Its use is generally known; but the following is an easy substitute: Dissolve a pound and a quarter of fine isinglass in five pints of water; and before it cools spread it on silk in the manner above directed.

Emplastrum ad contusa Boerhaavii. bryoniae in farinam reductae ij. florum sulpri. i. hydrargyricum sulphure 3 iij. galbani puri, et s. a. soluti iv. emplastri de meliloto iv. ol. chamaemeli q. s. ut fiat emplastrum. The three last ingredients are to he melted together, and the powder stirred in. Modern practice adopts this, only using the emplastrum cerae compositum, instead of that of melilot; and one ounce of olive oil in the place of the oleum chamaemeli: it is supposed to be a beneficial application, particularly in scrofulous indurations.

Emplastrum anodynum. Take four pounds of common plaster; melt it over a gentle fire, with an ounce and a half of common black pitch. When this is to be applied, mix with each ounce, weight, half a drachm of opium, and the same quantity of camphor in fine powder. It is said to be very efficacious in relieving old pains; but the proportion of camphor and opium may be doubled.

Emplastrum attrahens. See Emplastrum cerae, under Cera.

Emplastrum vesicatorium. See Cantharides.

Emplastrum cumini. See Cuminum.

Emplastrum commune; formerly called diachylon, now lithargyri emplastrum.

Take of olive oil, one gallon; of litharge finely powdered, five pounds; boil them together with about a quart of water over a gentle fire, continually stirring till the oil and the litharge are united, and acquire the due consistence of a plaster; and if the water is wasted before the operation is finished, more water (previously heated) must be poured on.

As soon as the mixture is warm, begin to stir it: in about four hours the boiling will be completed; but to ascertain this, drop a little on a tile to cool, by which you will easily discover whether the litharge be dissolved; the boiling must be continued very gently, or the plaster will be black; perhaps boil over suddenly. If water should be added that is not very hot, the plaster will explode with violence, and be wasted; an accident which will happen with hot water, if the plaster is too hot. If the composition proves discoloured, the addition of a little white lead and oil will improve it; but if expected to be very white, true olive oil must be used.

Emplastrum nigrum Domini Sharp, seu Emplastrum ceruses. olei olivarum xij. cerae flavae ij. ss. cerussae x. Let the oil and wax be melted together, the ceruss added, and the whole boiled to a consistence of a plaster. Sharp used it as an application to diseased knees; but Kirklaad employs a plaster of red lead and oil, boiled to a dark brown colour, for the same purpose.

Emplastrum stimulans, seu ammonia, stimulant plaster, or plaster of ammonia. saponis 3 ij- emplastri lithargyri ss. ammoniae muriatae i. Let the soap and litharge plaster be melted together, and when nearly cold, the muriated ammonia, in fine powder, be stirred in. This plaster must be made at the time of application, else the alkali, set at liberty by the decomposition of the muriated ammonia, will fly off, and frustrate the intent of the remedy. In delicate and irritable skins, the quantity of the ammonia must be lessened, lest the plaster blister the part. In chronic enlargement of the joints, or tumours without inflammation; in some scrofulous affections of the knee or elbow joints; but particularly in those gelatinous swellings which frequently form on the olecranon, it has been of singular service, probably by stimulating the absorbents, and increasing their power of action.

Emplastrum saponis. Saponis ij. emplastr.

lithargyri iij. These, melted together, must be boiled to a proper consistence. It is a mild discutient, and to tumours of various kinds is considered as an useful application; but as soap is much more advantageously used in liquid forms, the practitioner will rarely be induced to apply it in that of a solid.

Emplastrum stomachicum. Stomach plaster. Now called emplastrum labdani compositum, compound plaster of labdanum.

Take of soft labdanum, three ounces; of frankincense, one ounce; cinnamon and expressed oil of mace, of each half an ounce; of essential oil of mint, one drachm: add to the frankincense, first melted, the labdanum heated, till it becomes soft, and then the oil of mace; afterwards mix"the cinnamon with the oil of mint, beat them together in a warm mortar, and keep the whole in a vessel well closed.

The plasters should be frequently renewed, and applied on the five lower ribs of the left side, towards the back. It has been supposed of use also to promote the suppuration of indolent tumours.