Remedies of a liquid nature, designed for external application.
Under this generic term, which strictly signifies a _wash_, may be
comprehended several species of medicines, calculated for the fulfilment
of different indications, as EMBROCATIONES, COLLYRIA, FOMENTA,
LINIMENTA, &c. In some instances these applications are entirely local
in their effects, as where a morbid action of the skin is changed by a
stimulating lotion, as exemplified in the cure of Psora by the
_decoction of Hellebore_, or the relaxed vessels of the tunica
conjunctiva of the eye, by an astringent collyrium; in other cases, they
operate upon parts not in contact with the remedy, through the medium of
sympathetic communication, as where cholic and disorders of the bowels
are abated by the application of warm fomentations to the surface of the
abdomen, or where paralytic affections are relieved by pumping cold
water on the part affected.
EMBROCATIONES. These, as the term[307] denotes, are compositions of
spirit, decoctions, infusions, or other liquids, applied by _sprinkling_
or rubbing them on an affected part.
LINIMENTA[308] are understood to differ from embrocations in
consistence, the former being of an oily, or mucilaginous density, which
increases their efficacy by imparting a certain emollient power, in
addition to their other virtues. In popular language, however, liniment
and embrocation are generally considered synonymous terms. They
constitute a valuable class of remedies, and the observations which Dr.
Percival has offered on their utility well merit the attention of the
medical practitioner. “Volatile and antispasmodic liniments are highly
useful remedies, and it is to be lamented that external applications of
this kind are not more frequently employed, for there is just reason to
apprehend that powerful effects might be expected from them in various
diseases.” In chronic affections of the viscera, such applications
appear highly serviceable, not only from the friction to which they give
origin, but from the influence of that species of sympathy which appears
to depend upon the mere proximity and continuity of parts, and which, as
Sir Gilbert Blane has observed, is particularly displayed “in the
containing on the contained parts, as that of the integuments on the
subjacent viscera.”
COLLYRIA[309].—Liquid applications to the eyes. The Pharmacopœia
Chirurgica contains several different formulæ for lotions of this kind,
some of which are simply astringent, while others combine also the
virtues of a stimulant.
CATAPLASMATA.[310] _Poultices_, or _Pultices_.
External applications of a pulpy, and somewhat coherent or tenacious
consistence.
They are generally extemporaneous preparations, and are calculated to
answer several different indications, viz.
1. As STIMULANTS, e. g. _Cataplasma Sinapis_, L. D. which generally
inflames the surface to which it is applied so much as to raise
blisters; common salt also, _muriate of soda_, constitutes the
active ingredient of a poultice which has lately been brought into
considerable repute for the reduction of indolent strumous
swellings and enlargements of the glands.[311]
2. ANTISEPTICS—_Cataplasma Fermenti_, L. (see p. 159.) A powerfully
antiseptic cataplasm may be also made by stirring finely powdered
charcoal into a common linseed meal poultice. A cataplasm of the
boiled carrot, beat into a pulp, has been likewise found very
effectual in sweetening foul ulcers.
3. SEDATIVES. The most efficient of these are composed of _Conium_,
_Digitalis_, or _Hyoscyamus_, and are eminently serviceable in
cancerous and scrophulous sores of a highly irritable and painful
nature, to diminish their sensibility and correct the acrid
discharges. See _Form. 18_.
4. REFRIGERANTS. In the formation of a cataplasm for this purpose we
must avoid the introduction of substances that are slow conductors
of caloric; suppose for example our object is to apply the
_sub-acetate of lead_ in this form, it will in such case be
judicious to mix the linseed meal, with oatmeal, or crumb of
bread; for if the former substance be used singly, it is liable,
from its tenacity, to become hard and dry, and in that state to
augment the temperature which it was designed to diminish.
5. EMOLLIENTS.—(The _modus operandi_ of these agents is explained at
p. 142.) For which purpose the common farinaceous poultice is the
most eligible, made by soaking slices of bread in milk, and
simmering them together over a gentle fire until they are reduced
to the proper consistence, which ought to be such as to prevent
its spreading farther than is designed, and yet not so hard as to
occasion any mechanical irritation; the whole is then to be beat
smooth with a spoon, and applied as warm as the patient’s feelings
will readily admit. Some practitioners have doubted the propriety
of milk as an ingredient in this composition, and have preferred
water as an excipient, not only because the former is very liable
to turn sour, but because it does not possess greater powers as an
emollient than water; the observations of the editor of the
Pharmacopœia Chirurgica upon this question are judicious, and
worthy our notice; “the objection,” he says, “will certainly hold
good whenever stale milk is made use of, or if the same poultice
be kept too long applied; but if the milk be fresh, and the
poultice renewed night and morning, we do not know any thing that
occasionally gives such ease and comfort to the patient as this
form of cataplasm. If water be substituted for milk, the poultice
is seldom of sufficient tenacity; it is true that this
inconvenience may be remedied by the addition of a little linseed
meal, but in some instances the meal appears to fret and irritate
the skin so much, that patients undergo considerable uneasiness
from this cause; an objection to which the cataplasm of bread and
milk is seldom subject, especially if it be not applied too hot.”
Every substance, whether liquid or solid, may become an ingredient in
this species of composition, and although judicious and
experienced surgeons have of late very considerably improved the
form of their cataplasms, yet the principles of medicinal
combination, which it has been the object of the present work to
investigate and expound, will suggest many important hints for the
farther extension of their utility; and although the direction of
them is more frequently left to the nurse than to the medical
practitioner, yet in adapting them to each particular occasion
some share of chemical address may be necessary; we have already
seen that attention must be paid to the selection of ingredients,
with respect to their powers of conducting heat, and it is evident
that care must be taken not to reduce into pulp, by decoction,
substances that contain volatile principles; while in the
preparation of active liquids to be subsequently mixed with
linseed meal, it is equally evident that we must be directed by
the chemical nature of their composition.