CORTEX ANGOSTUR^E. 107 



The bark has a short, resinous fracture, and displays on its transverse 

 edge sharply defined white points, due to deposits of oxalate of calcium. 

 It has a bitter taste and a nauseous musty odour. 



Microscopic Structure — The most striking peculiarity is the great 

 number of oil-cells scattered through the tissue of the bark. They 

 are not much larger than the neighboiu-ing parenchjTiiatous cells, and 

 are loaded with yellowish essential oil or small granules of resin. 

 Numerous other cells contain bundles of needle-shaped crystals of 

 oxalate of calcium or small starch granules. The liber exhibits bundles 

 of yellow fibres, to which the foliaceous fracture of the inner bark is 

 due. The structure of the bark under notice has been very minutely 

 described and figured by Oberlin and SchlagdenhaufFen.^ 



Chentiical Composition — Angostura bark owes its peculiar odour 

 to an essential oil which it was foiuid by Herzog ^ to peld to the extent 

 of f per cent. It is probably a mixture of a hydrocarbon (CH'*) 

 with an oxygenated oil. Its boiling point is 266° C. Oberlin and 

 Schlagdenhauffen obtained 01 9 per cent, of the oil, and found it to 

 be slightly dextrogyre ; it assumes a fine red colour when shaken 

 with aqueous ferric chloride, and turns yellow with concentrated 

 sulphuric acid. 



The bitter taste of the bark is attributed to a substance pointed out 

 in 1833 by Saladin and named Cusparin. It is said to be crystalline, 

 neutral, melting at 45° C, soluble in alcohol, sparingly in water, pre- 

 cipitable by tannic acid. The bark is stated to jaeld it to the extent 

 of 13 per cent. Herzog endeavoured to prepare it but without success, 

 nor have Oberlin and Schlagdenhauffen met with it. The latter 

 chemists, on the other hand, isolated an alkaloid Angosturine 

 C'"H**NO". It is in thin prisms, melting at 85° and yielding a crystal- 

 lized chlorhydrate or sulphate. Angosturine turns red when touched 

 with concentrated sulphuric acid, or green if nitric acid or iodic acid, 

 or other oxydizing substances, have been previously mixed with the 

 sulphuric acid. The alcoholic solution of the alkaloid is of decidedly 

 alkaline reaction. A cold aqueous infusion of angostura bark yields 

 an abundant red-brown precipitate with ferric chloride. Thin slices 

 of the bark are not coloured by solution of ferrous sulphate, so that 

 tannin appears to be absent. 



Uses — Angostura bark is a valuable tonic in dyspepsia, dysentery 

 and chronic diarrhoea, but is falling into disuse. 



Adulteration — About the year 1804', a quantity of a bark which 

 proved to be that of Strychnos Nux Voiaica reached Europe from 

 India, and was mistaken for Cusparia. The error occasioned great 

 alarm and some accidents, and the use of angostura was in some coiui- 

 tries even prohibited. The means of distinguishing the two barks 

 (which are not likely to be again confounded) are amply contained in 

 the above-given descriptions and tests, and at length pointed out by 

 Oberlin and Schlagdenhauffen. They also described the bark of 

 Esenbeckia fehrifuga Martins (Evodia febnficga Saint Hilaire), a 



^Journ. de Pkarm. et de Chinde, 28 is also figured by Berg, Anatomischer 

 (1877), 226 ; plates I., II., in. The hark Atlas, Tab. 37. 



- Archied. Pharm. xcii. (1858) 146. 



