148 RESINS, BITTER PRINCIPLES, ETC. 



spirit. Griessmayer has availed himself of this property of hoj 

 resin in the examination of beer. Cf. 55.) Other bitter prin- 

 ciples are hurin, 1 jervasic acid? jumpering liriodendrinf lycopinf 

 marrubinf mangostin, 7 masopin 8 and meconin. 9 The last-named is 

 soluble in hot water, and can be extracted fronTaqueous solution 

 after acidification with sulphuric acid, by shaking with benzene, 

 chloroform, or amylic alcohol. With benzene it can be obtained 

 fairly pure, and can be detected by cone, sulphuric acid, in which 

 it dissolves without at first producing any colouration ; but the 

 solution gradually assumes a greenish, and in the course of twenty- 

 four hours a reddish tinge. If the liquid is then warmed, the colour 

 changes to emerald-green, blue and violet, and becomes finally red. 



Meconin is accompanied in opium by meconic add, which is 

 sparingly soluble in water and ether, but more easily in alcohol. 

 Boiling with water or dilute acids decomposes meconic acid ; with 

 ferric chloride it strikes a blood-red colour, which is not discharged 

 by a little hydrochloric aci or chloride of gold. It can be 

 removed from aqueous solution by shaking with amylic alcohol. 

 Meconate of calcium is soluble, but the magnesium salt only 

 sparingly so. Chelidonic acid from Chelidonium majus is sparingly 

 soluble both in cold water and in alcohol. 10 



There may be further mentioned here, methysticin 11 (which is 

 slightly soluble in cold ether and dissolves in pure cone, sulphuric 

 acid with fine reddish-violet, in commercial with blood-red coloura- 

 tion), Jcawa'in, 12 narthecin, 13 nucin u (coloured purple by alkalies), 



1 Compare Boussingault and Rivero, Annal. de Chim. et de Phys. xxviii. 430 

 (Amer. Journ. Pharxn. ii. 346). 



2 Compare Weppen, Jahresb. f. Pharm. 31, 1872 (Journ. Chem. Soc. xxvi. 

 906). 



3 Compare Steer, Wiener Acad. Anz. B. xxi. 383. 



4 Compare Emmet, Repert. f. Pharm. Ixxv. 88 (Amer. Journ. Pharm. iii. 5). 



5 Compare Geiger, Repert. f. Pharm. xv. 11. 



6 Compare Kromayer, Archiv d. Pharm. cviii. 257, 1862. 



7 Compare W. Schmidt, Annal. d. Chem. und Pharm. xciii. 83, 1854 (. 

 Journ. Pharm. xxvii. 331). 



8 Compare Genth, Annal. d. Chem. und Pharm. xlvi. 126, 1843. 



9 Compare Pelletier, Anr-al. d. Chem. und Pharm. Ixxxvi. 190, 1853, and 

 Anderson, xcviii. 44, 1856. See also my 'Ermittel. d. Gifte,' 2nd ed., 238. 



10 See Lerch, Chem. Centralblatt, 449, 1846. 



11 Compare Nolting and Kopp, Monit. scientif. [3], iv. 920, 1874 (Pharm. 

 Journ. Trans. [3], vii. 149). 



12 Ibid. 



33 Compare Walz, N. Jahrb. f. Pharm. xiv. 345, 1861. 

 14 Compare Vogel and Reinschauer, N. Repert. f. Pharm. v. 106 (1856) ; 

 vii. 1 (1858). 



