ANGOSTURA. 109 



the wood, fragments of which are frequently found upon it. A 

 drop of nitric acid colours this inner side of the bark a very dull 

 red. The bark of Stryclmos Nux Vomica, containing Brucia is 

 turned a hright hlood-7^ed on the addition of a drop of nitric acid. 

 The fracture of the true bark is short and resinous, showing white, 

 angular points which are deposits of calcium oxalate. 



The peculiar odour of Angostura bark is due to an essential oil, 

 discovered by Herzog,* who obtained it in the proportion of f per 

 cent. The absolute content of essential oil in the bark has since 

 been found by Messrs. Schimmel & Co., to be I'o per cent. The 

 oil is yellow, rapidly assumes a dark tint when exposed to the air, 

 has an aromatic odour and taste, possesses the sp. gr. of 0-936 at 

 15^ C, is soluble in ether, alcohol, petroleum ether, chloroform, 

 and glacial acetic acid. It has an acid reaction. It begins to boil 

 at 153^ C, the greater portion passing oyer between 200^ and 

 220^, and on redistillation to a great extent at 203^^ C. (Bekurts 

 and Wehring). 



The bitter principle contained in the bark was discovered by 

 Saladin in 1833, and termed Cusparine ; this is a neutral crystal- 

 line body, melting at 45^ (J., soluble in alcohol and in acids, but 

 sparingly so in water, and obtainable by spontaneous evaporation 

 or distillation in vacuo of the tincture. It is also precipitable by 

 tannic acid. The amount of this substance furnished by the bark, 

 is ^ per cent., according to Fllickiger and Hanbury, but some 

 observers have put it higher.f 



Angostura bark also contains a hard and a soft resin, the latter 

 coloured dark red by nitric acid. A cold aqueous solution of the 

 bark treated with ferric chloride, gives a copious reddish-brown 

 precipitate. Thin slices of the bark are not coloured by a solution 

 of ferric sulphate, consequently tannin does not appear to be 

 present. 



Medicinally, the bark is stimulant and tonic. In hot climates 

 it has been employed with success in fevers of a malignant type ; 

 the dose being from 10 to 40 grains of the powdered bark. It is 

 also used in cases of dyspepsia, dysentery, and chronic diarrhoea, 

 but in Europe it has fallen out of use, probably by reason of the 

 risk of its being adulterated with the poisonous " False bark." 



* Archiv. der Pliarm., 1858, xciii. p. 146. 



t Dr. Muter, in his " Organic Materia Medica," states the amount of this 

 substance to he li per cent. 



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