122 ORD. Rutacez. BONPLANDIA TRIFOLIATA. 
Cusparia, or Angustura bark, was formerly supposed to be the product of 
a tree growing in Africa, or the Spanish West Indies, and the first parcels 
of bark were imported from St. Domingo; but the recent travels and dis- 
coveries of Baron Humboldt and Bonpland* have led to the knowledge of 
the true place of its growth. : 
Sensible and Chemical Properties, &c. Genuine Angustura bark,} as it 
comes to market, has a bitter, and somewhat aromatic taste, which is rather 
permanent, and when chewed, leaves a sense of heat and pungency in the 
mouth and throat: its odour is peculiar, but not very powerful. Externally, 
_ the pieces are covered with a greyish, wrinkled epidermis; internally, their 
surface is smooth, and of a yellowish brown colour: it breaks with a close, 
short, resinous fracture, and is easily pulverized. . The bark, when powdered, 
and triturated with lime or calcined magnesia, emits a smell of ammonia. 
It yields its active properties both to hot and cold water; the watery infusion 
precipitates infusion of galls and yellow cinchona, and is precipitated by, 
sulphate of iron, tartarized antimony, sulphate of copper, acetate of lead, 
oxymuriate of mercury, and pure potass; but it does not precipitate gelatin. 
Sulphuric acid gives the infusion a brown. colour, and gradually a lemon- 
coloured precipitate is deposited; nitric acid deepens the colour of the infu- 
sion to a blood-red, and, after some time, produces a lemon-yellow precipi- 
tate: the muriatic acid does not affect it, Sulphuric ether takes up one part 
from ten of the powder, and when evaporated on water, leaves a greenish- 
yellow, acid resin, and renders the water milky. The alcoholic tincture red- 
dens litmus paper, and becomes milky on the addition of water. By distil- 
lation with water, the bark yields a small portion of a white essential oil ; 
hence we may conclude that Angustura bark contains resin, a peculiar va- 
niety of extractive, carbonate of ammonia, and essential oil: A species of 
Angustura bark, in some respects resembling the genuine bark, has lately. 
been introduced on the Continent. The plant which affords it has not yet 
been ascertained ; at one time it was supposed to be the produce of the Bru- 
cea ferruginea, @ common tree in-Abyssinia: this, however is not the fact, 
as, instead of coming from the neighbourhood of the Red Sea, it is brought 
* The generic name given to this tree was imposed by Willdenow in honour of Bon- 
pland, and since adopted by Humboldt; but again, by the latter, changed to Cusparia. 
+ The London College, in their Materia Medica, retain the name given to this tree 
by Humboldt, viz, Cusparia febrifuga. 
