§ 167. HESPERIDIN, ETC. 171 



acetate of lead, yellow. Zander i has recently found a glucoside 

 allied to datiscin in the seeds of Xanthium strumarium. For 

 physalin, which can easily be extracted by shaking with chloro- 

 form (§ 55), see Dessaignes and Chautard f for dulcamarin, see 

 Geissler.* The latter is soluble in acetic ether, insoluble in ether, 

 chloroform, bisulphide of carbon, and benzene. It is precipitated 

 by tannin, and by basic acetate of lead. Cone, sulphuric acid 

 dissolves it with red colouration passing to rose ; with alkalies it 

 forms reddish-brown solutions. • 



Hesperidin shows a disposition to form sphsero-crystals. It is 

 spaiingly soluble in water and cold alcohol, freely in warm 

 alcohol and acetic acid, but insoluble in ether. Ferric chloride 

 colours it brownish-red ;* cone, sulphuric acid gradually bright red 

 (limonin the same). Acetate of lead produces no precipitate. If 

 a solution in dUute potash is evaporated to dryness, the residue is 

 Coloured red, passing to violet when warmed with excess of dilute 

 sulphuric acid. Hesperidin can be recognised under the mkroscofpe 

 as spheero-crystals soluble in warm- alcohol. 



Cfdcin (polychi'oite) forms a dark red powder sparingly soluble 

 in ether and water, more easily in alcohol. Cone, sulphuric acid 

 colours it blue. Dilute acids resolve it into glucose and crocetin 

 (insoluble in water), a saffiron-like odour being developed diuring 

 the decomposition. Basic acetate of lead precipitates crocin.* 



Glya/rrhidn^ is deposited from glacial acetic acid in sphsero- 

 crystalline masses of prismatic needles. After purification with 

 acetic acid it is almost insoluble in water (forming a jelly with it), 

 but may nevertheless be extracted (in combination with bases) 

 from Uquorice-root by that menstruum. It contains nitrogen, is 

 sparingly soluble in absolute, more easily in boiling 90 per cent. 



^ ' Chem. aber die Samen von Xanthium strumarium,' Diss. Dorpat, 1880. 

 " N. EqMrt. f. Pharm. i. 216, 1851 (Amer. Joura. Pharm. xxv. 135, 136). 

 » Aichiv d. Pharm. [3], vii. 289, 1875 (Pharm. Journ. and Trans. [8],vi. 

 1010). 



* Compare Hoffmann, Ber.- d. d. chem. Ges. ix. 2S0, 685, 1876 (Journ. 

 Chem. Soc. xxx. 420, 421) ; for aurantiin, muri'ayin, limonin, ibid. ; also 

 HUger, ibid. 26 (Journ. Chem. Soc. x^ix. 709). For naringin, see Arehiv d. 

 Pharm. [3], xiv. 139, 1879. See also Dehn, Zeitschr. f. anal. Chem. ii. 103, 

 1866 ; and Tiemann und Will, Ber. d.-d. chem. Ges. xiv. 946, 1881, 



* See Weiss, Journ. f. praet. Chem. d. 65, 1868 ; Stoddart, Pharm. Journ. 

 and Trans. [3], vii. 238, 1876. 



'Compare Habermann, Annal. d. Chem. und Phann. . cxovii. 105, 1870 

 (Pharm. Journ. and Trans. [3], x. 45, 1879). Habermann changes the name 

 to glycyrrhizio acid . 



