Rhus Aromatica, Aiton—Fragrant Sumach.

Botanical name: 

Leaves of Rhus aromatica, Aiton. Syn. Sweet Sumach, Stink or Skunk Bush.


From an Inaugural Essay.

Nat. Ord. Anacardiaceae

The fragrant sumach is a small aromatic shrub, not poisonous, grow-in dry, rocky soil, in hedges and thickets, in Canada and the United States. Its height varies from three to six feet; it is erect, sometimes decumbent, branching, glabrous. The stem has a large pith, of a pinkish color, and a thin circular layer of white wood, which is covered with a thin bark, the outer surface of which is of a brown-gray color, the inner surface yellowish-green. The leaves are alternate, petiolate, exstipulate and trifoliate, with sessile, dark green, rhombic-ovate, unequally cut-toothed leaflets, two to three inches in length; pubescent when young, thickish when old. The lateral leaflets are uneven at the base, while the larger terminal one is wedge-shaped. The flowers are in close aments preceding the leaves; yellowish, with a five-lobed glandular disk. The fruit is drupaceous, subglobular, one-fourth of an inch in diameter; scarlet, densely covered with purplish-red hairs, and incloses a roundish, slightly flattened, oblong putamen. It has an odor similar to that of rose geranium, and a pleasant acidulous taste, and ripens in May and June.

The roots are branched, vary in diameter from 1/12 to ½ inch, and contain a whitish ligneous meditullium interspersed with ducts, which are not apparent to the naked eye. The bark, which is the medicinal portion, is in quills, one to four inches in length, 1/16 to ½ inch in diameter, and from 1/20 to 1/12 of an inch thick. The outer surface varies in color from light to dark brown, and is marked with corky protuberances and transverse fissures. When the corky layer is removed the outer bark is brought to view, which is of an orange-red color, is longitudinally wrinkled and transversely fissured. The inner surface is whitish or flesh-colored, and striate. The bark is brittle, breaks with a somewhat granular fracture, yields an ochre-colored powder, and has a distinct, rather pleasant odor, more marked when green than when dry; its taste is astringent, aromatic and slightly bitter when fresh, with a flavor peculiar to the plant from which it is derived. It should be collected in the spring of the year.

Upon microscopical examination the bark appears to be radially and tangentially striate, and is marked throughout with oil tubes and crystals, as is shown in the accompanying drawing.

Bark of the root Rhus aromatica, Aiton. Fig. I. A transverse section of the bark magnified to about forty or fifty diameters. The epidermis consists of a single row of cells, the walls of which are of a dark brown color. The corky layer is somewhat lighter brown, and the cells number, radially, from sixteen to twenty-five; mostly, however, eighteen. The first layer beneath the cork consists of three rows of flattened tangentially elongated parenchyma cells, followed by one of loose parenchyma and sieve tubes. The next layer consists of three rows of bast cells, interrupted by oil tubes. The succeeding layers are composed of ordinary parenchyma, sieve tubes and bast cells, some of the rows of the latter being interrupted by oil tubes the same as those just described. The medullary rays extend more than half through the bark and consist mostly of a single row of cells. The oil tubes are generally in the bast rows, arranged with some regularity. In some of the sections examined three or four of the oil tubes were found coalesced, as in Fig. I. The bark is studded with crystals, which seem to be mostly confined to the portion beyond the medullary rays. The crystals were examined under a high magnifying power, which showed them as represented in Figs. III, IV and V, the latter predominating, only a few of Figs. Ill and IV being clearly made out.

Fig. II. A longitudinal section of the bark, in a radial direction (magnified the same as Fig. I), showing the longitudinal arrangement of the tissues, oil tubes and crystals, sections of two medullary rays being quite prominent.

Fig. III represents crystals of the phosphates, Fig. IV crystals of the chlorides, and Fig. V crystals of oxalate of calcium as they appeared under a high magnifying power.

Chemical Investigation.—Five grams of the air-dry bark subjected to a heat of 100°C. until it ceased to lose weight weighed 4.651 grams, showing a loss of .349 gram — 6.98 per cent. amount of moisture.

Five grams of the air-dry bark were incinerated, and yielded .644 gram of ash, equal to 13.85 per cent., of which 16.967 per cent. was soluble in water, 74.007 per cent. soluble in hydrochloric acid, and 9.025 per cent. soluble in boiling sodic hydrate. An analysis showed the presence of potassium, sodium, aluminium, calcium and silica, combined as sulphates, chlorides and phosphates in the aqueous solution, and as phosphates and carbonates in the portion soluble in hydrochloric acid; the carbonates very likely were produced during the incineration.

