncertainty whether the boiling would ever be twice 
done to the same extent, the difficulty of filtering the preparation 
after the sugar has been dissolved in it, and the great waste 
of material, the product being only about half, constitute in- 
superable objections to the original method, and were the 
causes which first directed my attention to the subject. 
