SEMEN SINAPIS NIGRÆ.

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.

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 1s. 3d. to 6s. 8d. per quarter, but in 1347 and 1376 it was as high as 15s. and 16s.[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.

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

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.

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

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.

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.

SEMEN SINAPIS ALBÆ.

Botanical Origin—Brassica alba Hook. f. et Th. (Sinapis alba L.) This plant appears to belong to the more southern countries of Europe and Western Asia. According to Chinese authors[294] it was introduced into China from the latter region. Its cultivation in England is of recent introduction, but is rapidly extending.[295] The plant is not uncommon as a weed on cultivated land.

History—White mustard was used in former times indiscriminately with the brown. In the materia medica of the London Pharmacopœia of 1720 the two sorts are separately prescribed. The important chemical distinction between them was first made known in 1831 by Boutron-Charlard and Robiquet.[296]

Production—White mustard is grown as an agricultural crop in Essex and Cambridgeshire.

Description—Brassica alba differs from B. nigra in having the pods bristly and spreading. They are about an inch long, half the length being occupied by a flat veiny beak. Each pod contains 4 to 6 yellowish seeds about ¹/₁₂ of an inch in diameter and ⅒ of a grain in weight. The brittle, nearly transparent and colourless testa encloses an embryo of a bright pure yellow and of the same structure as that of black mustard. The surface of the testa is likewise pitted in a reticulate manner, but so finely that it appears smooth except under a high magnifying power.

When triturated with water the seeds form a yellowish emulsion of very pungent taste, but it is inodorous and does not under any circumstances yield a volatile oil. The powdered seeds made into a paste with cold water act as a highly stimulating cataplasm. The entire seeds yield to cold water an abundance of mucilage.

Microscopic Structure—The epidermal cells of white mustard afford a good illustration of a mucilage-yielding layer such as is met with, under many variations, in the seeds of numerous plants. The cuticle consists of large vaulted cells, exhibiting very regular hexagonal outlines when cut across.[297] The inner layer of the epidermis is made up of thin-walled cells, which when moistened swell and give off the mucilage. In the dry state or seen under oil, the outlines of the single cells of this layer are not distinguishable. The tissue of the cotyledons is loaded with drops of fatty oil and with granular albuminoid matter; starch which is present in the seed while young, is altogether absent when the latter reaches maturity.

Chemical Composition—White mustard deprived of fatty oil yields to boiling alcohol colourless crystals of Sinalbin, an indifferent substance, readily soluble in cold water, but sparingly in cold alcohol. From the able investigations of Will (1870) it follows, that it is to be regarded as composed of three bodies, namely:

represents according to Will the composition of sinalbin. It is actually resolved into these three substances when placed at ordinary temperatures, in contact with water and Myrosin, the latter of which is a constituent of white mustard as well as of brown (p. 66). The liquid becomes turbid, the first of the above-named substances separates (together with coagulated albumin) as an oily liquid, not soluble in water, but dissolving in alcohol or ether. This Sulphocyanate of Acrinyl is the rubefacient and vesicating principle of white mustard. It does not pre-exist, as shown by Will, in the seed, and cannot be obtained by distillation. By treating it with a salt of silver, Will obtained crystals of cyanide of acrinyl, C₈H₇NO: by warming it (or sinalbin itself, or an alcoholic extract of the seed) with caustic potash, sulphocyanide of potassium is produced. The presence of the latter may be indicated by adding a drop of perchloride of iron, when a blood-red coloration will be produced.[298]

Sulphate of Sinapine imparts to the emulsion of white mustard, in which it is formed, an acid reaction. Sinapine is itself an alkaloid, which has not yet been isolated, as it is very liable to change. Thus its solution on addition of a trace of alkali immediately assumes a bright yellow colour indicating decomposition, and a similar colour is produced in an aqueous extract of the seed.

The above statements show, that the chemical properties of sinalbin and its derivatives correspond closely with those of sinigrin (p. 66) and the substances which make their appearance in an emulsion of black mustard.

The other constituents of white mustard seed are nearly the same as those of black. The fat oil appears to yield in addition to the acids mentioned at p. 67, Benic or Behenic Acid, C₂₂H₄₄O₂. White mustard is said to be richer than black in myrosin, so that, as explained in the previous article, the pungency of the latter may be often increased by an addition of white mustard. By burning white mustard dried at 100° C., with soda-lime, we obtained from 4·20 to 4·30 per cent. of nitrogen, answering to about 28 per cent. of protein substances.[299] The fixed oil of the seed amounts to 22 per cent. The mucilage as yielded by the epidermis is precipitable by alcohol, neutral lead acetate, or ferric chloride, and is soluble in water after drying.

Erucin and Sinapic Acid, mentioned by Simon (1838)[300] as peculiar constituents of white mustard, are altogether doubtful, yet may deserve further investigation. The sinapic acid of Von Babo and Hirschbrunn[301] (1852) is a product of the decomposition of sinapine.

Uses—White Mustard seed reduced to powder and made into a paste with cold water act as a powerful stimulant when applied to the skin, notwithstanding that such paste is entirely wanting in essential oil. But for sinapisms they are actually used only in the form of the Flour of Mustard which is prepared for the table and which contains also Brown Mustard seed.

RADIX ARMORACIÆ.

