OCR Text |
Show GOAT’S THORN, OR MILK VETCH. 655 Tragacanthis difficultly pulverizable, unless when thoroughly dried, and the mortar heated, or in frost. According to Neuman, it gives nothing over in distillation, either to water oral. cohol: alcohol dissolves only about 10 parts of 480, and water the whole. Lewis, however, more accurately observes, thatit cannot be properly said to be dissolved; for, put into water, it absorbs a large proportion ofthat fluid, increasing immensely in yolume, and forming with it a soft, but not fluid, mucilage; and although it is easily diffused through a larger proportion of water, after standing a day or two, the mucilag e subsides again, the supernatant fluid retaining little of the gum. Besides these remarkabledifferences from gum arabic in regard to brittleness, insolubility, and the quantity of water whichit thickens, I find, says Dr. Duncan, jun., that tragacanthis not precipitated bysilicized potash, and is precipitated by sulphate of GOAT’S THORN, or MILK VETCH ASTRAGALUS TRAGACANTHA. copper,’ and acetateof lead. MEDICAL USE. In pharmacyit is empl x powders into troches, and rendering tough cohesive substances pulverizable, bybeating then drying the mass. For Class XVII. Diadelphia. Order III. Decandria. T, Gen. CHar. Legumen bilocular, zibbous. Spec. Cnar. Caudex arborescent: Petioles a spine. 1yG on keeping Keeping Sa DESCRIPTION. , ~ T NE plant is small, rubby, clothed with brown fibres, and beset with strong spines. Leaves pinnated, pinne numerous, attached to a strong spinous footstalk. yellow, in close clusters. Flowers large, of a pale HUST O'R Y. Gumtragacanth is the produce of a very thornyshrub, whick Take of gum tragacanth, boiling water, eigh Macerate for twenty-four hours; then triturate carefully, that the gum may be dissolyed; and press the mucilage through linen cloth. AT... grows on the island of Candia, and other places in the Levant. About the end of June a fluid exudes from the stem andlarger branches, which dries in the sun, and is collected by the shep- herds on Mount ida, from whence it is sent to Europe under thetitle of Tragacanth. lt consists of whitish semitransparent vermiformpieces, scarcely a line in thickness, without taste or smell, Thereis also a dirty yellow, or brownish kind, which is not fit for medical purposes. mn MUCILAGE OF TRAGACANTH. = ‘ ‘ x (Mucilago Tragacanthe. L.) es, by measure : solved. Gumtragac difficultly é When maceTo effect the solusome of the water; and lually, and incorporated With the paste, by beating them together. ratedin it, it swe lls, but doe tion, it must be beaten in the rest of the water must be add |