(From mucus). A mucilage; mu-cago, a viscid glutinous liquor, made by dissolving the gum, or the soluble part of gum arabic, quince seeds, & c. in water.

Young plants particularly abound in mucilage, and seem to consist of it almost wholly. In the mallows, lintseed, and some of the cryptogamiae, as the lichens, confervae, and mushrooms, it is almost uncombined: in the milky plants it is in part separated, and united with oil and water. In every instance, it seems to be formed independent of light, which is rather an ingredient of the gluten. It is occasionally united with sugar, sometimes with oil, forming what are styled fat oils. It is insipid; soluble in water; insoluble in alcohol; coagulated by weak acids, and metallic solutions; not inflammable, but almost wholly exhaling in carbonic acid gas; changeable by the nitric acid into the oxalic, and by the muriatic into the citric acid. When diluted with water it becomes acid, and, in distillation, gives over the pyromucus acid.

The fluid, separated from the glands about the joints to facilitate their motion, is styled mucilage. See Synovia.