250 
ON THE PREPARATIONS OF SENEKA. 
Take of Polygalic acid - grs. viij. 
<£ Boiling water - f.^ss. 
" Syrup of gum arabic - - f.giss. 
Dissolve the acid in the warm water and add the gum syrup; 
one fluid-dram of this syrup would be equivalent to half a 
dram of seneka. The addition of ten drops of liquor potassse 
will supercede the necessity of the water being hot, as the 
alkaline polygalate is very soluble— while at the same time 
its activity is not decreased. 
The officinal preparation of seneka, which has received the 
most universal employment, is the decoction. It is the only 
one to be found in the British Pharmacopoeias, and this may 
be looked upon as an evidence of the low esteem in which 
seneka is held by the practitioners of Great Britain, a fact ad- 
mitted by Pereira. It is but seldom that the apothecary is 
called upon to prepare this decoction, the physician directing 
a quantity of the root, often in combination with some other 
remedies, to be placed at the disposal of his patient, with di- 
rections to pour a certain quantity of water on it, and boil for 
a given time, or until reduced to a stated measure. 
From imperfect manipulation, assisted, perhaps, by the want 
of a proper degree of comminution, the root is but half ex- 
hausted. It has frequently happened, owing to the omission 
of directions in the prescription, that the unbroken roots have 
been used to make the decoction ! 
In every case where such substances are prescribed with a 
view to their being prepared by the patient, the pharmaceu- 
tist is justified in assuming the interpretation of the prescrip- 
tion by reducing them to a proper state of division. 
When prepared by the apothecary, if time is allowed, resort 
should be had to the method of displacement which yields 
a transparent and more concentrated infusion ; but if that is 
inadmissible from limited time, or the nature of associated 
substances, maceration in warm water, (120° Fahr.) and sub- 
sequent expression, will be more appropriate. It is best to as- 
sociate with the decoction some demulcent substance to mask 
