148 RESINS, BITTER PRINCIPLES, ETC. 



spirit. Griessmayer has availed himself of this property of hojj- 

 resin in the exarninatioJiof beer. Cf. §55.) Othey Isitter prin- 

 ciples are hurin,^ jervasic acid," junijpmn,^ liriodendrin,^ lycopin,'^' 

 marr'ubm,^ mangoshn,'' masopin^ knd meconin.^ The last-nained is 

 soluble in hot water, 'and can be extracted from aqueous solution 

 after acidification with sulphviric- 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 gi-adually assumes a*gi-eenisji, and in the course of twenty- 

 four hours a re<idi^ tinge. If the liquid is then warmed,' the colour 

 •iiauges to 6merald-green, blue and violet,, and becomes finally red. 



Meconin is accompanied in opium, by meconic acid, which ie 

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

 Boiling with water or-dilute acids decomposes meeonic acid ; with 

 ferric chloride it strikes a blood-red colour, which is riot 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. Chelidomc acid froni Chelidonium majus is sparingly 

 soluble both-m cold water and in alcohol.^' 



There may bo further mentioned here,, methjsticin'"- (which is 

 ^lightly, soluble in cold ether and dissolves in^Mre.conc. sulphuric 

 aoid'with fine rpddish-violet, in coifimercialvri^ blood-red coloura- 

 tion), kawdm,'^'^ nartJiccin,^^ nucin^^ (coloured purple by alkalies), 



^ Compare Boussinij-aultandKivero, AnnaL deChim. et dePhys. xxviii. 430 

 (Amer. Journ. Pharm. ii. 346)1 



'^ Compare Weppen, Jahresb. f. Pharm. 31, 1872 (Jonin. Chem. Soc. xxvi, 

 906). 



^ Compare Steer, Wiener Acad. A'nz. B. xxi. 383,. 



'' Compare Emmet, Kepert. f. Pharm. Ixxv. 88 (Amer. Journ. Pharm. iii. a). 



* Compare Geiger, Repert. f. Phai-ra. xv. 11. 



"• Compare .Kromayer, Archiv d. Pharm. cviii. 257, 1862. 



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

 Journ. Pharm. xxvii. 331). 



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



' Compare Peiletier, Annal. d.. Chem. und Pharm. Ixxxvi. :|90, 186?, and 

 Anderson, xcviii. 44, 1856. ^ee also my 'Ermittel. d. Gjfte,' 2nd ed., 238. 



w See Jierch; Chem. Centralblatt^ 449, 1846. 



" Compare Noltiag and Kopp, Monit. scientif. "[3], iv. 920, 1874 (Pharm. 

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



la Ibi^. 



" Compare Walz, N. J^ahrb. f. Pharra. xiv. 345, 1S61. 



" Compare Vogel and' Reinsohauer, N. BepciCt. I. Pharm.. v. 106 (1856) ; 

 vi--. 1 (1858).. 