Botanical Origin—Cochlearia Armoracia L., a common perennial with a stout tapering root, large coarse oblong leaves with long stalks, and erect flowering racemes 2 to 3 feet high. It is indigenous to the eastern parts of Europe, from the Caspian through Russia and Poland to Finland. In Britain and in other parts of Europe from Sicily to the polar circle, it occurs cultivated or semi-wild; in the opinion of Schübeler[302] it is not truly indigenous to Norway.

History—The vernacular name Armon is stated by Pliny[303] to be used in the Pontic regions to designate the Armoracia of the Romans, the Wild Radish (ῤαϕανὶς ἀγρία) of the Greeks, a plant which cannot be positively identified with that under notice.

Horse-radish is called in the Russian language Chren, in Lithuanian Krenai, in Illyrian Kren, a name which has passed into several German dialects, and as Cran or Cranson into French.

From these and similar facts, De Candolle[304] has drawn the conclusion that the propagation of the plant has travelled from Eastern to Western Europe.

Both the root and leaves of horse-radish were used as a medicine and also eaten with food in Germany and Denmark during the middle ages.[305] But the use of the former was not common in England until a much later period. The plant is mentioned in the Meddygon Myddfai and was known in England as Red-cole in the time of Turner, 1568, but is not quoted by him[306] as used in food, nor is it noticed by Boorde,[307] 1542, in his chapter on edible roots. Gerarde[308] at the end of the 16th century remarks that horse-radish—“is commonly used among the Germans for sauce to eat fish with, and such like meats, as we do mustard.” Half a century later the taste for horse-radish had begun to prevail in England. Coles[309] (1657) states that the root sliced thin and mixed with vinegar is eaten as a sauce with meat as among the Germans. That the use of horse-radish in France had the same origin is proved by its old French name Moutarde des Allemands.

The root to which certain medicinal properties had always been assigned, was included in the materia medica of the London Pharmacopœias of the last century under the name of Raphanus rusticanus.

Description—The root which in good ground often attains a length of 3 feet and nearly an inch in diameter, is enlarged in its upper part into a crown, usually dividing into a few short branches each surmounted by a tuft of leaves, and annulated by the scars of fallen foliage; below the crown it tapers slightly, and then for some distance is often almost cylindrical, throwing off here and there filiform and long slender cylindrical roots, and finally dividing into two or three branches. The root is of a light yellowish-brown; internally it is fleshy and perfectly white, and has a short non-fibrous fracture. Before it is broken it is inodorous, but when comminuted it immediately exhales its characteristic pungent smell. Its well-known pungent taste is not lost in the root carefully dried and not kept too long.

A transverse section of the fresh root displays a large central column with a radiate and concentric arrangement of its tissues, which are separated by a small greyish circle from the bark, whose breadth is from ½ to 2 lines. In the root branches there is neither a well-defined liber nor a true pith. The short leaf-bearing branches include a large pith surrounded by a circle of woody bundles. The bark adheres strongly to the central portion, in which zones of annual growth are easily perceptible, at least in older specimens.

Microscopic Structure—The corky layer is made up of small tabular cells as usual in suberous coats. In the succeeding zone of the middle bark, thick-walled yellow cells are scattered through the parenchyme, chiefly at the boundary line of the corky layer. In the root the cellular envelope is not strikingly separated from the liber, whilst in its leafy branches this separation is well marked by wedge-shaped liber bundles, which are accompanied by a group of the yellow longitudinally-elongated stone-cells. The woody bundles contain a few short yellow vessels, accompanied by bundles of prosenchymatous, not properly woody cells. The centre, in the root, shows these woody bundles to be separated by the medullary parenchyma; in the branches the central column consists of an uniform pith without woody bundles, the latter forming a circle close to the cambium. The parenchyma of the whole root collected in spring is loaded with small starch granules.

Chemical Composition—Among the constituents of horse-radish root (the chemical history of which is however far from perfect) the volatile oil is the most interesting. The fresh root submitted to distillation with water in a glass retort, yields about ½ per mille of oil which is identical with that of Black Mustard as proved in 1843 by Hubatka. He combined it with ammonia and obtained crystals of thiosinammine, the composition of which agreed with the thiosinammine from mustard oil.

An alcoholic extract of the root is devoid of the odour of the oil, but this is quickly evolved on addition of an emulsion of White Mustard. The essential oil does not therefore pre-exist, but only sinigrin (myronate of potassium) and an albuminoid matter (myrosin) by whose mutual reaction in the presence of water it is formed (p. 66). This process does not go on in the growing root, perhaps because the two principles in question are not contained in the same cells, or else exist together in some condition that does not allow of their acting on each other,—a state of things analogous to that occurring in the leaves of Lauro-cerasus.

By exhausting the root with water either cold or hot, the sinigrin is decomposed and a considerable proportion of bisulphate is found in the concentrated decoction. Alcohol removes from the root some fatty matter and sugar (Winckler 1849). Salts of iron do not alter thin slices of it, tannic matters being absent. The presence of myrosin, which at present has been inferred rather than proved, ought to be further investigated. The root dried at 100° C afforded 11·15 per cent. of ash to Mutschler (1878).

Uses—An infusion or a distilled spirit of horse-radish is reputed stimulant, diaphoretic, and diuretic, but is not often employed.

Substitute—In India the root of Moringa pterygosperma Gärtn. is considered a substitute for horse-radish. It yields by distillation an essential oil of disgusting odour which Broughton, who obtained it in minute quantity, has assured us is not identical with that of mustard or of garlic.