Transcriber’s Note
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U. S. DEPARTMENT OF AGRICULTURE.
BUREAU OF PLANT INDUSTRY—BULLETIN NO. 90, PART III.
B. T. GALLOWAY, _Chief of Bureau_.
PEPPERMINT.
BY
ALICE HENKEL,
ASSISTANT, DRUG-PLANT INVESTIGATIONS.
ISSUED DECEMBER 28, 1905.
[Illustration]
WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1905.
CONTENTS.
Page.
Description 5
Countries where grown 6
Peppermint cultivation in the United States 7
Cultivation 8
Conditions injurious to crop 9
Harvesting and distillation 10
Description of still 11
Peppermint oil and menthol 12
Export of peppermint oil 13
Prices of peppermint oil 14
ILLUSTRATIONS.
Page.
FIG. 1. Peppermint “runners,” showing method of propagation 6
2. Leaves and flowering top of peppermint 6
3. Peppermint still (after Dewey, in Bailey’s Cyclopedia of
American Horticulture) 12
B. P. I—189.
PEPPERMINT.[1]
DESCRIPTION.
One of the most important essential oils produced in the United States
is distilled from the peppermint plant and its varieties. The three
kinds of mint grown in this country for the distillation of peppermint
oil are the so-called American mint (_Mentha piperita_ L.), the black
mint (_Mentha piperita vulgaris_ Sole), and the white mint (_Mentha
piperita officinalis_ Sole), the two last named being varieties of the
American mint.
The American mint, although introduced from England many years ago,
is so called from the fact that it has long been cultivated in this
country, and the name “State mint” has been applied to it in the State
of New York for the same reason.
The peppermint, or American mint, is now naturalized in many parts of
the eastern United States, occurring in wet soil from the New England
States to Minnesota, south to Florida and Tennessee. It is an aromatic
perennial belonging to the mint family (Menthaceæ), and propagates by
means of its long, running roots (fig. 1). The smooth, square stems are
erect and branching, from 1 to 3 feet in height, bearing dark-green,
lance-shaped leaves, which are from 1 to 2 inches long, and from
one-half to 1 inch wide. The leaves are pointed at the apex, rounded or
narrowed at the base, sharply toothed, smooth on both sides, or with
hairy veins on the lower surface. The flowers are borne in whorls in
dense, terminal spikes; they are purplish, with a tubular, five-toothed
calyx, and a four-lobed corolla. (Fig. 2.)
[Illustration: FIG. 1.—Peppermint “runners,” showing method of
propagation.]
The two varieties mentioned are closely related botanically, although
in general appearance they are quite different. The variety known as
black mint (_Mentha piperita vulgaris_) has purple stems and slightly
toothed, dark-green leaves, while the white mint (_Mentha piperita
officinalis_) has green stems, with brighter green leaves, which are
more lance-shaped and more deeply toothed. Black mint is much more
hardy and productive than either the American mint or the white mint,
and is grown on nearly all peppermint farms in this country. The
white mint, which produces a fine grade of oil, is rarely cultivated
on a commercial scale in this country on account of its inability to
withstand the climate and its smaller yield of essential oil.
The oils spoken of as Japanese and Chinese “peppermint” oils are
not obtained from the true peppermint plant, but are distilled from
entirely different species, namely, _Mentha arvensis piperascens_
Malinvaud and _Mentha arvensis glabrata_ Holmes, respectively.
COUNTRIES WHERE GROWN.
The most important peppermint-producing countries are the United
States, England, and Japan. Peppermint is grown on a smaller scale in
Germany, France, Italy, Russia, China, and southern India.
[Illustration: FIG. 2.—Leaves and flowering top of peppermint.]
In Japan, peppermint cultivation is said to have been undertaken
before the Christian era. The plant grown there is not, as already
stated, the peppermint cultivated in our country, but _Mentha arvensis
piperascens_, which is entirely distinct from the true peppermint, not
only botanically but also in taste and odor.
Peppermint is cultivated on many drug farms in England, especially at
Mitcham, the middle of the eighteenth century marking the beginning of
peppermint cultivation in that country. Up to 1805, however, there were
no stills at Mitcham, and the crops obtained there were sent to London
for distillation. About 1850, at which time the peppermint industry in
England was at its height, the effect of American competition began to
be felt, and caused a decided check in the production.
