196 ODOKOGRAPHIA. 



tions made by Messrs. Schimmel* result in finding the yield of 

 essential oil to be 3'16 per cent., the sp. gr., 0-973 and boiling point 

 between 160^ and 230" C. 



Mint. 



The Menthce are herbaceous labiate plants belonging to a genus 

 whose numerous species are widely distributed over the world. 

 As general characters of the genus, the flowers occur in dense 

 whorls arranged in terminal or axillary heads or spikes. The 

 calyx is 5-toothed, usually regular ; the corolla bell-shaped, with 

 a short tube and a nearly regular 4-lobed limb, and the stamens 

 are four, erect, of equal size. Great difficulty exists in discrimin- 

 ating the species, owing to the capacity for variation possessed by 

 these plants, but the cultivated species remain constant, as the 

 plants are harvested before the seed matures, and are propagated 

 abundantly by suckers or by division of the running roots. 



The most important of the mints, commercially, are the 

 " Peppermints," which are cultivated on a large scale for the sake 

 of the volatile oil. 



Peppermint is distinguished in appearance from Spearmint 

 by its purple tint, by the leaves being stalked and by the terminal 

 spike-like inflorescence being obtuse. 



Botanically known as Mentha piperita (Lin., Spec. 805), it has 

 been frequently figured : — Bentley and Trimen, Med. Plant., t. 203; 

 Smith, Eng. Bot., t. 687; Woodville, Med. Bot, t. 169; Zorn, 

 Icones Plantarum Medicinaluui, t. 56 ; Petiver, Herbarii Britannici 

 catalogus, t. 31; Pay, Synopsis stirpium botanicarum, t. 10, f. 2^ 

 Sole, Menthoe Britannicce, t. 7. 



The occurrence of "peppermint " in England was first noticed in 

 Hertfordshire and this name w^as given to it by Pay in his 

 " Historia Plantarum," published in 1704. Its commercial history 

 dates from about the year 1750, when its cultivation was 

 commenced in a very small way at Mitcham in Surrey. Pifty 

 years later, the amount under cultivation w^as about 500 acres, and 

 the industry reached its zenith in about 1850, just one hundred 

 years after its introduction, when the area cultivated w\as about 500 



* Bericht, Oct., 1891 



