Cataplasms are in general extemporaneous preparations; but the following formulae were introduced into the Phar-copoeias, to fix the proportions of the ingredients.

Cataplasma Alumin1s. Dub. Alum Cataplasm

"Take the white of two eggs; alum, one drachm. Agitate them together until a coagulum is formed."

The best method of forming this coagulum is to put a lump of alum into the albumen, and beat the whole with a spatula until the coagulum forms, which must then be separated from the alum.

This is an excellent application in ecchymosis of the eye, and in ichorous ophthalmia : it should be applied between folds of muslin. It is the solution of the alum held in the coagulum, las in a sponge, which is the active part of the preparation.

1 Rose water was first made in Persia; and the Persian rose water was long the most celebrated for its excellence. 2 I have never seen any oil of elder.

Cataplasma Carbonis Ligni. Dub. Cataplasm of Charcoal

"Take of charcoal, which has been recently made red hot, and extinguish by pouring dry sand over it, and triturated into a.very fine powder, a sufficient quantity, and add it to the simple cataplasm made warm."

Recently prepared charcoal has the property of destroying foetid odours, but it loses much of this if it be allowed to cool in the open air. After it is cold it should be cleansed from the sand, powdered, and immediately stirred into the poultice, which should be made thinner than nsual. Such a poultice has been found highly beneficial in foetid and gangrenous sores. It should be renewed several times in twenty-four hours.

Cataplasma Conii. Lond. Dub. Cataplasm of Hemlock

"Take of dried hemlock, two ounces; water, a pint. Mix, and add as much linseed bruised as is required to make it of a proper consistence."

An useful application for allaying pain in irritable, strumous, and cancerous sores.

Cataplasma Dauci. Dub. Cataplasm of Carrot

"Take of the root of cultivated carrot, any quantity. Boil the root in water, until it be soft enough to make a poultice.'

This is an excellent emollient poultice, and is much used in cases of malignant and offensive sores.

Cataplasma Fermenti. Lond. Yest Cataplasm

"Take of flour, a pound; yest of beer, half a pint Mix, and expose the mixture to a gentle heat, until it begin to rise.

Cataplasma Fermenti Cerevisiae. Dub. Yest Cataplasm

"Take of yest of beer, half a pound; wheat flour, a pound. Mix, and aid the swelling of the mixture by a gentle heat."

The rising is produced by the extrication of carbonic acid gas, on which the efficacy of the cataplasm depends; and which is evolved by the heat applied to the mixture exciting the fermentative process. In this state it is applied to painful gangrenous, or foul ulcers; and soon corrects the foetor of the discharge, while at the same time it hastens the sloughing of the sores.

Cataplasma Linl Cataplasm Of Linseed

"Take of boiling water, a pint; bruised linseed, as much as may be sufficient to make it of a proper consistence. Mix.

Cataplasma Simplex. Dub. Simple Cataplasm

"Take of the powder for a cataplasm, any quantity; boiling water enough to make a warm poultice, the surface of which should be covered with olive oil."

An excellent emollient poultice, which should be frequently renewed.

Cataplasma Sinapis. Lond. Dub. Cataplasm of Mustard

"Take of mustard seed, linseed, of each in powder, half a pound; hot vinegar, a sufficient quantity. Mix them to the thickness of a cataplasm."

This cataplasm is a powerful local stimulant and rubefacient. It should be spread on cloths to the thickness of about half an inch, and applied to the soles of the feet in the low stage of typhus fever, particularly when stupor or delirium is present; and in apoplexy, coma, and other cases in which there is a great determination to the head: in deep-seated inflammatory pains. Its rubefacient effects are very quickly produced, and often so powerfully as to raise a blister on the part; but it should be taken off before this is produced.