146 BESINS, BITTER PKINCIPLES, ETC. 



alcohol, but insoluble in water and petroleum spirit. It dissolves 

 in cone, suliihuric acid, from which it can be precipitated by 

 water. Betulin forms white crystals, which melt at about 200°, 

 and are not attacked by aqueous alkalies.^ 



Anacardic acid can be obtained as a Avhite crystalline mass, 

 melting at 26°, freely soluble in alcohol and ether, and dissolving 

 in cone, sulphuric acid with blood-red colouration.- 



Cardol is a colourless oil accompanying anacardic acid in the 

 cashew nut. It is soluble in alcohol and in ether, but not in 

 water, and possesses powerful vesicant properties {not shared by 

 anacardic acid). It can be removed from suspension in water by 

 agitation with chloroform. Contact with dilute potash for a short 

 time does not result in the loss of the vesicant projDerty of cardol, 

 as is the case when the alkali is concentrated and the action pro- 

 longed. The tough mass thus produced becomes red on exposure 

 to the air, and gives with basic acetate of lead a precipitate that 

 shows the same peculiarity. 



§ 156. Absinthim, etc. — The following bitter principles are also 

 soluble in ether : ahsinthiin^ (dissolves in cone, sulphuric acid with 

 brown colour, passing to violet. See also § 55), adansonin* 

 alchorn'm,^ anthemic acid,^ antirin,'^ aristolochia-yellow,^ arnicin,^ 

 asclepiadin,^^ beberic acid,^'^ cailcedrin,^^ caryophyllin^^ (coloured blood- 

 red by concentrated sulphuric acid, cf. § 55), cascariUin ^* 



^ Compare Hausmann, ' Beiträge zur Kenntniss des Betiüins,' Göttingen, 

 1878. 



- See Städeler, Annal d. Chem. und Pharm. Ixiii. 137, 1847 (Amer. Journ. 

 Pharm, xx. 139). 



^ Compare Kromayer, Archiv d. Pharm, cviii. 129, 1868. 



^ Compare Walz, Jahrb. f. prakt. Pharm, xxiv. 100, 242 ; xxvii. 1 ; 

 Wittstein, Vierteljahressch. f. prakt. Pharm, iv. 41. 



^ Compare Frenzel, Archiv d. Pharm, xxiii. 173, 1829 ; Biltz, ibid. xii. 46, 

 1826. 



6 Compare Jahresb. f. Pharm. 51, 1867 ; 46, 1871. 



' Compare Walz, Jahrb. f. prakt. Pharm, xxvii. 74, 129 (Amer. Journ. 

 Pharm, xxxv. 295). 



ä Compare Frickinger, Repert. f. Pharm. [3], vii. 12. 



9 Compare Walz, N. Jahrb. f. Pharm, xiii. 175 ; xiv. 79 ; xv. 329, 1860, 

 1861 (Amer. Journ. Pharm, xxxiii. 451). 



^^ Compare List, Annal. d. Chem. und Pharm. Ixix. 125, 1849. 



^^ Compare Maclagan, Annal. d. Chem. und Pharm, xlviii. 106, 1843 ; Iv. 

 105, 1845 (Amer. Journ. Pharm, xix. 113). 



^" Compare Caventou, N. Jahrb. f. Pharm, xvi. 335, 1861. 



" Compare Bonastre, Jahrb. f. Pharm, xi. 103 ; and Jahn, Annal. d. Chem. 

 und Pharm, xix. 333, 1837. 



'^ Compare Trommsdorf, N. Juuni. f. Pharm, xxvi. 2, 142 ; and Duval, 

 N, Jahrb. f. Pharm, viii. 95, 1857. 



