203 MENTHA PIPERITA 



and dried state has a peculiar, aromatic, and agreeable odour, and 

 an aromatic, warm, burning, bitterish taste, followed by a sensa- 

 tion of coolness when air is drawn into the mouth. The proper- 

 ties of the herb depend essentially upon the official oil of pepper- 

 mint. This oil is colourless, pale yellow, or greenish when 

 recent, but like the oil of spearmint it becomes reddish by age. 

 Its sp. gr. varies from 0*84 to 0'92. It has a powerful pene- 

 trating aromatic taste, like that of the herb, followed by a sensa- 

 tion of cold, and a strong agreeable odour. Oil of peppermint 

 consists of two substances, one fluid, the other solid ; the 

 chemical nature of the former has not been determined; the 

 latter, which is sometimes deposited from oil of peppermint, when 

 it is subjected to a cold of about 8 below the zero of Fahrenheit, 

 in the form of colourless hexagonal crystals, is called menthol or 

 peppermint camphor. Its proportion varies much in different 

 oils. The so-called Chinese oil of peppermint of commerce is 

 distilled at Canton from Mentha javanica, Bl. It is pure crystal- 

 lised menthol. Oil of peppermint upon long standing also deposits 

 a solid crystalline portion, which is commonly termed the Stea- 

 roptene of oil of peppermint. 



Medical Properties and Uses. Peppermint is the most agree- 

 able and powerful of all the mints. It possesses aromatic, 

 carminative, stimulant, antispasmodic, and stomachic properties. 

 These qualities are especially possessed by the official oil, which is 

 employed in medicine in flatulence, nausea, flatulent colic of 

 children, spasmodic affections of the stomach and bowels, and is a 

 frequent addition to other medicines to cover their unpleasant 

 taste. It is also extensively employed for flavouring cordials and 

 sweetmeats. 



Per. Mat. Med., by B. and R., p. 283; Pharmacographia, p. 434 ; 

 U. S. Disp., by W. and B., pp. 559 and 1309 ; Per. Mat. Med., 

 vol. ii, part 1, p. 512; Ph. Jl., Feb. 25, 1871, p. 682, and Oct. 

 14, 1871, p. 321. 



DESCRIPTION OF PLATE. 



Drawn from a plant grown in the garden of the Royal Botanic Soc., London. 



1. A flower. 



2. Corolla cut open. 



3. Vertical section of calyx and ovary (1 3 enlarged.). 



