_Black, Brown or Red Mustard_; F. _Moutarde noire ou grise_; G.
_Schwarzer Senf_.
=Botanical Origin=—_Brassica nigra_ Koch (_Sinapis nigra_ L.). Black
Mustard is found wild over the whole of Europe excepting the extreme
north. It also occurs in Northern Africa, Asia Minor, Mesopotamia, the
Caucasian region, Western India, as well as in Southern Siberia and
China. By cultivation, which is conducted on a large scale in many
countries (as Alsace, Bohemia, Holland, England and Italy), it has
doubtless been diffused through regions where it did not anciently
exist. It has now become naturalized both in North and South America.
=History=—Mustard was well known to the ancients. Theophrastus mentions
it as Νάπμ,—Dioscorides as Νάπμ or Σίνηπι. Pliny notices three kinds
which have been referred by Fée[280] to _Brassica nigra_ Koch, _B.
alba_ Hook. f. et Th., and to a South European species, _Diplotaxis
erucoides_ DC. (_Sinapis erucoides_ L.). The use of mustard seems up
to this period to have been more medicinal than dietetic. But from
an edict of Diocletian, A.D. 301[281] in which it is mentioned along
with alimentary substances, we must suppose it was then regarded as a
condiment at least in the eastern parts of the Roman Empire.
[279] See Tingling, J. F. B., _The poppy-plague and England’s crime_,
London, 1876 (192 p.); Turner, F. S. (Secretary of the Anglo-Oriental
Society for the Suppression of the Opium Trade), _British Opium Policy
and its results to India and China_. London, 1876 (308 pages); Sir Edw.
Fry, _England, China, and Opium_, 1878 (61 p.).
[280] _Botanique et Matière Méd. de Pline_, ii. (1833) 446.
[281] Mommsen in _Berichte der sächs. Gesellsch. der Wissenschaften zu
Leipzig_, 1851. 1-80.
In Europe during the middle ages mustard was a valued accompaniment
to food, especially to the salted meat which constituted a large
portion of the diet of our ancestors during the winter.[282] In the
Welsh “Meddygon Myddvai,” of the 13th century, a paragraph is devoted
to the “Virtues of Mustard.” In household accounts of the 13th and
14th centuries, mustard under the name of _Senapium_ is of constant
occurrence.
Mustard was then cultivated in England, but not as it would seem very
extensively. The price of the seed between A.D. 1285 and 1395 varied
from 1_s._ 3_d._ to 6_s._ 8_d._ per quarter, but in 1347 and 1376 it
was as high as 15_s._ and 16_s._[283] In the accounts of the abbey
of St. Germain-des-Prés in Paris, commencing A.D. 800, mustard is
specifically mentioned as a regular part of the revenue of the convent
lands.[284]
The essential oil of mustard was, apparently, noticed about the year
1660 by Nicolas Le Febvre (see in the article Rad. Inulae), more
distinctly in 1732 by Boerhaave. Its acridity and high specific
gravity were pointed out by Murray.[285] Thibierge in 1819 observed
that sulphur was one of the constituents of the oil, and Guibourt[286]
stated that it is not pre-existing in the seed.
=Production=—Mustard is grown in England only on the richest alluvial
soils, and chiefly in the counties of Lincolnshire and Yorkshire. Very
good seed is produced in Holland.
=Description=—The pod of _Brassica nigra_ is smooth, erect, and closely
pressed against the axis of the long slender raceme. It has a strong
nerve on each of its two valves and contains in each cell from 4 to
6 spherical or slightly oval seeds. The seeds are about ¹/₂₅ of an
inch in diameter and ¹/₅₀ of a grain in weight; they are of a dark
reddish-brown. The surface is reticulated with minute pits, and often
more or less covered with a whitish pellicle which gives to some seeds
a grey colour.[287] The testa which is thin, brittle and translucent
encloses an exalbuminous embryo having two short cotyledons folded
together longitudinally and forming a sort of trough in which the
radicle lies bent up. The embryo thus coiled into a ball completely
fills the testa; the outer cotyledon is thicker than the inner, which
viewed in transverse section seems to hold the radicle as a pair
of forceps. The seeds when pulverized have a greenish yellow hue.
Masticated they have for an instant a bitterish taste which however
quickly becomes pungent. When triturated with water they afford a
yellowish emulsion emitting a pungent acrid vapour which affects the
eyes, and has a strong acid reaction. The seeds powdered dry have no
such pungency. When the seeds are triturated with solution of potash,
the pungent odour is not evolved; nor when they are boiled in water.
