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Phytolacca decandra. Poke.

Botanical name:

[image:28262 align=left hspace=1]FROM the testimony of different writers it appears, that the Phytolacca decandra is an inhabitant not only of North America, but likewise of the south of Europe from Portugal to Greece, and also of the Barbary states in Africa. Its origin is probably American, since I find that it was so considered in the time of Parkinson, who in his Theatrum Botanicum, published in 1640, denominates it "Solanum magnum Virginianum rubrum." This is one of the oldest accounts I find of it. Plukenet conjectures it may be the Cuechiliz tomatl of Hernandez, but the description, like most others of that loose and superficial writer, are more promotive of obscurity than of knowledge, and it is not easy to draw from it any satisfactory evidence as to its Mexican origin.

[Note D.] ["De Cuechyliztomatl, seu Tomatl sonalis.
Genus est Solani Tonchichi forma et viribus simile, sed foliis paulisper undulatis, et fructu acinoso racematimnue dependente, &c." Hernandez, ii. 12.]

In the autumnal months no plant among us is more remarkable than the Phytolacca for its large size, and the fine colour of its clusters of berries. Its most general appellation is Poke, an abbreviation, perhaps, of Pocan, the name by which it was known in Virginia a century ago. In New England it is more frequently called Garget, Cocum, Jalap and Pigeon berries.

Jussieu has arranged this genus among his Atriplices, and Linnaeus with the Oleraceae.

The number of its stems and styles, place it in the class Decandria and order Decagynia. Its generic character consists in having no calyx, a corolla of five petals, and its berries superior with ten cells and ten seeds. The species decandra is the only one which strictly agrees with its class and order, and is known by having ovate leaves, acute at both ends, and its flowers with ten stamens and styles.

The root of this plant is of large size, frequently exceeding a man's leg in thickness, and is usually divided into two or three principal branches. Its substance is fleshy and fibrous, and easily cut or broken. Internally it is distinctly marked with concentric rings of considerable thickness, while its outer surface is covered with a very thin brownish bark, which seems to be little more than a cuticle. The stalks, which are annual, frequently grow to the height of six, and even nine feet. They are round, smooth, and very much branched. When young, their usual colour is green, but in most plants, after the berries have ripened, they are of a fine purple. The leaves are scattered, petioled, ovate-oblong, smooth on both sides, ribbed underneath, entire, acute. The flowers grow on long pedunculated racemes opposite to leaves. Peduncles nearly smooth, angular, ascending. Pedicels divaricated, sometimes branched, green, white, or purple, furnished with a small linear bracte at base, and two others in the middle. Calyx none. Corolla resembling a calyx, whitish, consisting of five round-ovate, concave, incurving petals. Stamens ten, rather shorter than the petals, with white, roundish, two lobed anthers. Germ greenish, round, depressed, ten furrowed. Styles ten, short, recurved. The flowers are succeeded by long clusters of dark purple berries, almost black, depressed or flattened, and marked with ten furrows on the sides.

The dried root is light coloured and spongy, with a mild and somewhat sweetish taste. A part of it is soluble both in water and alcohol, and neither of these substances renders turbid the solution in the other, unless the solution has been inspissatedby long boiling. The soluble portion appears neither resinous nor mucous. It approaches most nearly to extractive, but has characters somewhat peculiar to itself. A decoction of the root procured by boiling for ten minutes in distilled water, exhibited after filtration the following results. It was transparent, nearly colourless, and did not alter litmus. It gave no precipitate with the sulphuric, nitric, muriatic, oxyinuriatic, and acetous acids. It gave no precipitate with the sulphate of iron, but formed a copious one with the nitrates of mercury and silver, and the acetate of lead. Muriate of tin produced no effect at first, but after standing, a light precipitate took place. Pearl ash, lime water, and muriate of barytes rendered the solution turbid. Acetate of barytes occasioned no change. Oxymuriate of lime formed an immediate precipitate.

The cold infusion exhibited nearly the same results as the decoction. The alcoholic solution underwent no change from muriate of tin, but threw down a dense precipitate with nitrate of mercury.

From the above experiments it appears, that the soluble principle of the Phytolacca differs from common vegetable extractive, as defined by the chemists, in several respects, particularly in not being thrown down by the oxymuriatic or other mineral acids, and in being but partially affected by muriate of tin.

In the Annales de Chimie, vol. lxxii, is a memoir on the Chemical properties of the Phytolacca decandra by M. Braconnot. His experiments indicate the presence of an unusual quantity of vegetable alkali in this plant. He found that the ashes, procured by incinerating the stalks, afforded nearly 67 per cent. of dried alkaline carbonate, and 42 per cent. of pure caustic potash. This alkali in the plant is neutralized by an acid having considerable affinity to the malic, but with a few shades of difference. With lime and lead malic acid forms flocculent precipitates, very easily soluble in distilled vinegar, but those with the phytolaccic acid are insoluble. M. Braconnot thinks this acid may probably be a mean between the malic and oxalic acids, or an oxygenized malic acid.

