"The inner bark of Ulmus fulva, Michaux"—(U. S. P.) (Ulmus rubra, F. A. Michaux).
COMMON NAMES AND SYNONYMS: Slippery-elm, Elm bark; Ulmi cortex, Cortex ulmi interior.
ILLUSTRATION: Bentley and Trimen, Med. Plants, 233.
Botanical Source.—Slippery-elm, also called Red elm and Moose-elm, is a tree from 20 to 60 feet in height, and 1 to 2 feet in diameter. The bark is brownish, that of the branches whitish and scabrous. The leaves are 4 to 6 inches long, 2 to 3 inches broad, lanceolate-oval, or obovate-oblong, conspicuously acuminate, doubly serrate, the upper surface scabrous, beneath tomentose-pubescent, and standing on downy foot-stalks about 4 lines long. Buds rusty-woolly. Flowers sessile, in dense, lateral clusters, and appear before the leaves. Calyx about 7-lobed, campanulate and downy; corolla none; stamens 6 or 7, short and reddish. The fruit is an orbicular samara, compressed, with a broad, membranaceous border, not fringed, and about 6 lines in diameter; seed 1, and round (W.—G.—Darlington).
History and Description.—The slippery-elm is a large tree, common to this country, especially in the western states. It grows in woods and low grounds, along fences, and in rich, dry, or moist soils, flowering in April. The official part is the inner bark, which is generally separated from the tree in long strips. The U.S. P. describes it as "in flat pieces, varying in length and width about 3 Mm. (⅛ inch) thick, tough, pale brownish-white, the inner surface finely ridged; fracture fibrous and mealy; the transverse section delicately checkered; odor slight, peculiar; taste mucilaginous, insipid"—(U.S. P.). It is also met with in the form of a ragged, fibrous mass, and in very fine powder, of a whitish-yellow or pale-fawn color, which is obtained by grinding the bark. The ground bark is often adulterated with starch.
Chemical Composition.—Slippery-elm bark consists principally of mucilage and woody fiber. Water takes up its mucilage, from which it is precipitated by the acetates of lead. The presence of starch has been demonstrated by J. U. Lloyd; at the same time it was shown that the mucilage contains a principle which decolorizes iodide of starch, the color being partly restored by diluted sulphuric acid (see Amer. Jour. Pharm., 1895, p. 459). Dr. C. W. Wright states that, when fatty substances are heated for several minutes with slippery-elm bark, in the proportion of 1 part of the bark to 128 parts of the fat, and then the fat be removed by straining, this has acquired the property of not undergoing rancidity (Amer. Jour. Pharm., 1852, p. 180).
Action, Medical Uses, and Dosage.—Elm bark is nutritive, expectorant, diuretic, demulcent, and emollient, and is a very valuable remedial agent. In mucous inflammations of the lungs, bowels, stomach, bladder, or kidneys, used freely in the form of a mucilaginous drink (1 ounce of the powdered bark to 1 pint of water), it is highly beneficial, as well as in diarrhoea, dysentery, coughs, pleurisy, strangury, and sore throat, in all of which it tends powerfully to allay the inflammation. A tablespoonful of the powder boiled in a pint of new milk, affords a nourishing diet for infants weaned from the breast, preventing the bowel complaints to which they are subject, and rendering them fat and healthy. Some physicians consider the constant use of it, during and after the seventh month of gestation, as advantageous in facilitating and causing an easy delivery; ½ pint of the infusion to be drank daily. Elm bark has likewise been successfully employed externally in cutaneous diseases, especially in obstinate cases of herpetic and syphilitic eruptions, and certainly possesses more efficient virtues than are commonly supposed. As an emollient poultice, the bark has been found very serviceable when applied to inflamed parts, suppurating tumors, fresh wounds, burns, scalds, bruises, and ulcers; and in the excruciating pains of the testes, which accompany the metastasis of mumps, whether of recent or long standing, the constant use of an elm poultice, regularly changed every 4 hours, will be found a superior remedy. Notwithstanding its general value as an application to ulcers, it will often be found injurious, especially when used as a cataplasm to ulcers of the limbs, rendering the ulcer more irritable and difficult to heal, and frequently converting a simple sore, which might be cured by astringent or other washes, into an almost intractable ulcer; much care is, therefore, required in the application of this bark externally. As an injection, the infusion will prove useful in diarrhoea, dysentery, tenesmus, and hemorrhoids, also in gonorrhoea and gleet. The powder, sprinkled on the surface of the body, will prevent and heal excoriations and chafings, and allay the itching and heat of erysipelas. As the bark increases in bulk by imbibing moisture, it has been recommended to form bougies and tents of it for the dilatation of strictures, fistulas, etc., but in urethral strictures it has proved troublesome, from the liability of the part behind the stricture breaking off in the attempt to withdraw it, and passing into the bladder. The infusion of the bark is the common form of administration, and may be drank ad libitum (J. King). (See Mucilago Ulmi.)
Related Species.—Ulmus campestris, Linné, or European elm, is official in the French Codex, being used, like our slippery-elm, for the production of a mucilage, and, being astringent, has been used against tapewoms, and in chronic skin affections, syphilitic or otherwise. Its mucilage resembles that of flaxseed (Braconnot, 1846). A bitter glucosid, not yet isolated, much mucilage, some resin, and iron-greening tannin (Johnson, 1875) are contained in it. The bark is thinner than slippery-elm bark, cinnamon-colored on both sides, and has but little odor, and a bitterish, astringent and mucilaginous taste. The tree has been introduced into New England.
Ulmus effusa, Willdenow, European black elm, also yields some elm bark.
Ulmus americana, Linné, White elm.—America. A magnificent shade tree. Its inner bark is collected in Michigan.
Ulmus alata, Michaux, or Winged elm, of the southern United States, yields a bark, which is used in making cordage.
Celtis reticulosa.—An East Indian tree, from which Prof. Dunstan has isolated skatole, the characteristic odorous principle of human faeces (Pharm. Jour. Trans., 1889).