Neither is the acridity developed on triturating them with alcohol,
dilute mineral acids, or solution of tannin, or even with water when
they have been kept in powder for a long time.
[282] Enclosed pasture land in England was rare, and there was but
scanty provision for preserving stock through the winter, root crops
being unknown. Hence in November there was a general slaughtering of
sheep and oxen, the flesh of which was salted for winter use.—See also
_Pharm. Journ._ viii. (1876, April 27) 862.
[283] Rogers, _Hist. of Agriculture and Prices in England_, i. (1866)
223.
[284] Guérard, _Polyptique de l’Abbé Irminon_, Paris, i. (1844) 715.
[285] _Apparatus medicaminum_, ii. (1794) 399.
[286] _Journ. de Pharm._ xvii. (1831) 360.
[287] The grey colour of the seed, which is attributed to rain during
the ripening, is very detrimental to its value. The great aim of the
grower is to produce seed of a bright reddish-brown, with no grey seed
intermixed.
=Microscopic Structure=—The whitish pellicle already mentioned, which
covers the seed, is made up of hexagonal tabular cells. The epidermis
consists of one row of densely packed brown cells, radially elongated
and having strong lateral and inner walls. Their outer walls on the
other hand are thin and not coloured; they are not clearly obvious
when seen under oil, but swell up very considerably in presence of
water, emitting mucilage.[288] Seeds immersed in water become therefore
covered with a glossy envelope, levelling down the superficial
inequalities, so that the wet seed appears smooth. The tissue of the
cotyledons exhibits large drops of fatty oil and granules of albumin.
=Chemical Composition=—By distilling brown mustard with water, the seed
having been previously macerated, the pungent principle, _Essential Oil
of Mustard_, is obtained.
The oil, which has the composition SCN(C₃H⁵), (allyl isosulphocyanate),
boils at 148° C.; it has a sp. gr. of 1·017, no rotatory power, and
is soluble without coloration or turbidity in three times its weight
or more of cold strong sulphuric acid. To this oil is due the pungent
smell and taste of mustard and its inflammatory action on the skin. As
already pointed out, mustard oil is not present in the dry seeds, but
is produced only after they have been comminuted and mixed with water,
the temperature of which should not exceed 50° C.
The remarkable reaction which gives rise to the formation of
mustard oil was explained by Will and Körner in 1863. They obtained
from mustard a crystallizable substance, then termed _Myronate of
potassium_, now called _Sinigrin_. It is to be regarded, according to
the admirable investigations of these chemists, as a compound of
Isosulphocyanate of allyl or mustard oil C₄ H₆ NS
Bisulphate of potassium H KS O₄
Sugar (dextro-glucose) C₆ H₁₂ O₆
-----------------
so that the formula C₁₀ H₁₈ KNS₂ O₁₀
is that of sinigrin. It does in fact split into the above-mentioned
three substances when dissolved in water and brought into contact with
_Myrosin_.
[288] Most minutely described and figured by F. von Höhnel, in
Haberlandt’s _Untersuchungen auf dem Gebiete des Pflanzenbaues_, i.
(Vienna, 1875) 171-202.
This albuminous body discovered by Bussy in 1839, but the composition
of which has not been made out, likewise undergoes a certain
decomposition under these circumstances. Sinigrin may likewise be
decomposed by alkalis and, according to Ludwig and Lange, by silver
nitrate. These chemists obtained sinigrin from the seeds in the
proportion of 0·5 per cent.; Will and Körner got 0·5 to 0·6 per cent.
The extraction of the substance is therefore attended with great loss,
as the minimum yield of volatile oil, 0·42 per cent. indicates 2·36 of
potassium myronate.
The aqueous solution of myrosin coagulates at 60° C. and then becomes
inactive: hence mustard seed which has been heated to 100° C. or has
been roasted yields no volatile oil, nor does it yield any if powdered
and introduced at once into boiling water. The proportion of myrosin in
mustard has not been exactly determined. The total amount of nitrogen
in the seed is 2·9 per cent. (Hoffmann) which would correspond to 18
per cent. of myrosin, supposing the proportion of nitrogen in that
substance to be the same as in albumin, and the total quantity of
nitrogen to belong to it. Sometimes black mustard contains so little of
it, that an emulsion of white mustard requires to be added in order to
develop all the volatile oil it is capable of yielding.
An emulsion of mustard or a solution of pure sinigrin brought into
contact with myrosin, frequently deposits sulphur by decomposition of
the allyl sulphocyanide, hence crude oil of mustard sometimes contains
a considerable proportion (even half) of _Allyl cyanide_, C₄H₅N,
distinguished by its lower sp. gr. (0·839) and lower boiling point
(118° C.).