Twenty grams of the powdered bark were exhausted with pure benzol by maceration and percolation; the percolate was allowed to evaporate spontaneously, yielding an extract weighing 1.272 gram — 6.36 per cent. This extract was treated with warm water, allowed to cool, filtered, and filtrate tested for alkaloids and glucosides with negative results. The undissolved extract was removed from the filters and dishes by solution in benzol, the benzol solution again evaporated to dryness, the residue treated with warm dilute sulphuric acid, allowed to cool and then filtered. The filtrate was tested for alkaloids and glucosides; negative results. The still undissolved residue was thoroughly washed with water to free from any adhering sulphuric acid, treated with absolute alcohol, filtered, and the filtrate evaporated. This left a soft oily mass, of an acid reaction, entirely soluble in ether, benzol, volatile and fixed oils, partly soluble in alcohol, sp. gr. .817, and aqueous alkalies; it has a peculiar odor, and an acrid, somewhat bitter taste, similar to that of copaiba, is soluble in concentrated sulphuric acid, with a deep brown color; strikes a similar color with concentrated nitric acid, but is insoluble in it, and gives with concentrated nitric and sulphuric acids a red-brown color, which turns lemon-yellows This substance was considered to be an oleoresin, as it left a permanent greasy stain upon paper (fixed oil), and when treated with alcohol, sp. gr. .817, and the filtrate evaporated, left a residue of a resinous nature which gave reactions with sulphuric and nitric acids, the same as those noted above. The fixed oil was boiled with,a solution of sodic hydrate, filtered and precipitated with a solution of sodic chloride; the result was a yellow-brown soap.

A fresh portion of the benzol extract was dissolved in ether, allowed to evaporate spontaneously, redissolved in ether and evaporated a second time, when the odor of butyric acid was produced. It was then treated with potassic hydrate, alcohol and sulphuric acid, and when heated the odor of ethyl butyrate was produced.

The drug exhausted with benzol was dried and treated with stronger alcohol until the percolate left no residue when evaporated; the entire percolate was carefully evaporated, the extract weighing 4.774 grams — 23.87 per cent. This extract was treated with several portions of absolute alcohol, sp. gr. .7938 at 15.6°C.

A. SOLUBLE IN ABSOLUTE ALCOHOL.—Evaporated to dryness, powdered and treated with distilled water.

a. Soluble in water, acid reaction.

a1. Precipitate by subacetate of lead.—Ochre color; was washed, suspended in water, saturated with hydrosulphuric acid to precipitate the lead, filtered, filtrate boiled to free from H2S; the amber-colored solution reduced Fehling's solution when heated, formed precipitates with solutions of gelatin, tartrate of antimony and potassium and ferric chloride, the latter giving a blue-black, which is altered only a very little upon boiling. These reactions show the presence of tannin, the reduction of Fehling's solution being due, probably, to a contamination with glucose. Negative reactions for alkaloids. The tannin. thus obtained, after continued treatment with acids, gave reactions with milk of lime, nitrate of silver and ferric salts, identical with those produced by gallic acid; this, therefore, seems to be a gallotannin.

a2. Filtrate from precipitate by subacetate of lead.—The lead was precipitated by hydrosulphuric acid, the nitrate boiled to free from H2S; concentrated and divided into several portions:

1. Acid reaction (from the acetic acid of the lead), mercurio-potassic iodide gave no precipitate; absence of alkaloids.

2. Solution of iodine in potassium iodide; no precipitate; absence of alkaloids.

3. Reduces Fehling's solution without heating; glucose.

4. Evaporated to dryness, the residue had a sweet taste and a somewhat aromatic odor; was soluble in water and alcohol and consisted of two portions, one soluble in a mixture of alcohol and ether (3 to 1), the other insoluble in this menstruum. Both reduced Fehling's solution without the aid of heat and were considered to be "extractive" matter and glucose.

b. Insoluble in water.

b1. Soluble in dilute sulphuric acid.—Coloring matter only; soluble when heated, deposited upon cooling. Negative reactions for glucosides and alkaloides.

b2. Insoluble in dilute sulphuric acid.—Entirely soluble in dilute ammonic hydrate, reprecipitated upon the addition of an acid. This was considered to be an acid resin; it was thoroughly washed and its characteristics noted as follows: Blackish-brown color, brittle, lustrous, opaque in mass, translucent in scales. Odor and taste similar to that of parched coffee; concentrated alcoholic solution has an acid reaction. Insoluble in cold water, ether, benzol and dilute acids; soluble in boiling water (reprecipitated upon cooling), alcohol and alkalies. Concentrated sulphuric acid dissolves it slowly; the solution is dark-brown at first, assuming a pinkish hue around the edges upon standing.. Ferric salts give a black precipitate not unlike that produced by tannin. Its solution in alcohol is wholly precipitated by an alcoholic solution of acetate of lead, the precipitate being of a yellowish color at first, but changes to a dark-brown. The resin is dissipated at a red heat, and when boiled with dilute sulphuric acid, the solution treated with barium carbonate to get rid of the acid, the resulting solution does not reduce Fehling's solution—proving that the substance is not a glucoside.


