POLYGALEÆ.
RADIX SENEGÆ.
Radix Senekæ; Senega or Seneka Root; F. Racine de Polygala de Virginie; G. Senegawurzel.
Botanical Origin—Polygala Senega L., a perennial plant with slender ascending stems 6 to 12 inches high, and spikes of dull white flowers resembling in form those of the Common Milkwort of Britain. It is found in British America as far north as the river Saskatchewan, and in the United States from New England to Wisconsin, Kentucky, Tennessee, Virginia and the upper parts of North Carolina, as well as in Georgia and Texas, not in the Rocky Mountains.
The plant, which frequents rocky open woods and plains, has become somewhat scarce in the Atlantic states, and as a drug is now chiefly collected in the west, the plant growing profusely in Iowa and Minnesota, west of New York.
History—The employment of this root among the Seneca Indians as a remedy for the bite of the rattlesnake attracted the notice of Tennent, a Scotch physician in Virginia; and from the good effects he witnessed he concluded that it might be administered with advantage in pleurisy and peripneumonia. The result of numerous trials made in the years 1734 and 1735 proved the utility of the drug in these complaints, and Tennent communicated his observations to the celebrated Dr. Mead of London in the form of an epistle, afterwards published together with an engraving of the plant, then called the Seneca Rattlesnake Root.[325] Tennent’s practice was to administer the root in powder or as a strong decoction, or more often infused in wine. The new drug was favourably received in Europe, and its virtues discussed in numerous theses and dissertations, one written in 1749 being by Linnæus.[326]
Description—Senega root is developed at its upper end into a knotty crown, in old roots as much as an inch in diameter, from which spring the numerous wiry aerial stems, beset at the base with scaly rudimentary leaves often of a purplish hue. Below the crown is a simple tap-root ²/₁₀ to ³/₁₀ of an inch thick, of contorted or somewhat spiral form, which usually soon divides into 2 or 3 spreading branches and smaller filiform rootlets.
The bark is light yellowish-grey, translucent, horny, shrivelled, knotted and partially annulated. Very frequently a keel-shaped ridge occurs, running like a shrunken sinew through the principal root; it has no connexion with the wood, but originates in a one-sided development of the liber-tissue. The bark encloses a pure, white woody column about as thick as itself. After the root has been macerated in water the bark is easily peeled off, and the peculiar structure of the wood can then be studied. The latter immediately below the crown is a cylindrical cord, cleft however by numerous, fine, longitudinal fissures. Lower down these fissures increase in an irregular manner, causing a very abnormal development of the wood. Transverse sections of a root therefore differ greatly, the circular wood portion being either penetrated by clefts or wide notches, or one-half or even more is altogether wanting, the space where wood should exist being in each case filled up by uniform parenchymatous tissue.
Senega root has a short brittle fracture, a peculiar rancid odour, and a very acrid and sourish taste. When handled it disperses in irritating dust.
Microscopic Structure—The woody part is built up of dotted vessels surrounded by short porous ligneous cells; the medullary rays consist of one or two rows of the usual small cells. There is no pith in the centre of the root. The clefts and notches are filled up with an uniform tissue passing into the primary cortical tissue without a distinct liber; the large cells of this tissue are spirally striated. In the keel-shaped rider the proper liber rays may be distinguished from the medullary rays. The former are made up of a soft tissue, hence the cortical part of the root breaks short together with the wood.
Neither starch granules nor crystals of oxalate of calcium are present in this root; the chief contents of its tissue are albuminoid granules and drops of fatty oil.
Chemical Composition—The substance to which the drug owes its irritating taste was distinguished by the name of Senegin by Gehlen as early as 1804, and is probably the same as the Polygalic Acid of Quevenne (1836) and of Procter (1859). Christophsohn (1874) extracted it by means of boiling water, evaporated the solution and exhausted the residue with boiling alcohol (0·853 sp. gr.). The liquid after a day or two, deposits the crude senegin, which is to be washed with alcohol (0·813 sp. gr.), and again dissolved in water, from which it is precipitated by a large excess of hydrate of baryum. The barytic compound, dissolved in water, is decomposed by carbonic acid, by which carbonate of baryum is separated, senegin remaining in solution. It is lastly to be precipitated by alcohol. It is amorphous, insoluble in ether and in cold water; it forms with boiling water a frothing solution. Like saponin, to which it is very closely allied, it excites violent sneezing.
Dilute inorganic acids added to a warm solution of senegin throw down a flocculent jelly of Sapogenin, the liquid retaining in solution uncrystallizable sugar. Alkalis give rise to the same decomposition; but it is difficult to split up the senegin completely, and hence the formulas given for this process are doubtful. Even the formula of senegin itself is not definitely settled. According to Christophsohn, the root yields about 2 per cent. of this substance; according to earlier authorities, who doubtless had it less pure, a much larger proportion. From Schneider’s investigations (1875) it would appear that the rootlets are richest in senegin.