The seeds, roots, or herbaceous part of many other plants of the order
_Cruciferæ_ yield a volatile oil composed in part of mustard oil and in
part of allyl sulphide
C₂H₅}
C₆H₁₀S = } S,
C₃H₅}
which latter is likewise obtainable from the bulbs of garlic. Many
_Cruciferæ_ afford from their roots or seeds chiefly or solely oil
of mustard, and from their leaves oil of garlic. As to other plants,
the roots of _Reseda lutea_ L. and _R. luteola_ L. have been shown by
Volhard (1871) to afford oil of mustard.[289] The strong smell given
off by the crushed seeds or roots of several Mimoseæ, as for instance,
_Albizzia lophantha_ Benth. (_Acacia_ Willd.) is perhaps due to some
allied compound.
The artificial preparation of mustard oil was discovered in 1855 by
Zinin, and at the same time also by Berthelot and De Luca. It may be
obtained in decomposing bromide of allyl by means of sulphocyanate of
ammonium:—
C₃H₅Br · SCN(NH₄) = NH₄Br · C₃H₅SCN.
The liquid C₃H₅SCN, boiling at 161°, is sulphocyanate of allyl; if it
is gently warmed with a little alcoholic potash, and then acidulated,
the red coloration of ferric sulphocyanate is produced on addition of
perchloride of iron, but by submitting the sulphocyanate of allyl to
distillation it is at once transformed in the isosulphocyanate, _i.e._
in mustard oil; the latter is not coloured by ferric salts, but it
would appear that in the cold emulsion of mustard, even at 0°, a little
sulphocyanate makes also its appearance.
Mustard submitted to pressure affords about 23 per cent.[290] of a
mild-tasting, inodorous, non-drying oil, solidifying when cooled to
-17·5° C., and consisting of the glycerin compounds of stearic, oleic
and _Erucic_ or _Brassic Acid_. The last named acid, C₂₂H₄₂O₂, occurs
also in the fixed oil of white mustard and of rape, and is homologous
with oleic acid. Darby (1849) has pointed out the existence of another
body, _Sinapoleic Acid_, C₂₀H₃⁸O₂, which occurs in the fixed oil of
both black and white mustard. Goldschmiedt, in 1874, ascertained the
presence also of _Behenic Acid_, C₂₂H₄₄O₂ in black mustard. Sinigrin
being not altered by the extraction of the fatty oil, either by
pressure or by means of bisulphide of carbon, the powdered seed,
deprived of fatty oil, still yields the whole amount of the irritating
“essential” oil. This important fact has been ingeniously used by
Rigollot[291] for the preparation of his mustard paper.
[289] See also _Radix Armoraciæ_, p. 68.
[290] I have obtained as much as 33·8 per cent. by means of boiling
ether.—F. A. F.
[291] _Journ. de Pharm._ vi. (1867) 269.
Mustard seed when ripe is devoid of starch; the mucilage which its
epidermis affords amounts to 19 per cent. of the seed (Hoffmann).
The ash constituents amounting to 4 per cent. consist chiefly of the
phosphates of calcium, magnesium, and potassium.
=Uses=—Black mustard is employed in the form of poultice as a powerful
external stimulant; but it is rarely used in its pure state, as
the _Flour of Mustard_ prepared for the table, which contains in
addition white mustard, answers perfectly well and is at hand in every
house.[292]
The essential oil of mustard dissolved in spirit of wine is
occasionally prescribed as a liniment.
=Substitute=—_Brassica juncea_ Hook. f. et Th. (_Sinapis juncea_
L.) is extensively cultivated throughout India (where _B. nigra_ is
rarely grown), Central Africa, and generally in warm countries where
it replaces _B. nigra_ and is applied to the same uses. Its seeds
constitute a portion of the mustard of Europe, as we may infer from
the fact that British India exported in the year 1871-72, of “_Mustard
seed_” 1418 tons, of which 790 tons were shipped to the United Kingdom,
and 516 tons to France.[293] _B. juncea_ is largely grown in the south
of Russia and in the steppes north-east of the Caspian where it appears
to flourish particularly well in the saline soil. At Sarepta in the
Government of Saratov, an establishment has existed since the beginning
of the present century where this sort of mustard is prepared for use
to the extent of 800 tons of seed annually. The seeds make a fine
yellow powder employed both for culinary and medicinal purposes. By
pressure they yield more than 20 per cent. of fixed oil which is used
in Russia like the best olive oil. The seeds closely resemble those
of _B. nigra_ and afford when distilled the same essential oil; it is
largely made at Kiew.