212 THE CHEMISTEY OF ESSENTIAL OILS
peppermint oil, some of which are of very fine quality and are highly
esteemed.
The oil distilled in America and Europe is derived from varieties of
Mentha piperita, chiefly Mentha piperita, var. vulgaris or " black mint,"
and Mentha piperita, var. officinalis or " white mint ". The former ia
the hardier plant and yields the greater quantity of oil, whilst the latter
yields less oil, but of more delicate odour and flavour. The parent plant
of Japanese peppermint is Mentha arvensis, var. piperascens Holmes, or
Mentha canadensis, var. piperascens Briquet, which yields an oil much
inferior to that of Mentha piperita.
From a commercial point of view, peppermint oil appears to have
commenced its history about 1750, when cultivation was commenced at
Mitcham in Surrey. To-day the English peppermint fields are chiefly
located in this district, and in the neighbourhoods of Market-Deeping in
Lincolnshire, Hitchin in Hertfordshire, and Wisbeach in Cambridgeshire.
The oil produced by English-grown plants bears the same relation to
most of the foreign oil as is the case with lavender oil, although it i&
claimed that certain distillates of German plants approach the English
variety in fineness of odour, as they certainly do in price. Distillation
of the oil in America, which is now the most important producer of
peppermint oil, commenced in the early part of last century, when a
small distillery was erected in Wayne County, New York State. To-day
many thousand acres are under cultivation, and the principal districts
producing the oil are Wayne County (New York), various portions of
the State of Michigan, especially Wayne County (Michigan), Van Buren,
St. Joseph's and Kalamazoo Counties; St. Joseph's County, Indiana;
and to a smaller extent in some of the counties of Ohio and in some
parts of the south of the Canadian province of Ontario. The whole of the
peppermint cultivation in America is thus confined to the north-east
portion of the United States and extreme south of Canada. In Germany,
plantations have been successfully established at Miltitz, and in the neigh-
bourhood of Leipzig, by Schimmel & Co., and a fine oil is obtained from
the plants grown there. A fair amount of oil is also produced in France,
in the departments of the Yonne and du Nord. Japan and, to a certain
extent, China produce large quantities of peppermint oil. Mr. E. M.
Holmes identified the Japanese plant as Mentha arvensis, and as the
Chinese plant differs slightly from the Japanese, he retains, for the sake
of distinction, the names Mentha arvensis, var. piperascens, for the Ja-
panese, and Mentha arvensis, var. glabra, for the Chinese plant.
There appears to be some slight confusion in regard to the Japanese
peppermint plant. This plant was brought over to England by the late
Mr. Thomas Christy, and this plant was considered by Mons. Malui-
vaud, the French authority on mints, to be a variety of Mentha arvensis,
and in this Mr. E. M. Holmes acquiesced, and it was named Mentha
arvensis, var. piperascens Holmes. Dr. Thorns has recently carried out
some cultivation experiments at Dahlem, near Berlin (which will be re-
ferred to later), with plants received from Japan and examined by Dr.
Briquet, the German authority on mints, who considered it to be a
variety of Mentha canadensis, and he named it Mentha canadensis, var.
piperascens Briquet, but stated that in his opinion it was identical with
Christy's plant. This was probably a misunderstanding arising from his
not having seen the particular plant grown by Christy, for as grown at
Sydenham, and also by Holmes at Sevenoaks, it showed a very decided
difference.