c. Soluble in water.

c1. Precipitate by subacetate of lead.—Coloring matter only.

c2. Filtrate from precipitate by subacetate of lead.—The excess of lead was precipitated by hydrosulphuric acid, the filtrate boiled, divided into three portions, two of which were tested for alkaloids and glucosides with negative results. The third, portion was evaporated to dry-ness. A crystalline substance of an amber color remained, which, upon analyzing proved to be sodium and potassium salts together with a little organic matter.

d. Insoluble in water.

d1. Soluble in dilute sulphuric acid.—Coloring matter only.

d2. Insoluble in dilute sulphuric acid.—A. small amount of "extractives" and color substances remained.

The drug previously exhausted with benzol and alcohol was exhausted with distilled water. An aliquot part of the aqueous solution was evaporated to dryness and the per cent. extracted by water estimated, which amounted to 4.85. The reserved solution yielded, with alcohol, a gummy precipitate which, with ammonic oxalate, was found to contain calcium. Coloring matter was also extracted by water.

The drug remaining after the above treatment was free from odor and taste, so it was not thought necessary to carry the analysis further.

A decoction of the fresh bark gave a blue reaction with solution of iodine in potassic iodide, indicating the presence of starch. The absence of starch granules in the microscopical sections is due to the fact that the bark from which they were made was previously repeatedly boiled with water to clear the tissues.

The bark treated with solution of potassic carbonate (to extract the organic acids) yielded an extract containing an oxalate, but free from malates and tartrates.

The fresh bark, when distilled with water, yielded a volatile oil, which, when first distilled has a disgusting odor resembling very much the odor of bed-bugs, but when the distillate is treated with ether, the ethereal solution allowed to evaporate, the oil remaining left in contact with the air for twenty-four hours, it acquires a pleasant odor, distinct in itself.

1. Moisture: 6.95 per cent.
2. Ash: 13.85 per cent. Sol. in H2O. 15.967 per cent. (K and Na together with the radicals of H2SO4, HCl and H3PO4).
Insol. in H2O. Sol. in HCl. 74.007 per cent. (Al, Ca and a trace of Na with radical of H3PO4).
Insol. in H2O and HCl. Sol. in NaOH. 9.025 per cent. (Silica).
3. Benzol extract: 6.36 per cent. Consisting of volatile and fixed oils, resin, wax and butyric acid.
4. Alcoholic extract: 23.87 per cent. Tannin, glucose, an acid resin, "extractive" and coloring matter.
5. Cold water extract: 4.85 per cent. Gum and coloring matter.
6. Decoction: Starch, etc.
7. Potassic carbonate extract: Oxalates, etc.
8. Distillation with water: Volatile oil.

Medical Action and Uses.—Rhus aromatica was introduced to the profession at large in the spring of 1878 by Dr. J. F. McClanahan, of Boonville, Mo., as "a remedy highly useful in the treatment of diabetes, enuresis, haematuria, uterine hemorrhages, menorrhagia and other excessive discharges, accompanied by a relaxed condition of the uterus, diarrhoea and other atonic diseases of the bowels." Drs. John Gray and F. McClanahan had used this remedy extensively in their practice in such cases as above mentioned with marked benefit, but left it for the son to bring before the public. Since its introduction many physicians have tested its virtues, and their statements corroborate those of the discoverers. That it is an efficacious remedy in the treatment of enuresis there can be no doubt, for the author of this essay has seen it tried with success in several cases. A tincture containing the oleoresin, acid resin, gallotannin and extractives of the crude drug and representing 4 troy-ounces to a pint of stronger alcohol may be made by macerating the ground drug in the menstruum for seven days, with frequent agitation and then percolating until one pint of tincture is obtained. It is obvious that preparations of Rhus aromatica should not be mixed with solutions containing salts of iron.

The dose of the powdered drug is from 20 to 60 grain (gm. ⅓ to 4.0); the fluid extract 5 to 40 drops (gm. .3 to 2.5); the tincture 20 drops to a teaspoonful (gm. 1.0 to 4.0) given in water and repeated as often as necessary. As a topical remedy to control hemorrhage a decoction of the bark will be found efficacious.

In conclusion, I desire to state that the process followed in the chemical investigation was the one reported by Mr. Henry B. Parsons in the "American Journal of Pharmacy," 1880, p. 210; the analysis was made in the laboratory of the Philadelphia College of Pharmacy, under the supervision of Prof. J. M. Maisch and Dr. F. B. Power, and I am indebted to Mr. F. L. Slocum for the use his of microscope, with which I have been enabled to produce the drawings of the sections.

The American Journal of Pharmacy, Vol. 53, 1881, was edited by John M. Maisch.