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CONVOLVULUS JALAPA. 
ammonia, added in excess, which throws down the Jalapine in smalf, 
white, acicular crystals. 
Chemical Properties of Jalapine. Jalapine is without 
any perceptible smell or taste, and seems to be heavier than mor- 
phina, quiniiia, or other substances of this class ; it is scarcely 
soluble in cold water, and only to a small extent in hot; ether has 
no effect upon it ; alcohol is its proper solvent. Very little trouble 
is requisite to purify Jalapine from extractive or colouring matter, for 
which it appears to have but a shght affinity. 
Medical Properties and Uses. Jalap is an active and, in 
general, a safe and effectual purgative, seldom occasioning nausea or 
much griping ; in doses of about half a drachm, it generally pro- 
duces copious evacuation. In some constitutions, particularly those 
of a bilious and hypochondriacal habit, jalap will sometimes pro- 
duce considerable griping ; in these cases it seldom operates with 
due effect as a cathartic. It is notwithstanding a safe and useful 
medicine, and may be commodiously combined with other aperients. 
Jalap may be prescribed in almost every disorder requiring copious 
and speedy evacuations, and when given with due caution, we shall 
seldom be disappointed. The watery extract, made according to 
the Dublin Pharmacopoeia, is a very mild, and almost universal 
aperient, hence well adapted for weak constitutions and children. 
The alcoholic extract (which is almost pure resin) is a very uncertain 
cathartic, and in general occasions most violent griping, and other 
distressing symptoms ; it is best given in combination, i. e. triturated 
with sugar or oil, so as to form an emulsion, when it operates with 
more certainty and much less violence. Jalap' also produces very 
considerable diuretic effects, at the same time it acts upon the 
bowels ; and we are told that the part of the jalap remaining after 
the separation of the resin, yields to water an extract, which has no 
effect as a cathartic, but operates powerfully by urine. 
Off. The Root. 
Off. Pp. Extractuin Jalapas, L. E. D. 
Pulvis Jalapae Comp. E. 
Tinctura Jalapae, L. E. D» 
