VII.

PTELEA TRIFOLIATA.

BY E. M. HALE, M.D., OF CHICAGO.

THE Ptelea trifoliata of Linnæus, is a shrub or small tree of the natural order Rutacea; or, according to earlier views, of an order Xanthoxylaceæ, or, still earlier, of the artificial class Monoecia and order Tetra-pentandria, of the Sexual System of Linnæus.

It is figured as follows:

Miller, Icones, t. 211;

Gærtner, de Fructibus et Seminibus, pl. 49;

Schkuhr, Botanisches Handbuch, pl. 25;

Guimpel, Fremden Holzarten, pl. 74;

La Marck, Planches de Botanique de l'Encyclopédie, pl. 84; Duhamel, Arbres et Arbustes en Pleine Terre, 2d ed., vol. 1, pl. 57;

Dictionnaire des Sciences Naturelles, pl. 128;

Mémoires du Muséum d'Histoire Naturelle, vol. 12, pl. 26; Gray, Genera Illustrata, pl. 157;

Dillenius, Horti Elthamensis Plant. Rar., pl. 122;

Payer, Organogénie, pl. 24;

Agardh, Theoria Systematis Plantarum, pl. 19;

Loudon, Arboretum Britannicum, vol. 5, pl. 59.

The Xanthoxylaceæ included those Rutacea which have unisexual flowers. The genus Ptelea has polygamous flowers, with four or five stamens, with samaroid, two-celled fruit, but one

celled by abortion. Its name is the Greek for Elm, given because of the resemblance of the samaroid fruits.

Its six known species are all North-American. Three are Mexican, — P. pentandra, P. podocarpa, and P. angustifolia. P. mollis, of the Carolinas, is clothed with a silky pubesence. P. Baldwinii, of East Florida, has minute leaves with obtuse leaflets.

The remaining species, Ptelea trifoliata, Three-leaved Ptelea, Hop-tree, Wing-seed, Wafer-ash (known in Britain as Shrubby trefoil and Tree trefoil, in France as Orme de Samarie à trois feuilles, and in Germany as Dreiblättrige Lederblume), is indigenous throughout the United States, from the East to beyond the Mississippi, and even to Texas, in moist, shady places, and on the borders of woods and among rocks. It is a tall shrub, but under cultivation at Gordon Castle, Bannfshire, Scotland, it had, in 1835, reached the height of forty-five feet, with a trunk fifteen inches in diameter, and with branches extending twentyseven feet from side to side.

Two varieties have been found,- one with five leaflets (P. pentaphylla, Moench); the other with the branches, petioles, and under surface of the leaves clothed with a soft tomentose pubescence, even when old (P. pubescens, Pursh).

It was originally sent to England by Bannister, but, being lost, was re-introduced by Catesby in 1724, from Carolina. It is common in the gardens of Europe; and in the Jardin des Plantes, at Paris, a tree may be seen, the crown of which had, in sixty years from planting, attained a diameter of forty-five feet.

[To this same Rue family belong the Xanthoxylum Americanum, Northern Prickly-ash, and X. Carolinianum, the Pricklyash of the South. And in some respects they are medicinal as well as botanical analogues of the Ptelea.]

Pharmaceutical History. - The bark of the root is the officinal portion. It yields its properties to boiling water, but alco

hol is the best solvent. It is, when dried, of a light brownish-yellow color externally, in cylindrical rolls or quills, a line or two in thickness, and from one to several inches in length, irregularly wrinkled and furrowed externally, with broad transverse lines or rings at short but irregular intervals, and covered with a thin epidermis; internally it is yellowish-white, but becomes darker on exposure, and is wrinkled longitudinally. It is brittle, with an almost smooth resinous fracture, granular under the microscope, resembling wax. It has a peculiar smell, which some describe as like that of liquorice root; but to me the bark, and especially the tincture, strongly resembles in odor that of the boiling linseed oil used in the manufacture of white paint. The taste is peculiar, almost indescribable: bitter, resinous, pungent, acrid, very disagreeable, speedily and powerfully acting on the mouth and fauces; and its pungency is persistent, owing probably to the oil.

