ORANGE 371 



Literature. Cultivation of Buchu Amer. Jour. Pharm., 1918, 90, 

 p. 600; Chem. and Drug, 1918, 90, p. 31. 



AURANTII DULCIS CORTEX. Sweet Orange Peel. The outer 

 layer of the rind of the fresh fruit of Citrus Aurantium sinensis (Fam. 

 Rutacese), a tree quite extensively cultivated in sub-tropical coun- 

 tries and warm-temperate regions (Fig. 164). The outer yellowish 

 layer is the part employed, and is usually removed from the fruit by 

 grating. The dried rind is an article of commerce. 



Description. The outer, orange-yellow layer recently separated 

 by grating or paring and consisting of epidermal cells, thick-walled 



FIG. 164. Citrus Aurantium, showing axillary cluster of flowers. After Berg and 



Schmidt. 



parenchyma cells of the sarcocarp, with chromo-plastids, schizo- 

 lysigenous oil cavities and globules of volatile oil; odor highly frag- 

 rant; taste pungently aromatic. 



Powder. Light brown; calcium oxalate in monoclinic prisms 

 0.020 to 0.335 mm. in diameter; walls of parenchymatous cells about 

 0.004 mm. in thickness; numerous globules of volatile oil and frag- 

 ments showing schizo-lysigenous oil cavities. 



Constituents. Resembling those of bitter orange peel, except 

 that there is but a very small quantity of the bitter principle. The 

 volatile oil which exists in large cavities beneath the 'epidermis is 

 obtained by expression from the fresh peel and is official. It con- 

 sists of about 90 per cent of d-limonene and 5 per cent of citral, 

 citronellal and the methyl ester of anthranylic acid. 



