This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
This consists of resin, lard, and yellow wax melted together. Whatever positive dynamic effects it produces, if made of pure materials, may be ascribed to the resin. it is slightly irritant, and is chiefly used as a dressing for blisters, which are to be kept open for a short time. Generally the skin will heal under it notwithstanding the irritation, to which the parts seem to become accustomed; but it sometimes produces much inflammation, and even causes the blistered surface to suppurate. it is also used as a gentle stimulant to indolent ulcers, and is one of the most efficient applications to chilblains. I know no dressing more efficient in promoting the healing of burns and scalds, when disposed to become indolent. it often occasions pain; but the healing process commences nevertheless, though previously there may have been no tendency towards it. in recent severe burns, it rather relieves than promotes pain; and is much used, in connection with oil of turpentine, in the form of a liniment, which is officinal.
Somewhat more stimulating than the above, though used for similar purposes, is the Compound Resin Cerate (Ceratum Resina Composi-tum) of the U. S. Pharmacopoeia, made by melting together resin, suet, yellow wax, turpentine, and linseed oil, straining, and stirring constantly until cool. This is known commonly by the name of Deshler's Salve.
Liniment of Turpentine (Linimentum Terebinthina, U.S., Dub.) is prepared by adding half a pint of oil of turpentine to a pound of resin cerate, previously melted. it is commonly known as Kentish's Ointment, having been originally proposed by Dr. Kentish, as an application to recent burns and scalds. Being of a semiliquid consistence, it is most conveniently applied by means of linen cloths saturated with it. Care should be taken to confine the application strictly to the injured parts. it relieves the burning pain, and produces a disposition to heal; but should be removed, when, the peculiar inflammation of the burn .having ceased, the preparation itself may become irritant.
There are many other vegetable substances, occasionally used externally for their rubefacient effect, most of which, along with this special application of them, have been treated of under other heads.
All of these have more or less of the rubefacient property, and not a few of them are habitually used. Thus, powdered ginger, cloves, cinnamon, and black pepper are frequently made into cataplasms. A good aromatic cataplasm, or spiced plaster, as the preparation is usually called, may be prepared by mixing an ounce of each of the above aromatic powders, half a fluidounce of one of the aromatic tinctures, and sufficient honey to give due consistence. This may be applied to the epigastrium in cases of vomiting, spasm of the stomach, and gastrodynia, and over the abdomen in colic; and is especially adapted to these affections in children. The fresh aromatic herbs, such as the mints, origanum or rosemary, and monarda or horsemint, may be used under similar circumstances, being thoroughly bruised, and thus made into a cataplasm. Rubefacient liniments may be prepared from volatile oils of rosemary, origanum, etc., mixed in various proportions with almond or olive oil, or from their alcoholic solutions, which may be used, especially in conjunction with anodynes, as opium, camphor, etc., in rheumatic and neuralgic pains, bruises, and sprains. But these applications have been already incidentally suggested, under the several articles described.
The stimulating gum-resins, as assafetida, ammoniac, galbanum, and sagapenum, constitute another category of gentle rubefacients, generally used in the form of plaster, and applied in chronic pains and swellings of the joints, scrofulous tumours, and other chronic tumefactions, occasionally with decided effect in promoting absorption. Officinal preparations of these substances, for the purposes mentioned, are the Assafetida Plaster (Emplastrum Assafcetida, U. S.), the Ammoniac Plaster (Emplastrum Ammoniaci, U. S.), and Compound Galbanum Plaster (Emplastrum Galbani Compositum, U. S.), the last of which, besides galbanum, contains turpentine and Burgundy pitch.
Still another category of rubefacients consists of various acrid substances, used commonly for different purposes internally, but applied also locally for their irritant effect. The most prominent of these are savine and mezereon. These are most frequently employed externally as dressings to blistered surfaces, in order to keep them discharging, which they do effectually, if possessed of all their original powers; but, as found in the shops, they have often become so much deteriorated that they not unfrequently fail. They are used in the form of cerates or ointments, which arc officinal. Savine Cerate (Ceratum Sabina, U. S.; Unguentum Sabina, Br.) is made by incorporating three troyounces of powdered Savine with a pound of resin cerate; Mezereon Ointment (Unguentum Mezerei, U. S. 1850), by digesting bruised mezereon with lard and wax, till its active properties are extracted.
Alcohol, Ether, and Chloroform are also locally irritant, and are often employed, especially the first two, with a view to a rubefacient impression on the surface. Alcohol is generally applied by friction, in the form of heated brandy or whisky. Ether, when used for this purpose, must be prevented from evaporating; as otherwise it would produce the opposite effect of refrigeration by its volatilization. All these substances, though treated of elsewhere, are mentioned here, in order that the reader may have presented to him the whole class of rubefacients in one view.
Different species of Ranunculus possess acrid properties, which render them applicable to the purposes of the rubefacients and epispastics. One of them, R. bulbosus, has been retained in the secondary list of the U. S. Pharmacopoeia; but all the more acrid species may be used. They are commonly known by the name of buttercup, from the character of their handsome yellow flowers. Both the herb and bulb or cormus may be employed. They must be used fresh, as they lose their virtues by drying. Their acrimony is also dissipated at a boiling temperature. internally, they violently irritate the stomach, and may even prove fatal. Bruised and applied to the skin, they often excite severe inflammation, and sometimes vesication; but there is great difference of susceptibility to their influence in different individuals; some being little affected, while others are acted on with unexpected violence. Sometimes deep ulcers are produced in the latter individuals. These are not, therefore, medicines for common use; but every physician practising in the country should be acquainted with their properties; as circumstances may occur in which it may be important that he should avail himself of them.
Another plant occasionally used advantageously as a rubefacient is the common nettle or Urtica dioica, an herbaceous perennial, indigenous in Europe, but naturalized in the United States. The sharp hairs of the plant, when the herb is applied to the skin, especially when struck upon it with some force, produce a severe irritation, attended with hard, whitish elevations, or wheals, very much resembling the eruption denominated urticaria, or nettle-rash, which received its name from this very resemblance. The remedy may sometimes be usefully employed in cutaneous torpor or paralysis, and is peculiarly applicable to cases of retrocession of cutaneous eruptions. I have seen it used, with apparent benefit, in rousing a patient, torpid from the effects of a poisonous dose of opium. Under such circumstances, it aids other measures, in sustaining a certain amount of excitability in the cerebral centres, favourable to the operation of emetics.