- 101 — 



respect to pure peppermint-aroma. So far no reports are available con- 

 cerning the condition of the peppermint-plantations in England. 



Peppermint Oil, French. The cultivated species of Mentha, and in 

 particular Mentha piperita, have been examined botanically by A. and 

 E.G.Camus 1 ). Mentha piperita does not constitute a separate species, but 

 is a hybrid of Mentha viridis and Mentha aquatica. It may be regarded as 

 a sterile plant, as it fruits rarely, and even then the fruit is mostly badly- 

 developed, hence the plant must be propagated by sub-dividing the rhizomes. 

 Like all Mentha-species, Mentha piperita is extraordinarily variable. To add 

 to the confusion, different varieties are cultivated in various plantations 

 under the common denomination of "peppermint". Several varieties also 





Ordinary ] 



Peppermint 



Red Peppermint 



diso 



0,9191 



0,9184 



0,9170 



0,9136 







« D 



— 10° 54' 



— 8°2 f 



— 16°38' 



— 13° 44' 







Solubility in 80% alcohol . . . 



1 vol. 



afterwards 

 clouding 



— 



1 vol. 



afterwards 

 clouding 



— 



Acid v 



0,8 



0,8 



1,0 



1,2 



Ester v 



40,5 



31,7 



18,9 



17,5 



Menthyl acetate 



14,3°/o 



11,2% 



6,7% 



6,2% 



Ester v. after acet 



160,8 



169,1 



180,2 



185,6 







Total Menthol 



50,9% 



53,9 °/o 



58,0% 



60,0% 



Free Menthol 



39,6% 



45,1% 



52,8% 



55,1% 







Proportion of Menthone ..... 



7,3% 



— 



16,8% 



— 



occur of the original species. Mentha piperita embraces two groups; group I 

 including the subspecies piperita, Briq. with numerous varieties, while 

 group II includes the sub-species citrata, Briq., which under the name of 

 "citronelle" is much grown in France because of its pleasant aroma, but 

 which does not appear to be used commercially. In its internal structure 

 Mentha piperita exhibits certain features midway between those of Mentha 

 viridis and Mentha aquatica. How variable are the Mentha-species is 

 Jfcown by Mentha viridis, L. and Mentha aquatica, L.; for the authors 

 describe no fewer than six varieties of the former, and as many as eight 

 of the 'latter, besides indicating many others. 



As a complement to their botanical review the authors give the analy- 

 tical peculiarities of the essential oils from the ordinary and from the 



*) Berichte von Roure-Bertrand Fils, October 1911, 3. 



