OLEUM LIMONIS 271 



283. LIMONIS CORTEX THE RIND. LEMON PEEL. The undried 

 outer rind of the ripe fruit of Citrus medica Linne (C. limonum Risso, 

 U.S. P. IX), removed by grating. The fruit comes from the Medi- 

 terranean and tropical regions (see Orange). The outer surface is of 

 a light yellow color and ruggedly glandular from the oil-cells; odor 

 fragrant; taste aromatic and bitterish. 



Microscopically, the rind of the lemon resembles that of the orange. 

 Powder. Microscopical elements of: See Part iv, Chap. I, B. 



CONSTITUENTS. A pale yellow volatile oil (sp. gr. 0.87) consisting mainly 

 of hydrocarbons, citrene (Ci Hi 6 ), cymene (CioHn), also citral 

 (CioHieO), and a compound ether. Hesperidin (C 2 2H 26 Oi2), a bitter 

 principle, produces with ferric salts a black color. 

 Used as a flavoring agent. 



OFFICIAL PREPARATION. 



Tinctura Limonis Corticis (50 per cent.). 



284. OLEUM LIMONIS. OIL OF LEMON PEEL, OR RIND. A volatile 

 oil obtained by expression from the fresh lemon peel. It is a pale 

 yellow, limpid liquid, having a lemon 



taste and a fragrant odor. . It should 

 be protected from light in well-stoppered 

 bottles. Oil of citral, used in perfum- 

 ery, is obtained from Cit'rus med'ica 

 Risso, a large oblong fruit with rough 

 surface known in England as the 

 citron. 



Oil of lemon consists of two isomeric 

 oils', chiefly citrene or limonine, CioHie, 



.., I / i i i i \ FIG. 153. Cross-section of Lemon 



with citral (an aldehyde) and a crys- fruit. 



talline product which fuses at 143 to 



i44C. (289 to 29iF.), colored yellow by H 2 SO 4 , and green by 

 HNO 3 . Used principally as a flavor assayed by the official process 

 not less than 4 per cent, of the aldehydes from oil of lemon calcu- 

 lated as citral. 



ADULTERATION OF THE OIL OF LEMON. It is adulterated with the volatile 

 oil of other fruits of the genus Citrus. These are difficult to detect; 

 odor and taste must be chiefly relied upon. 



OFFICIAL PREPARATIONS-. 



Spiritus Aurantii Compositus (5 per cent.). 



Spiritus Amonniae Aromaticus, Dose: 30 ITJ (2 mils). 



285. OLEUM BERGAMOTTJE. OIL OF BERGAMOT. A volatile oil obtained 

 by expression from the rind of the fresh fruit of Cit'rus berga'mia Risso et 

 Poiteau, the fruit being collected in November or December, still greenish, 