FOOTNOTES:
[1] In response to a steady demand for information relating to the
peppermint industry, Miss Alice Henkel, Assistant in Drug-Plant
Investigations, has been requested to bring together the most important
facts regarding the history, culture, and utilization of the peppermint
plant. The information here presented has been obtained in large part
from scattered articles on the subject, and in part from experience
with the plant in the Testing Gardens of the Department of Agriculture.
RODNEY H. TRUE, _Physiologist in Charge_.
OFFICE OF DRUG-PLANT INVESTIGATIONS.
_Washington, D. C., October 14, 1905._
PEPPERMINT CULTIVATION IN THE UNITED STATES.
Wayne County, N. Y., in 1816, was the first locality in this country
to distill peppermint on a commercial scale. The supply of rootstocks
was obtained from the wild plants found growing along the banks of
streams and brooks. Adjacent counties soon undertook the cultivation
of peppermint, but Wayne County was then, and is now, the principal
peppermint district in New York.
The cultivation of peppermint was extended to Ashtabula, Geauga, and
Cuyahoga counties in Ohio, and also to northern Indiana. Roots were
taken from Ohio into St. Joseph County, Mich., the first plantation
being made on Pigeon prairie in 1835. Other plantations in St.
Joseph County were established the following years, and adjoining
counties soon took up the cultivation of peppermint, and southwestern
Michigan has been for thirty-five years or more the greatest
peppermint-producing section in the United States.
About 1844 an interesting peppermint oil monopoly[2] was undertaken
by a New York firm, which seems to have put an end to peppermint
cultivation in Ohio, for none of the counties just mentioned has since
been heard from as a peppermint-producing section.
The first step taken by this New York firm in its efforts to control
the peppermint oil market was to send a representative to Liverpool,
England, to ascertain the amount annually demanded by that market,
which was found to be about 12,000 pounds. This done, another agent
was sent West to determine the amount produced annually, with the
result that it was found that the farms in New York did not produce
enough oil for their purposes, the plantations in Ohio too much, while
those in Michigan seemed to produce just about the right amount to
satisfy the Liverpool demand. A contract was then entered into by
this agent with the producers in New York and Ohio “whereby he bound
them under heavy penalties to plow up their mint fields and destroy
the roots, and not plant any more mint, or sell or give away any
roots, or produce or sell any mint oil for the period of five years.”
For this wholesale destruction of their mint fields the producers
received a bonus of $1.50 per acre. Next a contract was made by the
agent with the producers of St. Joseph County, Mich., agreeing to pay
them $2.50 a pound for their mint oil, every ounce of the mint oil to
be delivered for a period of five years to the agents named in the
contract. They also were prohibited during this period from extending
their plantations and from selling roots to anyone. The producers held
to these contracts for about three years, after which period the New
York firm was not so anxious to enforce them, having, in the meantime,
acquired a large fortune through its peppermint oil monopoly.
Since that period the area devoted to peppermint cultivation in
Michigan has steadily increased, and northern Indiana, with its
principal centers of production in St. Joseph, Steuben, and La Grange
counties, continues to place on the market a considerable quantity of
oil. Ohio seems to have abandoned peppermint cultivation, at least on
a commercial scale, and New York, for a number of years and until very
recently, had greatly reduced the area under peppermint, thousands of
acres formerly devoted to this crop having been given over to sugar
beets, onions, and celery. In 1889 Wayne County, N. Y., had 3,325 acres
of peppermint, whereas in 1899 there were only 300 acres. In 1905,
about 933 acres were under cultivation.
Special canvassers appointed by the State of Michigan[3] made a canvass
of 299 growers in the peppermint district in that State, covering 39
townships in nine counties (Allegan, Berrien, Branch, Cass, Kalamazoo,
Oakland, St. Joseph, St. Clair, and Van Buren), and the total number
of acres under peppermint cultivation, the number of pounds of oil
distilled, and the average number of pounds per acre, as ascertained by
this canvass, for the years 1900, 1901, and 1902, are as follows:
——————————————————————————————————+——————————+——————————+—————————
Items. | 1900. | 1901. | 1902.
