Mustard, the name of a well known condiment as well as of the plants which produce it. In commerce two sorts of mustard seed are known, the white and the black, which are produced by plants formerly called sinapis alba and S. nigra; but in the most recent revision of the cruciferoe, the family to which they belong, sinapis is reduced to brassica, the genus which includes the cabbage and the turnip, and according to this view the mustard plants are brassica alba and B. nigra. White mustard is an annual, with a stem 1 to 2 ft. high, smooth or with a few spreading hairs; its leaves are pinnately lobed, more or less rough, the lobes coarsely toothed, with the terminal one the largest; the yellow flowers in a raceme, succeeded by pods three fourths of an inch to an inch long, bristly, upon spreading stalks and terminated by a stout flattened beak which forms more than one half of the pod and is one-seeded, while the lower part of the pod is turgid and contains several seeds; the seeds are pale brown or brownish yellow. Black mustard is a somewhat taller and smoother plant, and has less divided leaves; the pods are erect, smooth, about half an inch long, and somewhat four-sided, without the long beak, but tipped with the style, with much smaller and very dark brown seeds.

Both species are natives of Europe, and are found in the older portions of this country as naturalized weeds. The seeds of both are sold by druggists; a portion of the supply is of home growth, the rest being imported. White mustard is much used in England as a salad; the seeds are sown very thickly, and the young plants are cut while still in the seed leaf; cress (lepidium sativum) is usually sown with the mustard, and the product of the two together is known as "small salading." This species is sometimes cultivated in gardens as a pot herb or greens, the leaves being cooked while yet tender. In England mustard is much sown as a crop for forage and for green manuring, and the few experiments that have been made with it here have been favorable; sowed at the rate of about 12 lbs. to the acre, it gives an abundant crop of succulent forage, which is cut before the seeds begin to mature and fed to cattle, sheep, and swine. When either kind is raised for seed, it is cut with a sickle before it begins to drop its seed, and when dry threshed with a flail.

The great consumption of mustard seed is in the preparation of the "flour of mustard " for table use; the black seeds are the most pungent, but both kinds are used together; the seeds are crushed between rollers, then pounded in mortars, and the finer portions sifted from the husks. This was first prepared in Durham, England, by a woman who kept her process a secret, and the name " Durham mustard " is used as a trade mark by manufacturers at the present day. There is probably no article of domestic consumption more generally adulterated than flour of mustard; wheat flour to increase the weight, turmeric to give color, and cayenne to add pungency, are the most common adulterations; sometimes gypsum or white clay is used with chrome yellow (chromate of lead) to increase the color. The microscope readily shows the presence of flour, turmeric, and other vegetable admixtures; but to detect the inorganic impurities recourse must be had to chemical analysis. The husks, separated by the sieves in the manufacture of mustard, yield by expression a bland fixed oil which is used for burning and other purposes; the cake left after expressing is used as a manure, it being too pungent for cattle food. - The two kinds of mustard seed differ in their chemical constituents, which in both are rather complex.

The activity of black mustard seeds depends upon a volatile oil which does not exist ready formed in the seeds, but is developed only by the contact of water. The seeds contain myronic acid, in which sulphur is found in combination with oxygen, hydrogen, carbon, and nitrogen. Another principle is myrosine, an albuminoid which is affected by heat, alcohol, and other agents in the same manner as albumen. In the presence of water, myrosine and myronic acid react upon one another, and produce the volatile oil of mustard, or sulpho-cyanide of allyle, an exceedingly acrid and pungent liquid, which promptly blisters when applied to the skin. White mustard produces no volatile oil, but its activity depends upon a non-volatile acrid principle, which results from the action of myrosine upon sulpho-sinapisine, a constituent of the white mustard seed only. Another respect in which white mustard seed differs from the black is the mucilage contained in the husks, which is readily imparted to boiling water. - Mustard has been employed in medicine from very early times, and is mentioned by Theophrastus and Galen, and it is still much used in domestic and professional practice.

The whole seeds of the white mustard were at one time a popular remedy in dyspepsia; given in the dose of a tablespoonful, they probably served as a mechanical stimulus to torpid bowels. Serious inflammation has followed their use, and it should not be undertaken without advice. The flour of mustard is a useful emetic always at hand in case of poisoning or other emergency; the dose is from a teaspoonful to a tablespoonful stirred in a tumbler of water. As a topical stimulant, in the form of a mustard poultice or sinapism, it' is in frequent use; when the mustard is pure, its action is sufficiently prompt if mixed with an equal bulk of rye meal or wheat flour; but much of that found in the shops is already so far diluted as to be nearly inert. For this or any other use the mustard should be mixed with cold or tepid water, as hot water coagulates the myrosine and prevents the development of the active principle. The ready-made mustard plaster sold by druggists consists of the black seeds reduced to a coarse powder, which is sprinkled upon paper or stiff cloth on which a coat of thick mucilage has been spread; when dry this will keep well, and when required for use is rendered active by dipping it in tepid water and bound upon the desired spot; this is more certain in its action and more cleanly in use than any other form of sinapism.

As mustard varies so much in strength, and the skin of individuals in susceptibility, the action of mustard when applied should be closely watched, else a troublesome ulcer may be produced; this is especially necessary when the patient is unconscious. - As a condiment the uses of mustard are well known; it is mentioned by Shakespeare in "Taming of the Shrew," act 4, scene 3, though it did not become common until the time of George I. The English and Americans usually mix mustard with water and a little salt, but the French and Germans prepare it with various flavoring articles and usually cook it, depriving it of much of its pungency. The imported French mustard is of various flavors, that containing tarragon being much esteemed; celery seed, garlic, cloves, anchovies, and other things are used, and in some cases a peculiar flavor is given by stirring the mixture with a hot poker. German mustard is mixed with vinegar in which black pepper, cinnamon and other spices, and onions have been boiled, with salt and sugar added; the vinegar is used boiling, hence the mustard is very mild; it improves by keeping. - -Wild mustard, the charlock of English farmers, is brassica sinapis-trum (formerly sinapis arvensis), a troublesome weed in European agriculture, and equally so in the grain fields of some of the older parts of the United States; it bears a general resemblance to the two species already noticed, but its leaves are less divided, and the nearly smooth pods have their seed-bearing portion longer than the stout two-edged beak, which is either empty or one-seeded. The seeds of this, if buried so low that they will not germinate, retain their vitality for a long time, and have been known to vegetate when brought to the surface after having been buried more than 40 years.

Sheep are exceedingly fond of it, and are sometimes used to clear a field of charlock. In Japan, India, and other countries related species are cultivated for their leaves as food, or for their seeds to furnish oil. - The attempts to identify the plant mentioned as mustard in the New Testament have given rise to much discussion; some still hold that the black mustard, which in Palestine grows 10 or 12 ft. high, is the plant, while others refer it to Sahadora Indica, which according to Boyle was the mustard tree of the Jews. The order Salvadoracece is a small one closely related to the jasmine family. - Hedge mustard is sisymbrium officinale: a common, much-branched, unsightly weed, of the same family; it is the herb au chantre of the French, who formerly held it in esteem as a remedy for the hoarseness of singers. Tansy mustard is S. canescens, with finely divided leaves, common from New York southward.