Dictionary.net

Demulcentia, Involventia, Obvalventia, Lubricantia, from demulcere (de, and mulcere,) 'to soothe,' 'to assuage.' (F.) Adoucissants. Medicines supposed to be capable of correcting certain acrid conditions imagined to exist in the humours. Substances of a mucilaginous or saccharine nature belong to this class. Demulcents may act directly on the parts with which they come in contact; but in other cases, as in catarrh, their effect is produced by contiguous sympathy; the top of the larynx being soothed by them first, and indirectly the inflamed portion of the air-passages. In diseases of the urinary organs, they have no advantage over simple diluents. -See Diluents and Emollients. The following are demulcents ;-Acaciae Gummi; Althaeae Folia et Radix; Amygdalae; Amylum; Avenae Farina; Cera; Cetaceum; Cydoniae Semina; Fucus Crispus; Glycyrrhiza; Hordeum; Lichen; Linum; Olivae Oleum; Sassafras Medulla; Sesamum; Sevum; Tragacantha, and Ulmus.