——————————————————————————————————+——————————+——————————+—————————
Total number of acres grown | 2,112 | 2,782½ | 6,400⅔
Total number of pounds distilled | 47,628½ | 63,718¾ | 82,420¼
Average number of pounds per acre | 22.5 | 23.9 | 12.8
——————————————————————————————————+——————————+——————————+—————————
FOOTNOTES:
[2] Proc. Amer. Pharm. Assoc., 7: 449-459 (1858).
[3] Twentieth Annual Report of the Bureau of Labor of the State of
Michigan, 1903, pp. 438-447.
CULTIVATION.
Peppermint cultivation is most profitable on muck lands, such as
are now used in Michigan for this crop and for celery and cranberry
culture. These muck lands were formerly marshes and swamps, which
have been reclaimed by draining, plowing, and cultivating, the swamp
vegetation having been thus subdued, and the decayed vegetable matter
resulting in a very black soil which is most admirably adapted to mint
cultivation. Formerly peppermint was grown exclusively on upland soil
in Michigan, but it is a very exhausting crop on such land. Only two
crops can be obtained from upland plantations, and after the second
year’s harvest the land is plowed and a rotation of clover, corn, etc.,
is practiced for five years before peppermint is again planted. But on
the rich muck land peppermint can be grown year after year for six or
seven years, the land being plowed up after each crop is harvested, and
the runners turned under to form a new growth the succeeding year. The
ground is harrowed in autumn and again in spring, and carefully weeded.
Peppermint will grow, however, on any land that will produce good crops
of corn, the ground being prepared by deep plowing and harrowing.
In Michigan[4] the land is plowed in the autumn, and early in spring
it is harrowed and marked with furrows about 3 feet apart. The roots
selected for planting are from one-eighth to one-quarter of an inch
thick, and from 1 to 3 feet long; and the workmen engaged in “setting
mint,” as the process is called, carry these roots in sacks across
their shoulders and place them in the furrows by hand, covering the
roots with one foot and stepping on them with the other. The roots are
planted so close together in the furrow as to form a continuous line.
An expert workman can plant about an acre in a day.
In about two weeks the young plants will make their appearance, and are
carefully hoed and cultivated until July and August, when the plants
have usually sent out so many runners as to make further cultivation
difficult. The crop is cultivated with horse cultivators, but if the
land was very weedy in the first place, the weeds will have to be
pulled by hand. It is very necessary that the land be free from weeds,
as any collected with the peppermint crop will seriously injure the
quality of the oil.
It may be interesting to note here that on muck lands, when necessary,
the horses are usually provided with mud shoes to prevent their sinking
into the soft, wet ground, these mud shoes consisting of wide pieces of
iron or wood about 9 by 10 inches, fastened to the hoofs and ordinary
shoes by means of bolts and straps.
CONDITIONS INJURIOUS TO CROP.
Cold and wet weather or extremely dry periods have a very unfavorable
effect on the mint crop. Insect enemies also tend to cut down the
mint harvest—grasshoppers, crickets, and cutworms sometimes doing
considerable damage. A rust, causing the foliage to drop off and
leaving the stems almost bare, is apt to follow if very moist weather
occurs toward the latter part of the season. Weeds are especially to
be avoided in a mint field, since, as stated, the quality of the oil
will be seriously impaired if these are harvested with the peppermint.
The weeds generally found in a peppermint field are Canada fleabane
(_Leptilon canadense_), fireweed (_Erechtites hieracifolia_), giant
ragweed (_Ambrosia trifida_), pennyroyal (_Hedeoma pulegioides_),
Eaton’s grass (_Eatonia pennsylvanica_), June grass (_Poa pratensis_),
and other low grasses.
FOOTNOTES:
[4] Twentieth Annual Report of the Bureau of Labor of the State of
Michigan, 1903, pp. 438-447.
HARVESTING AND DISTILLATION.
The first crop of mint is harvested in the latter part of August, when
the plants are in full flower, and the gathering continues until about
the middle of September, the stills running night and day until all
the mint is disposed of. The first crop is usually cut with a scythe,
as mowing machines do not work well on soft cultivated land. The
succeeding crops are cut with a mowing machine or sweep-rake reaper.