Senega root contains a little volatile oil, traces of resin, also gum, salts of malic acid, yellow colouring matter, and sugar (7 per cent. according to Rebling, 1855). The Virginic Acid said by Quevenne to be contained in it, and the bitter substance Isolusin mentioned by Peschier, are doubtful bodies.
Uses—Senega is prescribed as a stimulating expectorant and diuretic, useful in pneumonia, asthma and rheumatism. It is much esteemed in America.
Adulteration—The drug is not liable to be wilfully falsified, but through careless collecting there is occasionally a slight admixture of other roots. One of these is American Ginseng (Panax quinquefolium L.) a spindle-shaped root which may be found here and there both in senega and serpentaria. The rhizome of Cypripedium pubescens Willd. has also been noticed; it cannot be confounded with that of Polygala Senega. The same may be said with regard to the rhizome of Cynanchum Vincetoxicum R. Brown (Asclepias L., Vincetoxicum officinale Mönch).
RADIX KRAMERIÆ.
Radix Ratanhiæ, Rhatanhiæ v. Rathaniæ; Rhatany or Rhatania Root, Peruvian or Payta Rhatany; F. Racine de Ratanhia; G. Ratanhiawurzel.[327]
Botanical Origin—Krameriæ triandra Ruiz et Pav., a small woody shrub with an upright stem scarcely a foot high and thick decumbent branches 2 to 3 feet long.[328] It delights in the barren sandy declivities of the Bolivian and Peruvian Cordilleras at 3000 to 8000 feet above the sea-level, often occurring in great abundance and adorning the ground with its red star-like flowers and silver-grey foliage.
The root is gathered chiefly to the north, north-east, and east of Lima, as at Caxatambo, Huanuco, Tarma, Jauja, Huarochiri and Canta; occasionally on the high lands about lake Titicaca. It appears likewise to be collected in the northern part of Peru, since the drug is now frequently shipped from Payta.
History—Hipolito Ruiz,[329] the Spanish botanist, observed in 1784 that the women of Huanuco and Lima were in the habit of using for the preservation of their teeth a root which he recognized as that of Krameria triandra, a plant discovered by himself in 1779. On his return to Europe he obtained admission for this root into Spain in 1796, whence it was gradually introduced into other countries of Europe.
The first supplies which reached England formed part of the cargo of a Spanish prize, and were sold in the London drug sales at the commencement of the present century. Some fell into the hands of Dr. Reece who recommended it to the profession.[330]
About 20 years ago there appeared in the European market some other kinds of rhatany previously unknown: of these the more important are noticed at pp. 81, 82.
Description—The root which attains a considerable size in proportion to the aerial part of the shrub, consists of a short thick crown, sometimes much knotted and as large as a man’s fist. This ramifies beneath the soil even more than above, throwing out an abundance of branching, woody roots (frequently horizontal) some feet long and ¼ to ½ an inch thick. These long roots used formerly to be found in commerce; but of late years rhatany has consisted in large proportion of the more woody central part of the root with short stumpy branches, which from their broken and bruised appearance have evidently been extracted with difficulty from a hard soil.
The bark which is scaly and rugged, and ⅒ to ¹/₂₀ of an inch in thickness, is of a dark reddish-brown. It consists of a loose cracked cork-layer, mostly smooth in the smaller roots, covering a bright brown-red inner bark, which adheres though not very firmly to a brownish yellow wood. The bark is rather tough, breaking with a fibrous fracture. The wood is dense, without pith, but marked with thin vessels arranged in concentric rings, and with still thinner, dark medullary rays. The taste of the bark is purely astringent; the wood is almost tasteless; neither possesses any distinctive odour.
Kr. cistoidea Hook, a plant scarcely to be distinguished from Kr. triandra, affords in Chili a rhatany very much like that of Peru. Its root was contributed to the Paris Exhibition of 1867.
Microscopic Structure—The chief portion of the bark is formed of liber, which in transverse section exhibits numerous bundles of yellow fibres separated by parenchymatous tissue and traversed by narrow brown medullary rays. The small layer of the primary bark is made up of large cells, the surface of the root of large suberous cells imbued with red matter. The latter also occurs in the inner cortical tissue, and ought to be removed by means of ammonia in order to get a clear idea of the structure. Many of the parenchymatous cells are loaded with starch granules; oxalate of calcium occurs in the neighbourhood of the liber bundles. The woody portion exhibits no structure of particular interest.
Chemical Composition—Wittstein (1854) found in the bark of rhatany (the only part of the drug having active properties) about 20 per cent. of a form of tannin called Ratanhia-tannic Acid, closely related to catechu-tannic acid. It is an amorphous powder, the solution of which is not affected by emetic tartar, but yields with ferric chloride a dark greenish precipitate. By distillation Eissfeldt (1854) obtained pyrocatechin as a product of the decomposition of ratanhia-tannic acid. The latter is also decomposed by dilute acids which convert it into crystallizable sugar and Ratanhia-red, a substance nearly insoluble in water, also occurring in abundance ready formed in the bark.
