592 BOTANY AND PHARMACOGNOSY. 



Constituents. — Volatile oil; a very small quantity of hesr 

 peridin and other bitter principles (see bitter orange peel) ; a 

 principle resembling tannin ; calcium . oxalate ; ash about 4 per 

 cent. The volatile oil obtained by expression from fresh lemon 

 peel consists of 90 per cent, d-limonene; 7 to 10 per cent, of citral, 

 which is the most important constituent; and a small quantity 

 of citronellal, geranyl acetate, pinene, terpineol, methyl heptenone, 

 a sesquiterpene and octyl and nonyl aldehydes. 



AURANTII AMARI CORTEX.— BITTER ORANGE 

 PEEL. — The rind of the unripe fruit of Citrus Aurantmm amara 

 (Fam. Rutaceae), a tree (Fig. 158) indigenous to Northern 

 India and cultivated in the Mediterranean region, the West Indies 

 and the States bordering on the Gulf of Mexico (p. 306). The 

 fruit is collected before it is ripe, the rind removed and used either 

 in, the fresh or dried condition. The commercial article is 

 obtained from Malta, Sicily and Spain. 



Description. — Usually cut longitudinally into quarters ; ellip- 

 tical, acute at both ends, 4 to 6 cm. long, 2 to 3 cm. wide, 2 to 6 

 mm. thick ; externally yellowish or brownish-green, with numer- 

 ous circular depressions, a scar at one end and occasionally the 

 remains of the calyx ; internally light yellowish-brown, wrinkled, 

 with numerous conical projections and numerous large oil-secre- 

 tion reservoirs ; fracture short, tough, surface porous ; odor aro- 

 .matic; taste aromatic and bitter. 



Occasionally in ribbon-like bands 2 to 12 cm. long, 5 to 10 

 mm. wide, about 2 mm. thick; externally yellowish-broWn. 



Constituents. — Volatile oil, resembling that of sweet orange 

 peel but with a superior flavor and a bitter taste; several bitter 

 principles: (a) aurantiamarin (1.5 to 2.5 per cent.), an amor- 

 phous, bitter glucoside, to which the bitter taste is chiefly due; 

 (b) aurantiamaric acid (o.i per cent.), a very bitterj green, 

 amorphous, resinous principle; (c) naringin (aurantii'n)-, a 

 yellowish, . crystalline, bitter glucoside; (d) isohespeiSidin (0.4 

 to 3 per cent.), a slightly bitter glucoside. The drug also con- 

 tains 5 to 8 per cent, of a white, crystalline, tasteless glucoside 

 Hesperidin, which separates in sphere-crystals on placing the 

 •fresh fruit in alcohol. Hesperidin is colored reddish-brown 'with. 

 ferric chloride and on' hydrolysis yields a sweet principle hespere- 