The highest yield per acre and the best quality of oil are obtained
from the first year’s crop. Sometimes, if the weather conditions have
been very favorable, a second cutting is made. The yield of oil from
peppermint obtained from the same field sometimes varies very much, the
condition of the atmosphere seeming to exert an influence upon it, as
it is said that mint cut after a warm and humid night will yield more
oil than that cut after a cool and dry night. It requires about 330
pounds of dried peppermint to produce 1 pound of oil, and the yield of
oil from an acre ranges from 12 to 50 pounds.
If the mint crop has been grown on muck land, all that is necessary
after the crop has been harvested is to plow up the land and turn the
runners under for a new crop. If grown on upland, after the second
year’s crop is in, or, at the most, after the third year’s harvest, the
land is plowed and then given up to other crops. Peppermint exhausts
the land, and it is necessary to practice rotation of crops for about
five years in order to put the land in condition if it is desired to
use it again for peppermint cultivation.
After the plants are cut they are usually placed in windrows until they
are dried, but are not allowed to become so dry as to permit the leaves
to shatter off, and are then taken to the distillery. Some growers
believe that if the plants are allowed to dry there will be a smaller
oil content owing to the escape of some of the oil into the atmosphere,
and so have the plants brought to the distillery in the green state;
but Mr. A. M. Todd[5] is of the opinion that no loss of oil will
result from drying, his experiments along this line showing that the
dry plants can be distilled three times as rapidly as the green plants,
and that a larger quantity of oil may be obtained. He states that—
To obtain the best results, both as to quality of essential oil and
economy of transportation and distillation, the plants should be dried
as thoroughly as possible without endangering the loss of the leaves
in handling. Distillation should then take place as soon as convenient
to prevent the oxidation of the oil in the leaf by atmospheric action.
The smaller producers, who have no stills of their own, have their mint
crop hauled to the nearest peppermint distillery, where it is distilled
for them at a cost of 25 cents per pound of oil.
FOOTNOTES:
[5] Amer. Jour. Pharm., 60: 328-332 (1888).
DESCRIPTION OF STILL.
The apparatus used in peppermint distillation in the early years of the
industry in this country consisted of a copper kettle, from the top
of which a pipe connected with a condensing “worm.” Water was placed
in the kettle and the plants were immersed in it, and direct heat was
applied to the bottom from a furnace. With such a still only about 15
pounds of oil could be obtained from a charge. In 1846, large wooden
vats were substituted for the copper kettles, and the plants were
distilled by steam passing through them. The kettle formerly used as
the still was now employed to generate steam, a long pipe conveying the
steam to the bottom of the vats. With this method of distillation from
75 to 100 pounds of oil could be obtained from a charge without much
additional expense.
A modern peppermint still (fig. 3) may be briefly described as follows:
The apparatus required consists of a boiler, a pair of large circular
wooden vats, a condenser, and a receiver. The boiler, of course, is
used for the generation of steam.
Two wooden vats are used in order that they may be filled and emptied
alternately. These vats are about 6 feet high and about 5 feet in
diameter, with tight-fitting removable covers and perforated false
bottoms. Steam pipes are led from the boiler into the bottom of the
vats.
The condenser consists of a series of pipes of block tin, either
immersed in tanks of cold water or over which cold water is kept
running, the condenser being connected with the top of the distilling
vats. The condensed steam, together with the oil, flows into a metallic
receiver, in which the oil, being lighter than the water, rises to the
top and can be drawn off.
The perforated false bottoms with which the vats are supplied permit
the passage of steam. A strong iron hoop is placed about this false
bottom, and two pairs of stout chains, which meet at the top of the
vat in a pair of rings, are attached to it. After the charge has been
distilled it is drawn from the vats by means of this arrangement.
The plants are thrown into the vats and are closely packed by two or
three men tramping upon them, and as the vat becomes about one-third
full the packing is still further assisted by turning in a small supply
of steam, which softens the plants. When the vat is filled the tight
cover is replaced and a full head of steam turned on. In the largest
distilleries the vats have a capacity of from 2,000 to 3,000 pounds of
dried plants each.
[Illustration: FIG. 3.—Peppermint still. (After Dewey, in Bailey’s
Cyclopedia of American Horticulture.)
