Spec Plant Willd. iii. 871. Cl. 17. Ord.3. Diadelphia Octandria. Nat. ord. Polygaleae. G. 1313. Calyx five-leaved, with two of the leaflets wing-shaped, and coloured. Legume obcordate, two celled. * * * Beardless; herbaceous, with a simple stem. Species 67. P. Senega. Seneka root. Med. Bot. 3d edit. 452.

t. 162. Amain. Acad. iii. 124. Pursh. iii. p. 464. Officinal. Senegae radix, Zand. POLYGALAe Senegae radix,

Edin. Dub. Seneka root.

Syn. Polygale de Virginie (F.), Senegawurzel (G.), Poligala Virginiana (I.).

This plant is a perennial native of North America, flowering in June.2 The root is woody, branched, contorted, about half an inch thick, and covered with ash-coloured bark; it sends up several stems a foot in height, erect, slender, round, smooth, and of a dark reddish colour. The leaves are petio-late, alternate, lanceolate, acute, and pale green : the flowers are in loose, terminal spikes, small, white, and papilionaceous, with the calyx divided into three narrow, persistent segments; the fruit is an inversely cordate capsule, containing several small seeds.

The root is brought from Virginia in bales, each containing from two to four hundred weight.

Qualities.-Seneka root is inodorous : the taste is at first sweetish and nauseous; but after being chewed for less than a minute, becomes pungent and hot, producing a very peculiar tingling sensation in the fauces. These qualities reside in the bark; which, on the dried root, is white within, and covered with a brownish grey, corrugated, transversely cracked cuticle: the central part is white, but woody and inert: alcohol extracts the whole of its active matter, which is precipitated from the tincture by the addition of water; and the ethereal tincture deposits a pellicle of resin, but no extractive. From six ounces of the root Peschier separated 100 grains of a peculiar alkaline principle, which he has named Polygalina, united with a new acid, which he has denominated the Polygalinic; and this salt he supposes is the active principle of seneka root.1 Hot water extracts its virtues partially only; but in a sufficient degree to exert its influence on the animal system.

1 Muschenbroek. It was first cultivated in England by Mr. F. Miller, in 1759.

Medical properties and uses.-This root is a stimulating expectorant and diuretic; and, in large doses, emetic and cathartic: it increases absorption, and consequently augments the natural excretions, particularly that of urine; and frequently occasions a copious ptyalism. It was introduced to the notice of physicians by Dr. Tennant, who, having discovered that it was the antidote employed by the Senagaro Indians against the bite of the rattlesnake, and reasoning from the effects of the poison, and of the remedy in removing these, was induced to try it in pneumonic affections, and found it useful. On account of its stimulant properties, however, it can be employed in these complaints only after the resolution of the inflammation by bleeding and evacuations. It proves more directly useful in humoral asthma, chronic catarrh, and some kinds of dropsy; and has been found very efficacious in rheumatic and scrofulous ophthalmia, even after pus had appeared in the anterior chamber.2 The extract of it combined with carbonate of ammonia has been found by Dr. Brandreath, of Liverpool, to be efficacious in some cases of lethargy; and in America the decoction given in divided doses, at short intervals, till it vomit or purge, has been employed with seeming success in croup 3: it has also been used as a stimulant gargle in the same disease.

' It may be administered either in the form of powder or decoction, combined with aromatics, opium, or camphor, which check its nauseating qualities. Madeira wine, where it can be ordered, may be used to cover the taste of the powder. The dose in substance is from grs. x. to 3j., repeated every three or four hours.

Cartheuser recommended the root of this plant in incipient cataract. Dr. Schmalze of Dresden found it very useful in all inflammatory affections of the eye which are followed by a morbid secretion from that organ, rheumatic ophthalmia, catarrhal ophthalmia, erysipelas of the eye, different species of iritis, with the exception of those arising from syphilis. It is contra-indicated in scrofulous affections, at least those accompanied with morbid exudations of the cornea. It is very salutary in hypopyon, at the moment when the disease is passing from the inflammatory to a state of exudation. It is given in pills containing soap, and may be carried to one grain and a half per day; the evident effect is the production of fluid stools without colic.

1 Pharmacopoeia Batava, etc. editione de Joanne Frid, Neimann, Lipsiae, 1824.

2 Med. Repository, vol. iv. (New Series), p. 56.

3 London Medical Review and Magazine, iii; 426.

Officinal preparation.-Decoctum Senegae, L. E.