UNGUENTS, or ointments, are unctuous substances, for external application, and intended to answer a variety of purposes, according to their composition. They are variously designated according to their nature and consistence. At one stage of surgery they were of a very complicated kind, as may still be seen in the so-called balsams (artificial) of the continental pharmacopmias ; but the progress of modern science leading to greater simplicity, their numbers are much reduced, and their ingredients fewer. If they are composed chiefly of wax, without resin, and of oil, with or without other more active materials, and have a consistence nearly as great as that of plasters, they are termed errata; when fats or resin are used, so that the consistence is scarcely greater than that of butter, they are termed ointments; if distilled fragrant waters or essential oils are used, they are termed pomatums, or pomades; and occasionally, if the appearance correspond, some are termed butters, or pastes, such as almond paste, which, being bland and emollient, must be carefully distinguished from some other compounds also called butters [Bussees, in Pharmacy], which aro acrid and corro sive, such as butter of antimony, or violent poisons, such as butter of arsenic. Most ointments are formed by melting together the ingre
dients, and in doing this the heat should never exceed that of tho boiling-point of water. To ensure uniformity and smoothness, tho in gredients should be carefully stirred while on the fire, and strained through a cloth while yet in the liquid state : if essential oils are used, these must be added afterwards. Soino are made by merely triturating the materials together, as in the ease of mercurial ointment. No great quantity of any ointment should be prepared at ono time, as they are apt to undergo changes, sometimes very detrimental, either by the ingredients acting on each other, or by absorbing oxygen from the air. Many should be prepared only when wanted, such as the ointment of the nitrate of silver.
The chief use of ointments is either by their emollient qualities to soften tense or hardened parts, or to sheath excoriated parts from acrid secretions or the Irritation of the air. Applied to ulcers, they may, according to their nature, besides excluding the air, promote the heal ing, if judiciously used, or hinder it if improperly used. For chapped hands or rough skins, one of the mildest and safest applications is almond-paste.