ON FLUID EXTRACT OF VALERIAN. 
85 
They mostly contain, as it is well known, a variable 
amount of sugar; but the term may, I conceive, be with 
more propriety applied to those, where, as in the case of 
the solid extracts, this ingredient is wanting. 
Of the fluid extracts now in use, the most common, as 
those of sarsaparilla and senna, will not materially suffer 
by the action of heat in concentration, but in the present 
instance we have a volatile principle to extract, therefore 
the mode of procedure must be adapted to the peculiar 
subject under consideration. The first point is, what is 
worthy of extraction in the root. Secondly, the adoption 
of a standard of strength so important to prescriber and 
apothecary. From the best analysis of this root, viz : that 
by Trommsdorf, we have the volatile oil containing the 
acid, resin, bitter extractive, and other matters of no import- 
ance in a medicinal preparation. The oil and acid are 
very readily and effectually taken up by ether — resin by 
alcohol — and bitter extractive by water — hence the three 
menstrua are employed. 
The form of apparatus best adapted, is the common dis- 
placement funnel, having the top secured by bladder, and 
a receiver fitted so as to prevent as much as possible the 
escape of the ether whilst acting on the root. 
The standard of [strength; I have adopted, is eight troy 
ounces of the root to the fluid pint of the extract ; it was 
my original intention to have given a recipe, in which the 
strength of an ounce of the root would be representee^ by a 
fluid ounce of the extract; but owing to the destruc'/ive in- 
fluence of heat on evaporation, without which the fluid 
seemed incapable of retaining so large an amount of sub- 
stance in solution, I was induced to abandon it, and think 
the above strong enough for all eases. The medium dose 
is a teaspoonful, containing, in solution, the active principle 
of thirty grains of the root. 
In making this, as all other preparations of valerian, the 
selection of a prime article of root is a point of great impor- 
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