HERBA MENTH/E PIPERITA. 481 



Chemical Composition— Spearmint yields an essential oil {Oleum 

 MentJue viridis) in which reside the medicinal virtues of the plant. 

 Kane/^who examined it, gives its sp. gr. as 0-914, and its boiling point 

 as 160" C. The oil yielded him a considerable amount of stearoptene. 

 Gladstone 2 found spearmint oil to contain a hydrocarbon almost 

 identical with oil of turpentine in odour and other physical properties, 

 mixed with an oxidized oil to which is due the peculiar smell of the 

 plant. The latter oil boils at 225° C. ; its sp. gr. is Odol, and it was 

 lound to be isomeric with car vol, C^'^ff'O. According to our experi- 

 ments the oil, distilled from Curled ]Mint grown in Germany, deviates 

 the plane of polarization 37°"4 to the left when examined in a column of 

 100 millimetres. We prepared from it the crystallized compound 

 (C ^ff ^0)^^SH2, and isolated from it the liquid Ci«H''0, which differs from 

 carvol (see Fructus Carui, page 30G) by its levogyrate power.' 



Uses — Spearmint is used in the form of essential oil and distilled 

 water, precisely in the same manner as peppermint. In the United 

 otates the oil is also employed by confectioners and the manufacturers 

 of perfumed soap. 



Substitutes — Oil of spearmint is now rarely distilled in England, 

 its high cost^ causing it to be nearly unsaleable. The cheaper foreign 

 t^l is offered in price-currents as of two kinds, namely American and 

 (^erman. ^ Of the first we have already spoken : the second, termed in 

 ^erman Krauseminzdl,is the produce of Mentha aquatica L. var. y cri.^/Ht. 

 bentham, a plant cultivated in Northern Germany. Its oil seems to 

 agree with the oil of spearmint. 



HERBA MENTHiE PIPERIT/E. 



Peppemihit; F. Mentlie poiiree ; G. Pfcfferminze. 



Botanical O rigin—3Ienth a piperita Hudson (non Linn.), an erect 

 usually glabrous perennial, much resembling the Common Spearmint oi 

 the gardens, but differing from it in having the leaves all stalked the 

 flowers larger, the upper^whorls of flowers somewhat crowded togetlier, 

 and the lower separate. In the opinion of Bentham it is possibly a mere 

 yariety of M. hirsuta L., with which it can be connected by numerous 

 intermediate forms. 



. Peppermint rapidly propagates itself by runners, and is now lound 

 in ^vet places in several parts of England, as well as on the Contmcnt 

 it is cultivated on the laroe scale in England, France, Germany, and 

 ^N orth America. 



History—Mentha piperita was first observed in Hertfordshire b^' 

 ^i'- Eales, and communicated to Kay, who in the second edition ot his 

 fjnopsi8 Stlrpium BHtanmcarum, 1696, noticed it under the name o 



Menth 

 fervid 



foil is Mentha/ 



}frntha 2'>ahitit r'l .'i 



\l;^nlosoplncal Magazine, xiii. (18.'18)444. ^rrice from 18-24 to 18:^0, 40.. to 4S.. 



,^^^ourn of Chnnlca^ Society, ii. (1854) per Ib.^^^^^^ ... ^^.^^^ ^^^^ 



■ FiUckiger, Phurm.Jmrn. vii. (187(i) 75. 



2 H 