_A_, boiler; _B_, steam pipes leading to vats; _C_, valves for shutting
off steam; _D_, mint packed in vat ready for distilling; _E_, mint
being lowered into vat; _F_, tight-fitting cover used alternately for
both vats; _G_, pipe from top of vat, joined at _H_ so as to swing
to other vat; _J_, perforated pipe, from which cold water drops over
condensing tubes; _K_, supply pipe for cold water; _M_, condensing
pipes; _N_, outlet for condensed oil and water; _O_ and _P_, water and
oil in separating can; _R_, outlet for water; _S_, floor of distilling
room.]
Large tanks are used for storing the oil, and cans holding 20 pounds
each are employed for shipping, three of these cans being placed in a
wooden case.
The peppermint hay which remains after distillation is used as a
fertilizer or is fed to stock.
PEPPERMINT OIL AND MENTHOL.
Peppermint leaves and flowering tops are official in the Eighth
Decennial Revision of the United States Pharmacopœia, as are likewise
the following products and preparations derived from these parts: Oil
of peppermint, menthol, spirit of peppermint, and peppermint water.
The United States Pharmacopœia describes oil of peppermint as “a
colorless liquid, having the characteristic strong odor of peppermint
and a strongly aromatic pungent taste, followed by a sensation of cold
when air is drawn into the mouth.” It is largely used in medicine,
internally as a stimulant and carminative, and externally to relieve
neuralgic and rheumatic conditions. It is also used for flavoring and
scenting confectionery, cordials, and cosmetics. There is a slight
difference in the odor of white and black peppermint oil, the black
being more pungent and less agreeable in fragrance than the white,
which has a much finer odor, but, as already indicated, the white mint
is less hardy than the black and yields a smaller quantity of oil.
The Japanese oil of peppermint, which, as pointed out elsewhere in
these pages, is obtained from a different species of mint than that
which produces the true oil of peppermint, is very inferior to the last
named. It has a very unpleasant odor and a bitter, disagreeable taste,
but it is a heavy oil and contains a higher percentage of menthol and,
being a very much cheaper oil, it is liable to be used as an adulterant
of true peppermint oil.
Menthol, formerly known as peppermint camphor, is the solid constituent
of oil of peppermint, obtained by subjecting the distilled oil to
an exceedingly low temperature by means of a freezing mixture. Its
properties are about the same as those of oil of peppermint, only
somewhat intensified. It is very largely made up into cones or pencils,
which furnish a popular remedy, to be applied externally or inhaled,
for the relief of headache, neuralgia, catarrh, asthma, and kindred
affections. It is also largely employed in other forms of medication.
The name “pipmenthol” has been applied to the menthol obtained from the
American oil, to distinguish it from the Japanese menthol. Pipmenthol
is said to have a distinct odor of peppermint, while the Japanese
menthol has but a slight peppermint odor.
EXPORT OF PEPPERMINT OIL.
The exports of peppermint oil during the fiscal year ended June 30,
1904, amounted to 42,939 pounds, valued at $124,728. Germany and the
United Kingdom were the largest consumers, the former receiving 22,372
pounds, valued at $65,505, and the latter 11,558 pounds, worth $31,798.
The following tables show the export of peppermint oil, by countries,
for the fiscal year ended June 30, 1904, and the quantities and values
of peppermint oil exported for a period of ten years, from July 1,
1894, to June 30, 1904, inclusive:
_Exports of peppermint oil, by countries, for the fiscal year ended
June 30, 1904._[6]
——————————————————————————————————+—————————+———————
Country. |Quantity.| Value.
——————————————————————————————————+—————————+———————
|_Pounds._|
Belgium | 473| $1,585
France | 3,054| 10,059
Germany | 22,372| 65,505
Italy | 826| 2,471
Netherlands | 590| 1,934
United Kingdom | 11,558| 31,798
Dominion of Canada: | |
Nova Scotia, New Brunswick, etc.| 85| 234
Quebec, Ontario, Manitoba, etc. | 1,165| 3,306
Newfoundland and Labrador | 94| 204
West Indies: | |
British | 183| 700
Cuba | 29| 87
Danish | 17| 55
Dutch | 20| 61
Argentina | 1,237| 3,504
British Guiana | 10| 31
Peru | 50| 175
British Australasia | 1,176| 3,019
+—————————+———————
Total | 42,939|124,728
——————————————————————————————————+—————————+———————
_Quantities and values of peppermint oil exported during the fiscal
years 1895 to 1904, inclusive._[7]
————————————+—————————+—————————
Fiscal year.|Quantity.| Value.