The tincture of the bark should be made with the strongest alcohol: the addition of a small quantity of water causes it to turn as milky as the balsam of Copaiva under similar circumstances.

A tincture trituration may be made from the mother-tincture, and is a very eligible preparation.

The flowers, fruit, leaves, and bark of the branches, all possess the same medicinal qualities as the root, but in a less degree. I have used the tincture of the hardly-ripe fruit. The woody portion of the shrub is but feebly medicinal. Ptelein, or the active principle, may be used in tincture, as it is perfectly soluble in alcohol; but the triturations are preferable. (See Chemical History.)

I do not know that for medicinal preparations the fresh bark possesses any superiority over the dried. The bark should be gathered in the fall, at the time of its greatest strength, after its constituent qualities have been fully elaborated in its cells. The leaves should be used when fully developed, but before the §II.-15

ripening; the flowers, just before the petals drop; and the fruits, just at the period of ripening.

The process of drying these portions should be conducted in a warm, shaded place, with care that they do not become moldy, or infested by insects of any kind.

CHEMICAL HISTORY.-An oleo-resin, improperly called Ptelein, is considered the active principle of the Ptelea. It is described as of the consistence of thick syrup or molasses, dark-brown in mass, much lighter when in thin layers, and having a peculiar odor, somewhat similar to that of the extract of liquorice, and an oily, bitterish, acrid, persistent taste, peculiar and rather disagreeable, and acting powerfully on the fauces. It is soluble in alcohol, ether, oil of turpentine, and rather imperfectly in alkaline solutions; insoluble in acids and water. It imparts a slight milky color to water, and separates into two portions, one of which floats on the water, while the other sinks. Acetic acid added to the alcoholic or ethereal solutions does not disturb them unless added in excess. Water added to the alcoholic solution produces a milky color, precipitating the resin; added to the ethereal solution, it separates the oil, which floats on the surface. The bark was not subjected to a chemical analysis until 1862, when Geo. M. Smyser, of Philadelphia, presented an Inaugural Essay to the Philadelphia College of Pharmacy, having for its subject Ptelea trifoliata. The following were the experiments:

"First. A cold infusion was prepared by percolating six drachms of the powdered leaves with water, until six ounces of liquid had passed. This was of a dark-brown color, had a bitter, aromatic taste, and an odor strongly resembling that of hops. To a portion of this infusion a solution of bichloride of mercury was added, which produced a dirty white precipitate. And, with successive portions of the infusion, sulphuric and muriatic acids produced each a precipitate. The infusion was also coagulated by heat, showing the presence of vegetable albumen.

To a portion of the infusion a few drops of tincture of chloride. of iron was added, which produced a black color. To different portions were added nitrate of silver, sulphate of copper, and a solution of gelatine, all of which produced precipitates, indicating the presence of tannic acid. The portion which was precipitated by gelatine was filtered; and, with the filtered liquid, tincture of chloride of iron produced a greenish-black color, which disappeared when the liquid was heated, showing the presence of gallic acid.

"Second. An infusion of the fruit was prepared, similar to that from the leaves. This infusion had a very bitter taste, and, upon treating it as in the former experiments, the result was the

same.

"Third. Two and a half ounces of the powdered fruit was treated with ether, to deprive it of fixed oil,-dried and treated with alcohol. To the resulting tincture, acetate of lead was added, which threw down a large quantity of coloring matter and some resin: the liquid was filtered, and treated by passing sulphureted hydrogen through it to get rid of the excess of lead, and then again filtered and heated to drive off the excess of sulphureted hydrogen. To the liquid, yet warm, water was added in drops until it began to produce a precipitate. It was then placed on a sand-bath, and evaporated to a syrupy consistence when it had cooled, it was agitated with an equal bulk of chloroform; and, when allowed to rest a few minutes, it separated into two layers, the watery liquid being on the top; this was decanted, and on evaporation yielded a small quantity of an extract of a very bitter taste. I made repeated attempts to obtain crystals from this extract, but without success. The chloroformic solution, when evaporated, gave a soft, resinous substance of a slightly acrid, bitter taste.

"Fourth. Three ounces of the powdered fruit was moistened with equal parts of alcohol and water, placed in a percolator, and the menstruum of alcohol and water passed through it until