26 



which irritate the eyes considei-ably and provoke coughing. The 

 acid dissolves in 200 pai-ts cold and in 24 parts boiling water, in 

 two parts of cold and in equal parts of boiling absolute alcohol, in 

 25 parts ether, also readily soluble in fixed and in volatile oils, and 

 without change and readily in concentrated suli)huric acid. Almost 

 all its salts dissolve in water and mostly readily so; the lead salt 

 and some other metallic salts dissolve sparingly, the salt of oxyd 

 of iron is insoluble. 



Benzoin. Exudation of the stem of Styrax Benzoin and S. 

 officinale. Yellowish or brownish, often underaiixed with white 

 almond-shaped masses, brittle, of peculiar pleasant smell and acrid, 

 balsamic taste, fuses easily while emitting vapours of benzoic 

 acid, yields to water only traces of benzoic acid, dissolves 

 readily in alcohol and in acetic acid and partly in ethei\ It 

 contains, besides 18 to 20 per cent, of benzoic acid and a little 

 volatile oil, four resins, distinguishable by the different degrees of 

 solubility. Some kinds contain also cinnamic acid. 



Berbei'ill=C4ö H17 NOs + 9H0. Discovered (1824) in the 

 bai-k of Geoffroya inermis and called Jamaicin; afterwards 

 (1826) found in the bark of Xanthoxylum Clava Herculis and 

 called Xanthopicrit ; 1835 obtained from the bark of the root of 

 Berberis vulgaris and called Berberin, but only lately recognised 

 in its true nature. Occurs, according to recent observations, also 

 in the following plants and appears to be very widely distributed : 

 in the flowers of Beiberis vulgai-is, in an Indian and Mexican 

 species of Berberis, in the bark of Xylopia polycarj^a, in the root 

 of Jateorrhiza Columbo and in the wood of Coscinium fenestra- 

 tum; in Jeffersonia diphylla, Leontice thalictroides and Podo- 

 jjhyllum peltatum; in Coptis Teeta, C. trifolia, Hydrastis 

 Canadensis and Xanthorrhiza apiifolia. — Boil the bark of the 

 root of Berberis with water, evaporate to honey-consistence, 

 treat with boiling alcohol, add one-eighth water, distil ofi" the 

 alcohol and leave the remaining liquid to stand for some 

 days in the cold. Strain the mass, hardened by fine yellow 

 needles, press and recrystallise in hot water. This product 

 being chloride of Berberin, has to be converted into the 

 sulphate, its solution mixed with solution of baryta until alkaline, 

 subjected to carbonic acid and evaporated. Draw out the B. with 

 alcohol and precipitate the solution with ether or recrystallise in 

 water. Fine, yellow needles of a pure and lasting bitter taste; 

 loses the water at 100°, fuses at 120° to a red-brown resin and de- 

 composes in higher temperatures, has a neutral reaction, dissolves 

 slowly in cold water and alcohol, readily in both when hot, not in 

 other, readily in alkalies with brown colour; forms with acids 

 crystallisable salts of mostly gold-yellow colour, neutral and 

 bitter. 