Grabowski (1867) showed that by fusing ratanhia-red with caustic potash, protocatechuic acid and phloroglucin[331] are obtained. Ratanhia-red has the composition C₂₆H₂₂O₁₁, the same, according to Grabowski, as an analogous product of the decomposition of the peculiar tannic acid occurring (as shown by Rochleder in 1866) in the horse-chestnut. The same red substance may also be obtained, as stated by Rembold (1868), from the tannic acid of the root of tormentil (Potentilla Tormentilla L.).
As to rhatany root, Wittstein also found it to contain wax, gum and uncrystallizable sugar (even in the wood! according to Cotton[332]). Cotton further pointed out the presence in very minute quantity of an odorous, volatile, solid body, obtainable by means of ether or bisulphide of carbon; it occurs in a somewhat more considerable amount in the other sorts of rhatany. The root contains no gallic acid.
A dry extract of rhatany resembling kino used formerly to be imported from South America, but how and where manufactured we know not. It is however of some interest as containing a crystalline body which Wittstein who discovered it (1854) regards as Tyrosin, C₉H₁₁O₃, previously supposed to be exclusively of animal origin.[333] Städeler and Ruge (1862) assigned to it a slightly different composition, C₁₀H₁₃NO₃, and gave it the name of Ratanhin. It dissolves in hot water which is acidulated by a little nitric acid; the solution on boiling turns red, blue, and lastly green, and becomes at the same time fluorescent. Kreitmair (1875) extracted 0·7 per cent, of ratanhin from an old specimen of commercial extract of rhatany; but he did not succeed in obtaining it from other specimens. He also showed that ratanhin is not a constituent of the roots of Krameria. The same substance has been abundantly found by Gintl (1868) in the natural exudation called Resina d’Angelim pedra[334] which is met with in the alburnum of Ferreirea spectabilis Allem., a large Brazilian tree of the order Leguminosæ (tribe Sophoreæ). Peckolt, who first extracted it, named it Angelin; it forms colourless, neutral crystals yielding compounds both with alkalis and acids, which have been investigated by Gintl in 1869 and 1870.
Uses—Rhatany is a valuable astringent, but is not much employed in Great Britain.
Other sorts of Rhatany—Of the 20 to 25 other species of Krameria, all of them belonging to America, several have astringent roots which have been collected and used in the place of the rhatany of Peru. The most important of these drugs is that known as—
Para Rhatany,—so called from having been shipped from Pará in Brazil. Berg who described it in 1865 termed it Brazilian Rhatany, Cotton in 1868, Ratanhia des Antilles. It is a drug nearly resembling the following, but of a darker and less purple hue; it is also in longer sticks which are remarkably flexible, and covered with a thick bark having numerous transverse cracks.[335] It is apparently derived from the Krameria argentea of Martius,[336] the root of which is collected in the dry districts of the provinces of Bahia and Minas Geraes, that plant growing throughout north-eastern Brazil. It is also called Rhatany from Ceará.
Savanilla or New Granada Rhatany. The plant yielding it is Krameria tomentosa St. Hil. (Kr. Ixina var. β granatensis Triana, Kr. grandifolia Berg), a shrub 4 to 6 feet high covering large arid tracts in the valley of Jiron between Pamplona and the Magdalena in New Granada, in which locality the collection of the root was observed by Weir in 1864.[337] According to Triana it also grows at Socorro, south of Jiron. The same plant is found near Santa Marta and Rio Hacha in north-eastern New Granada, in British Guiana, and in the Brazilian provinces of Pernambuco and Goyaz.
The stem or root-crown of Savanilla rhatany is never so knotty and irregular as that of the Peruvian drug, nor are the roots so long or so thick. Separate pieces of root of sinuous form, 4 to 6 inches long and ²/₁₀ to ³/₁₀ of an inch thick are most frequent. The drug is moreover well distinguished by its dull purplish brown colour, its thick smooth bark marked with longitudinal furrows, and here and there with deep transverse cracks, and by the bark not easily splitting off as it does in common rhatany.
The anatomical difference depends chiefly upon the more abundant development of the bark which in thickness is ⅓ to ¼ the diameter of the wood. In Peruvian rhatany the cortical layer attains only ⅙ to ⅛ of the diameter of the woody column. The greater firmness of the suberous coat in Savanilla rhatany is due to its cells being densely filled with colouring matter.
Savanilla rhatany differs from the Peruvian root in its tannic matter. This becomes evident by shaking the powdered root (or bark) with water and iron reduced by hydrogen. The liquid filtered from the Savanilla sort and diluted with distilled water exhibits an intense violet colour, that from Peruvian rhatany a dingy brown; the latter turns light red by alkalis. Thin sections of the Peruvian root assume a greyish hue when moistened with a ferrous salt; Savanilla root by a similar treatment displays the above violet colour. The Savanilla root is richer in soluble matter and from the greater development of its bark may deserve to be preferred for medicinal use.
In the English market, Savanilla root is of less frequent occurrence than that of Pará.
A kind of rhatany attributed to Krameria secundiflora DC., a herbaceous plant of Mexico, Texas and Arkansas, was furnished to Berg in 1854, but has not been in commerce. Its anatomical structure has been described by Berg.[338]