Ammoniac or gum ammoniac is a yellowish substance with a
sickening, bitter taste, obtained from the milky exudate of the
injured stem of a plant (Dorema ammoniacum) found in Iran. It is a gum
resin, soluble in alcohol and ether. It is used in industry in the
manufacture of porcelain cements and in medicine as an expectorant.
When gum ammoniac is distilled, it yields a liquid, oil of ammoniac.