| 释义 |
tragacanth|ˈtrægəkænθ|
Also 6 tragachant, 7 tragagant, 8 tragant, -anth; see also adragant, dragant, dragon2.
[a. F. tragacante (16th c.) = It., Sp. tragacanta, ad. L. tragacantha (Pliny), a. Gr. τραγάκανθα goat's-thorn, tragacanth-shrub, f. τράγος he-goat + ἄκανθα thorn.
The gum was called in L. tragacanthum (Celsus), whence Sp., Pg. tragacanto.]
1. A ‘gum’ or mucilaginous substance obtained from several species of Astragulus (see 2), by natural exudation or incision, in the form of whitish strings or flakes, only partially soluble in water: see quot. 1875. Used in medicine (chiefly as a vehicle for drugs) and in the industrial arts. Also a similar substance obtained from Sterculia Tragacantha of W. Africa.
a. Commonly called gum tragacanth.
1573in Feuillerat Revels Q. Eliz. (1908) 199 Gum tragachant ii ounces. 1634J. B[ate] Myst. Nat. 33 With gum tragagant dissolued in faire water. 1643Steer tr. Exp. Chyrurg. xiv. 57 Mixe it with the whites of Egges and Gum Tragacanth. 1714Fr. Bk. of Rates 92 Gum Tragant per 100 Weight 02 10. 1811A. T. Thomson Lond. Disp. ii. (1818) 65 Gum tragacanth is demulcent. 1830Lindley Nat. Syst. Bot. 39 The Gum Tragacanth of Sierra Leone is produced by a species of Sterculia. 1875Bennett & Dyer Sachs' Bot. 36 Gum-tragacanth consists of the cells of the pith and medullary rays of Astragalus creticus, A. Tragacantha, and other species, transformed into mucilage.
b. Called simply tragacanth.
1601Holland Pliny xiii. xxi. I. 398 A pound of Tragacanth is worth thirteen deniers Romane. 1712tr. Pomet's Hist. Drugs I. 181 Traganth or Tragacanth, is a white curl'd Gum made like little Worms. 1875H. C. Wood Therap. (1879) 577 Tragacanth is used in medicine only in the manufacture of troches and in suspending heavy powders.
†2. Any one of several low-growing spiny shrubs of the genus Astragalus (N.O. Leguminosæ), found in Persia and neighbouring regions, which yield gum tragacanth (see 1). Obs. rare.
1601Holland Pliny xiii. xxi. I. 398 The same Iland hath the bush Tragacanth growing in it. 1741Compl. Fam.-Piece ii. iii. 373 Columbines, Spireas,..Spanish Broom,..Tragacantha.
3. attrib.
1813Milburn Oriental Comm. I. 110 Tragacanth gum, or as it is usually called gum dragon. 1836J. M. Gully Magendie's Formul. (ed. 2) 138 Tragacanth powder. 1876Harley Royle's Mat. Med. 633 Tragacanth Bushes..are small, tangled, spiny bushes, resembling stunted varieties of..furze. 1879Sat. Rev. 8 Nov. 580/1 The tragacanth draught of the ancient Sophists is tolerated.
Hence tragaˈcanthin (also contr. traˈganthin), Chem., the essential constituent of tragacanth and other gums: = bassorin. (See also quot. 1843.)
1842Brande Dict. Sc., etc. s.v. Tragacanth, An analogous kind of gum is found in other plants, and the generic name of tragacanthin is sometimes applied to it. 1843Penny Cycl. XXV. 114/1 An artificial substance prepared by boiling starch,..called tragacantin. |