Angostura Bark, or CUSPARIA BARK, is the aromatic bitter bark of the Galipea cusparia, a native of Venezuela and other tropical countries. It derives its name from the town of Angostura, where it is a considerable article of commerce. It was first brought to England in 1788, although it had been in use in Spain since the year 1759. The Galipea cusparia is a small tree belonging to the natural order Rutaceæ, 12 to 15 feet high, with a trunk 3 to 5 inches in diameter. It flourishes at an elevation of 600 to 1000 feet above the sea, and its elegant white blossoms, which appear in great profusion in August, add greatly to the beauty of the scenery.
Angostura Bark is a valuable tonic in dysentery, chronic diarrhoea, and dyspepsia, but it is falling into disuse. It owes its virtues to a volatile oil, and a bitter principle, the nature of which is uncertain, to which the name Cusparia has been given. Under the name of Angostura Bitters, an essence containing angostura, canella, cinchona, lemon peel, and other aromatics, came into extensive use as a tonic; but much of what is sold is devoid of angostura, and consists mainly of cheretta or other simple tonic. Angostura contains an alkaloid called Angosturia. In the year 1804, a quantity of bark of a highly poisonous nature reached Europe, and being mistaken for Angostura Bark, gave rise to several accidents, and in consequence the use of Angostura Bark was prohibited in some countries. This spurious bark, now known as False Angostura Bark, is obtained from the Strychnos Nux Vomica, the source of strychnine, and it is readily distinguished from Angostura Bark by the following simple tests: It has no smell, has a resinous fracture, cannot be split up into small laminae, has a pure bitter taste, without aromatic pungency, and when touched with nitric acid, develops on its inner surface a deep red spot, and on its outer an emerald green. Under this test the genuine bark becomes of a dull red colour on either surface.