Description
Gum Ammoniac is a brownish-yellow gum resin which occurs in tearl ike fragments from a plant, Dorema ammoniacum, of western Asia: used in porcelain ceramics and in medicine as an expectorant and counterirritant. When soaked in hot water will yield a milky substance used by calligraphers to produce raised gold size on paper, parchment, and vellum. Reputed to produce a brighter effect than other sizes.
Originated from Central and Eastern Iran to Northern Russia. The plant grows to the height of 2½ or 3 meters, and its whole stem is pervaded with a milky juice, which oozes out on an incision being made at any part. This juice quickly hardens into round tears, forming the tear ammoniacum of commerce. Lump ammoniacum, the other form in which the substance is met with, consists of aggregations of tears, frequently incorporating fragments of the plant itself, as well as other foreign bodies.
