SCAMMONY AND JALAP. 
27 
resin is taken up, which is known by its turning milky 
with water so long as the resin is held in solution: mix the 
tincture with water, and, when the resin has entirely pre- 
cipitated, pour off the clear liquid and dry the resin until it 
is capable of being reduced to powder ; in this state it 
should weigh from forty-three to forty-five grains ; but the 
inferior scammony will yield only from sixteen to twenty 
grains from the same quantity. 
The purity of jalap may also be proved by the same pro- 
cess : two drachms of the powdered root, having a resinous 
fracture, and of a brownish gray interior, gave ten grains of 
resin, and the light and white root nine grains. 
To prove whether the scammony contained any more of 
the medicinal property after the resin was extracted, I took 
twelve grains of the residue, and no effect took place. A 
few days after, I took twenty grains of the extract of jalap 
deprived of the resin, and no action was produced. I after- 
wards took three grains of the pure resins of jalap and scam- 
mony in the form of a pill at different periods, and found 
them act as brisk purgatives, and without perceiving any 
difference in their strength. It may be necessary to state, 
that every dose was taken when the system did not require 
medicine, as a material difference in their effect would be 
the consequence if this caution were not observed, because 
the resins are rendered more nauseating and irritating by 
the presence of acid in the stomach : it is from this cause 
that children so often reject these purgatives. Alkalis, on 
the contrary, have the power of modifying the activity of 
resins by entirely suspending their griping effects — a fact 
which I proved by boiling them in a solution of soda until 
dissolved, and by taking a dose of each ; I found nine grains 
of each resin, when held in solution, equal in effect to only 
three grains of the solid resins ; their action was particular- 
ly mild, and they might be introduced into practice as a 
most agreeable purgative, since their taste was scarcely per- 
ceptible when taken in any of the mineral waters ; imme- 
