484 



LABIATiE. 



if shaken with a concentrated solution of bisulphiite of sodium. It is 

 ■worthy of note that oils of different origin, which cannot be distin- 

 guislied by means of nitric acid, exhibit totally different colorations if 

 mixed with either of the liquids just named, or with vapour of bromine. 

 This beliaviour may be of some use in the examination of comuiercial 

 sorts of peppermint oil. 



As to bisulphite of sodium, it yields a solid compound with certain 

 kinds of peppermint oil, which we have not yet examined, 



~ " " " ~omm 



In several parts of Europe, as well 



as in the United States, peppermint is cultivated on the large scale as a 

 medicinal plant. 



In England the culture is carried on in the neighbourhood of Mitchara 

 in Surrey, near Wisebeach in Cambridgeshire, Market Deeping in Lin- 

 colnshire, and Hitchin in Hertfordshire. 



At Mitcham in 1850 there were about 500 acres under cultivation; 

 in 18G4 only about 219 acres.^ At Market Deeping there were in 1871 

 about 150 acres cropped with peppermint. The usual produce in oil may 

 be reckoned at 8 to 12 lb. per acre. The fields of peppermint at Mitcliam 

 are level, with a rich, friable soil, well manured and naturally retentive 

 of moisture. The ground is kept free from weeds, and in other respects 

 is carefully tilled. The crop is cut in August, and the herb is usually 

 allowed to dry on the ground before it is consigned to the stills. These 

 are of large size, holding 1000 to 2000 gallons, and heated by coal; 

 eacli still is furnished with a condensing worm of the usual character, 

 which passes out into a small iron cage secured by a padlock, in which 

 stands the oil separator. The distillation is conducted at the lowest 

 possible temperature. The water that comes over with the oil is not 

 distilled with another lot of herb, but is for the most part allowed to 

 run away, a very little only being reserved as a perquisite of the work- 

 men. _ The produce is very variable, and no facilities exist for estimat- 

 ino- it with fipr^iirnn^r 2 T* ,'« iw.„.„,, „i„j.„j +T,„i « f/^n nf dried 



— o * accuracy,^ It is however stated that a ton of dr— - 



peppermint yields from 2| to 3^ pounds of oil, which equals Oil to Ob 

 per cent. But we have been assured by a grower at Mitcham that the 

 yield is as much as (i pounds from a ton, or 0-2G per cent. 



At Mitcham and its neighbourhood two varieties of peppermint are 



Black Mint, but the differences between the two are very slight. The 

 Black Mint has ^mrp^e stems ; the White Mint, green stems, and as we 

 have observed, leaves rather more coarsely serrated than those of the 

 Black. The Black Mint is more prolific in essential oil than the White, 

 and hence more generally cultivated ; but the oil of the latter is superior 

 m_ dehcacy of odour and commands a higher price. White Mint is 

 said to be principally grown for drying in bundles, or as it is terniea 



hunching. 



Peppermint is grown on a vastly larger scale in America, the 

 Where the cultivation is carried on beinjr Southern Michigan, 



•ica. the localities 



Western 



wSt^- o?"""- ^- (1851)297. m ; also 

 \\arren m Pharm. Journ. vi. (1865) 257. 

 io these papers and to personal iiiqni rie.s 



SafinJf ^'^'"'^ for most of the partLlars 



"off '" P^PP^™^"it culture at Mitcham. 



fuJy the larger growers have stills. 



ho 



These they let to smaller cultivators v, ^ 

 pay so much for distilling ^f^'^^,, 

 whatever the still can he made to co ^ j,,^ 

 without reference to weight. O-^ ^^ 

 dried herb is preferred to tfe ^r^^^' j^„,, 

 larger quantity can be distilled at one 



