EXTRACTS OF THE BRITISH PHARMACOPOEIA. 
307 
twelve hours ; then pack in the percolator and add more distilled water until 
the root is exhausted. Heat the liquor to 212° and strainthrough flannel, then 
evaporate by a water-bath to a proper consistence.” 
Now, the process of the London Pharmacopoeia has maceration of the 
fresh root in boiling-water for twenty-four hours, decoction of the liquid to 
one-half, straining whilst hot, and evaporating to a proper consistence. 
You will at once perceive that in the British form there are four points in 
which it differs essentially from the London, namely, the extract is to be pre¬ 
pared from the dried root, cold water is to be used in the place of boiling, and 
percolation instead of maceration, and lastly, the liquor is to be heated to 
212° Fahrenheit, in order to separate any albuminous matter, which is to be 
taken out of the liquor, by means of straining through a flannel bag, before 
evaporating it down to the consistence of an extract. 
Percolation with cold water was the process directed in the last Edinburgh 
Pharmacopoeia, and maceration with cold water in that of the Dublin; but 
the Dublin did not order the liquor to be heated before being strained and 
evaporated. There are one or two points in the preparation of this extract to 
which I may draw your attention ; in the first place, the root is to be dried 
and coarsely powdered: this part of the operation increases the amount of 
labour, for, in order to dry the root by a gentle heat, it should be first sliced. 
Now, during the drying, the root will, upon an average, lose one-half its 
weight, so that two pounds of fresh root will part with one pound of moisture ; 
I say this is the average, because the root will sometimes vary according to 
the dampness or dryness of the season or the time when it is dug up, and 
also, according to the time which may have elapsed between the taking up 
and the drying by artificial heat. It would be natural to suppose that the 
root having parted with one-half its moisture, that would be precisely the 
quantity required to macerate the powdered root before placing it in the per¬ 
colator, and so bring it to its normal state as to moisture, and just in the con¬ 
dition to yield up everything soluble in water ; but it may be observed that 
the Pharmacopoeia directs otherwise, and it is correct in so doing. 
The direction says, macerate one pound of coarsely powdered root with 
eight fluid ounces of distilled water,—just one-half; this, it is true, can scarcely 
be called maceration, for the quantity of water is not sufficient to moisten the 
powder, but nevertheless it is enough for the purpose, and if more is used, 
the mass puts on a pasty, pudding-like character, settles down and packs 
itself so firmly in the percolator, that the liquid passes through so slowly, that 
before the root can be exhausted, if circumstances as to temperature (a warm 
shop heated by gas) should assist, it is highly probable that fermentation 
will take place in the marc, and alter the character of the product both in 
quality and quantity. This little caution as to the amount of water used in 
the moistening or macerating of the root, is, I believe, important and worthy 
of attention, and more especially if extract of liquorice is likely to be made 
upon a large scale by the cold-water percolation process. In small quantities, 
attending strictly to the directions of the Pharmacopoeia, using in all about 
eight pints of distilled water for exhausting one pound of dried root, a clear 
good extract will be obtained, soluble in water and proof spirit, throwing 
down a slight deposit from the latter solution upon standing; thirty per cent, 
of moist extract will be the average product from dry root, which is equiva¬ 
lent to fifteen per cent, from the fresh root, seeing that the fresh loses one- 
half its weight in drying. It is, I think, with commercial men at all times an 
object to know the cost of producing an article : well, this extract costs, upon a 
nice calculation, about 45. Qd. a pound, and, in making this calculation, I set 
the fire used in drying and the labour of powdering or grinding against the 
fire in making the decoction and the labour of bruising. Now the average 
