AMMONIACUM, or

See also:

• GUM (Fr. gomme, Lat. gommi, Gr. Kµµ1, possibly a Coptic word; distinguish " gum," the fleshy covering of the base of a tooth, in O. Eng. gbma, palate, cf. Ger. Gaumen, roof of the mouth; the ultimate origin is probably the root gha, to open wide, seen in

GUM AMMONIAC  , a gum-resin exuded from the stem of a perennial herb (Dorema ammoniacum) , natural order Umbelliferae . The plant grows to the height of 8 or 9 ft., 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 . Ammoniacum has a faintly fetid, unpleasant odour, which becomes more distinct on heating; externally it possesses a reddish-yellow appearance, and when the tears or lumps are freshly fractured they exhibit a waxy lustre . It is chiefly collected in central Persia, and comes to the European market by way of Bombay . Ammoniacum is closely related to asafetida and galbanum (from which, however, it differs in yielding no umbelliferone) both in regard to the plant which yields it and its therapeutical effects . Internally it is used in conjunction with squills in bronchial affections; and in asthma and chronic colds it is found useful, but it has no advantages over a number of other substances of more constant and active properties (Sir Thomas Fraser) . Only the " tear ammoniacum " is official . African ammoniacum is the product of a plant said to beI Ferula lingitana, which grows in North Africa; it is a dark coloured gum-resin, possessed of a very weak odour and a persistent acrid taste .