The same memoir contains an examination of the colouring matter in the berries of the Phytolacca. The juice of these berries is of a very fine, bright purple colour, but this colour is extremely fugacious and disappears in a short time from cloth or paper that has been tinged with it. A few drops of lime water added to this purple juice change it to a yellow colour, but the smallest quantity of acid is sufficient to restore its purple hue. Exposure to the air or large dilutions is sufficient to restore the original purple.

M. Braconnot considers the yellow liquor produced by the juice of these berries and lime water as one of the most delicate tests of the presence of acid. Into two glasses he put equal quantities of the juice made yellow and of an infusion of litmus of equal depth of colour. More than sixty drops of a very weak acid were required to redden the infusion of litmus, but less than fifteen restored the purple colour of the Phytolacca. Hence it follows, that the yellow liquor is four times as sensible to the presence of acid, as the infusion of litmus. It however requires to be used immediately after it is prepared, since a few hours cause a spontaneous change in it, which begins with a precipitate, and ends with a deprivation of colour.

The effects produced on this purple colour by other reagents were as follows. Pure alkalis gave it a yellow colour. Alkaline subcarbonates a violet, that fades and becomes yellow by standing. Weak acids no perceptible change. Dilute oxymuriatic acid a complete deprivation of colour with white flocculi. Alum nothing at first, but after some days, a very light red precipitate. Muriate of lime no change. Muriate of tin a red sediment inclining to lilac, leaving the fluid colourless. Nitrate of lead a precipitate of the colour of wine lees. Super oxided sulphate of iron, a dirty violet.

Many of the above experiments I have repeated, and added others. The yellow colour produced by the alkalis borders on green. Pure strontian produces the same change as potash and lime. Pure barytes wholly discharges the colour on standing a short time. Acetate of lead forms a scarlet precipitate, leaving the liquid nearly colourless.

The purple colour that tinges the cuticle of the stalks of the Phytolacca is stated in the above memoir, to be of the same nature as that in the berries, and to afford the same results.

The taste of the berries is sweetish and nauseous, leaving behind a very slight sense of acrimony. M. Braconnot, found that at a moderate temperature, the juice underwent the vinous fermentation, and yielded alcohol by distillation. Dr. Shultz procured from half a bushel of the berries six pints of spirit sufficiently strong to take fire and burn with readiness.

In its medicinal properties the root of the Phytolacca decandra approaches nearer to ipecacuanha than any American vegetable, I have hitherto examined. From abundant experience, the result of many trials made in Dispensary practice, I am satisfied that, when properly prepared, it operates in the same doses and with the same certainty, as the South American emetic. Ten grains of the powder will rarely remain on the stomach, and twenty or thirty produce a powerful operation, by emesis and generally by catharsis. In its mode of operation, this medicine has some peculiarities, a part of which are favorable, others disadvantageous. Its advantages are, that it operates with ease, and seldom occasions pain or cramp. Its disadvantages are,
1. That it is slow in its effects, frequently not beginning to operate until an hour, and sometimes two hours after it is taken.
2. That it continues to operate for a greater length of time than is usual for emetics, although as far as I have been able to observe, it is readily checked by an opiate.
These disadvantages however are not constant. I have repeatedly known it commence operating in fifteen minutes, and cease after four or five ejections. The representations of patients as to any unpleasant feelings under its effects, are not greater than we should naturally expect, when it is recollected, that no emetic is altogether comfortable in its operation. Dr. Fisher of Beverly [Letter dated November, 1815.] informs me that whenever he has used the Phytolacca, it has performed its duty as an emetic perfectly well, and that in one patient, a female of irritable stomach, in whom previous emetics had always excited severe spasms, ten grains of the Phytolacca operated effectually, and no spasm followed.

I have sometimes observed slight narcotic symptoms during the operation of Phytolacca, particularly vertigo. But others have not always met with this symptom. Dr. George Hayward of this town, who has had much experience with this medicine, the results of which were communicated to the Linnaean society, and afterwards published in the New England Journal, October 1817, states that in doses of a scruple, he never noticed any dizziness, or stupor from it, although he had always been particular in his inquiries to know if any such symptoms took place. The above dose was administered by him in nearly thirty cases, in all of which, except in one case, it operated as an emetic and cathartic, usually three or four times, thoroughly, though not severely, generally commencing its operation on the stomach in an hour, and rarely continuing longer than four. He found it to excite little or no nausea previous to its operation, and though it made a powerful impression on the system, it never produced any disagreeable or unusual symptoms.

Dr. Hayward also made trial of the powder of the leaves, which he found to possess the same properties with that of the root, but to be less effectual and less certain in its operation. He also prepared a tincture, decoction, and wine of the root; but all these were inferior to the medicine in substance, being less certain in their effect, and sometimes giving rise to troublesome symptoms.