————————————+—————————+—————————
|_Pounds._|
1895 | 87,633 | $194,616
1896 | 85,290 | 174,810
1897 | 162,492 | 257,484
1898 | 145,375 | 180,811
1899 | 117,462 | 118,227
1900 | 89,558 | 90,298
1901 | 60,166 | 63,672
1902 | 36,301 | 54,898
1903 | 13,033 | 34,943
1904 | 42,939 | 124,728
————————————+—————————+—————————
FOOTNOTES:
[6] The Foreign Commerce and Navigation of the United States for the
year ending June 30, 1904, vol. 1, p. 531, Bureau of Statistics,
Department of Commerce and Labor.
[7] From The Foreign Commerce and Navigation of the United States for
the year ending June 30, 1902, vol. 2, p. 309. Bureau of Statistics,
Treasury Department; and The Foreign Commerce and Navigation of the
United States for the year ending June 30, 1904, vol. 1, p. 192, Bureau
of Statistics, Department of Commerce and Labor.
PRICES OF PEPPERMINT OIL.
The price of peppermint oil was very low for a few years prior to
1900, the enormous production of 1897 resulting in a great drop in
price. The lowest price paid for it was in 1899, when it brought only
75 cents per pound. As a result of the low price a great many mint
farmers restricted the area of their mint plantations or altogether
abandoned peppermint cultivation. The smaller output of the following
seasons again sent prices up, and in 1902 the oil sold as high as
$4.75 a pound, which price was maintained until early in 1903, when it
gradually declined, until toward the end of that year it reached $2.20
per pound.
The following table[8] gives the highest and lowest prices of
peppermint oil in bulk from 1873 to September 16, 1905:
———————+————————+———————
Year. |Highest.|Lowest.
———————+————————+———————
1873 | $3.15 | $3.15
1874 | 5.25 | 3.75
1875 | 5.50 | 3.20
1876 | 3.75 | 2.40
1877 | 3.00 | 1.75
1878 | 2.00 | 1.50
1879 | 2.65 | 1.45
1880 | 2.87 | 2.60
1881 | 2.85 | 2.35
1882 | 2.50 | 2.25
1883 | 2.60 | 2.20
1884 | 3.00 | 2.50
1885 | 4.37 | 2.75
1886 | 3.60 | 2.75
1887 | 2.75 | 1.90
1888 | 2.40 | 1.75
1889 | 2.30 | 1.80
1890 | 2.40 | 1.80
1891 | 2.50 | 2.45
1892 | 2.50 | 2.15
1893 | 2.45 | 2.15
1894 | 2.45 | 1.70
1895 | 2.00 | 1.70
1896 | 1.85 | 1.20
1897 | 1.25 | .90
1898 | .90 | .80
1899 | .90 | .75
1900 | 1.10 | .80
1901 | 1.80 | 1.10
1902 | 4.75 | 1.70
1903 | 4.75 | 2.20
1904 | 3.75 | 2.65
1905[9]| 3.45 | 2.25
———————+————————+———————
The good prices of the past few years have caused many farmers to look
again to peppermint as a profitable crop, as noted in increased areas
under cultivation in many localities. This is the case not only in
Michigan and Indiana, but also in New York, where for many years the
peppermint industry has been declining. Thus, if favorable conditions
of growth prevail, an increased production may be looked for within the
next few years, which will have the effect of again depressing prices.
As is the case with other products the prices of which are subject to
great fluctuations, the condition of the market for peppermint oil
needs to be closely observed. The cost of cultivation per acre has been
stated at from $12 to $14, and, with a charge of 25 cents per pound of
oil for distillation, the market price may easily fall below the cost
of production.
FOOTNOTES:
[8] From Oil, Paint, and Drug Reporter, September 18, 1905, p. 7.
[9] To September 16.Project Gutenberg
Peppermint
Henkel, Alice
Chimera55
Graduate