To this group belong the liquid preparations: Liniments, Oleates and Collodions, and the mixtures of solids: Ointments, Cerates, Suppositories, Plasters, and Papers. The Vehicle, sometimes incorrectly called the "base," consists chiefly of fatty substances which serve as protectives or facilitate absorption. The Collodions are, however, an exception.

The solid mixtures may be classified according to their fusibility, or melting-points, because their therapeutic uses, as well as their pharmaceutical forms, are through this quality respectively determined.

Ointments fuse at the body-temperature, and therefore produce an emollient effect, or induce absorption of the medicinal substance by the system. They are applied by rubbing or inunction.

Cerates have a higher fusing-point, due to Wax they contain; the medicinal agent is not so readily absorbed, and they are therefore used to produce local effects, being spread on cloth and applied as dressings.

Suppositories fuse slowly when introduced into a body cavity, but maintain their shape at ordinary temperatures. They are for use in rectum, urethra, or vagina.

Plasters have a still higher fusibility; they do not melt, but become adhesive by the body-temperature, and are intended to produce local effects and afford mechanical support to the parts affected.

The fusibilities of these various preparations are likewise governed by the respective vehicles employed.