Every syrup answers this purpose; for the necessary proportions, see
_Electuaria_.
IV. _To communicate an agreeable colour._ Syrup. Croci: L.—Rhæados. L.D.
(166, 168.)—Caryophylli Rubri. D.—Violæ. E. Except that of Saffron,
these syrups are rendered green by alkalies, and red by acids.
GENERAL REMARKS. The practitioner should never introduce syrups into
those medicines which are liable to be injured by the generation of
acids: I have frequently seen the _cretaceous mixture_, when charged
with syrup. Increase, instead of check, a diarrhœa; and the syrup of
poppies, from its disposition to become acescent, will often aggravate
rather than allay the cholic of infants. The syrup of Senna furnishes
the practitioner with a convenient purgative for children; that of
buckthorn is more violent, and is on that account but rarely used;
besides which, in preparing it the chemist not unfrequently substitutes
the berries of the _Cornus Sanguinea_, the Dogberry-tree, or those of
the _Rhamnus Frangula_, the Alder-buckthorn, for the Rhamnus
Catharticus; a circumstance which necessarily renders the efficacy of
this syrup variable and uncertain; it is moreover often sophisticated
with treacle and jalap. The syrup of the rose, when made with the leaves
of the _Damask_[656] rose, is gently laxative, and is well adapted for
weak children; it is however not unusual, _coloris gratia_, to
substitute the leaves of the _red_ rose, in which case the syrup will
possess astringent instead of laxative properties. In the preparation of
the syrup of poppies,[657] the directions of the College are frequently
not obeyed; it is sometimes made by dissolving the extract in syrup,
formed with coarse sugar, or even with treacle; at others, by adding
tincture of opium to a coarse syrup, in the proportion of ♏︎x to every
f℥j. In the preparation of the syrups of violets, the juice of red
cabbage is generally substituted; this is at least a harmless fraud.
NOTE. The syrups which are printed in _Italics_, are very susceptible of
decomposition, and should be kept in cool places.