Dr. Shultz of Pennsylvania, author of an inaugural dissertation on the Phytolacca decandra, gave the expressed juice of the leaves, berries, and roots, in considerable quantity to animals. It operated by emesis and catharsis, attended with drowsiness. The juice of the root was most active. He also gave to a dog two ounces of the spiritous liquor distilled from the berries. It occasioned nausea and drowsiness, with slight spasmodic motions, but no vomiting.

In the same dissertation, Dr. Shultz refers to several instances of persons who had incautiously eaten large quantities of the root through mistake. Its effects were violent vomiting and purging, prostration of strength, and in some instances convulsions.

The Phytolacca has had some reputation in the treatment of rheumatism. Dr. Griffits, formerly a professor in the University of Pennsylvania, found it of great use in Syphilitic rheumatism. Dr. Hayward however states, that he derived no advantage from its employment in rheumatic affections.

The young shoots of this vegetable are destitute of medicinal qualities, and are eaten in the spring in some parts of the United States, as substitutes for asparagus. At this time the succus proprius or returning juice of the plant is not yet formed by exposure of the sap to the atmospheric air, in the leaves. The ripe berries are less noxious than the green, and are devoured by several species of birds. In Portugal and in France they were formerly employed to improve the colour of red wines, until the interference of government became necessary to put a stop to the practice.

The external application of Phytolacca has been found useful in a variety of cases, by its action as a local stimulant. The ointment and extract have commonly been employed for this purpose. These preparations usually excite a sense of heat and smarting on being first applied. I have cured cases of psora with the ointment, and Dr. Hayward states, that he found it successful in cases where sulphur had failed. A case of tinia capitis of twelve years' standing, which had resisted various kinds of treatment, was also cured by this application.

The Phytolacca is one of those vegetables which has had its temporary reputation for the cure of cancer. For this purpose it has been resorted to in various parts of the world, and many men of science have been convicts to its efficacy, among whom were Dr. Colden and Dr. Franklin of our country.

[Note E.] ["I am heartily glad to hear more instances of the success of the Poke weed in the cure of cancer. You will deserve highly of mankind for the communication. But I find in Boston they are at a loss to know the right plant, some asserting it is what they call Mechoacan, others other things. In one of their late papers it is publicly requested that a perfect decription may be given of the plant, its places of growth, &c. I have mislaid the paper, or would send it to you. I thought you had described it pretty fully." Letter from Dr. Franklin to Dr. Colden.
"I apprehend that our poke-weed is what botanists term phytolacca. This plant bears berries as large as peas. The skin is black, but it contains a crimson juice. It is this juice thickened by evaporation in the sun which was employed. It caused great pain, but some persons were said to have been cured. I am not quite certain of the facts; all that I know is that Dr. Colden had a good opinion of the remedy." Letter from Dr. Franklin to M. Dubourg.]

But like other vegetable specifics for cancer, it owes its character to an imperfect discrimination of that disease, and a misapplication of the name. All that can be strictly inferred from the various accounts we have had on this subject, is, that the plant has often proved useful in malignant ulcers by its stimulating and almost escharotic effects, frequently producing an eschar, and thus altering the condition of the ulcerated surface.

For internal use no preparation of the Phytolacca is to be preferred to the powder, of which from ten to fifteen grains is often a sufficient emetic.

The root should be dug late in autumn or during the winter. It should be cut in transverse slices and dried. After being pulverized, it should be kept in close stopped phials. The stock should be annually renewed, as its activity is impaired by age.

Botanical References.

Phytolacca decandra, Linnaeus, sp. pl.
Aiton, Hort. Kew. ii 122.
Botanical Magazine, t. 931.
Michaux, Fl. Amer. i. 278.
Pursh. i. 324.
Phytolacca vulgaris, Dillenius, Hort. Elth. t. 239.
P. Americana
Boerhaave, Hort. Lug. ii. 70.
Solanum racemosum Americanum, Raius, Hist. 662.
Plukenet, Phyt. t. 225. f. 3.
Solanum magnum Virginianum rubrum, Parkinson, Theatrum, 347.
Blitum Americanum, Muntingius, Phyt. cur. t. 212.

Medical References.

Murray, appar. med. iv. 335.
Kalm, travels in N. Amer. i 197.
Graffenreid, Mem. Berne, iii. 185.
Schoepf. 71.
Browne, Hist. Jamaica, 232.
Amoen. Acad. iv.
Miller, Dict under the name.
Sprogel. Diss. cir. ven. 24.
Beckman, comment. Gotting. 1779, 74.
Allioni, Flor. Ped. ii. 132.
Franklin, works, vol. i.
Cutler, Mem. Amer. Acad. i. 447.
Rush, i. 259.
Thacher, Disp. 300.
Shulz, Inaugural thesis.
Hayward, N. Engl. Journal, vi.


American Medical Botany, 1817-1821, was written by Jacob Bigelow, M. D.



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