part 30

(1876).

[329] _Mem. de la R. Acad. med. de Madrid_, i. (1797) 349—366.

[330] _Medicinal and Chirurgical Review_, Lond., xiii. (1806) ccxlvi.; also Reece, _Dict. of Domest. Med._, 1808.

=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.).

[331] See art. Kino.

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_.

[332] _Etudes sur le Genre Krameria_ (thèse), Paris, 1868. 83.

[333] Gmelin, _Chemistry_, xiii. (1859) 358.

[334] See Vogl’s Paper on it in Pringsheim, _Jahrbücher für wissenschaftliche Botanik_, ix. (1874) 277-285.

[335] For further particulars, see Flückiger, _Pharm. Journ._, July 30, 1870. 84.

[336] _Syst. Mat. Med. Bras._, 1843. 51; Langgaard, _Diccionario de Medicina_, Rio de Janeiro, iii. (1865) 384.—Krameria argentea is figured in _Flora Brasiliensis_, Fascicul. 63 (1874, pg. 71) tab. 28.

_=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]

[337] Hanbury, _Origin of Savanilla Rhatany_, in _Pharm. Journ._ vi. (1865) 460.—Also _Science Papers_, 333.—In that paper I referred the drug to a variety of _Kr. Ixina_ which M. Cotton has shown to differ in no respect from St. Hilaire’s _Kr. tomentosa_, a conclusion in which, after careful re-examination of specimens, I fully agree.—D. H.

Fig. of _Kr. Ixina_ in Bentley and Trimen, _Med. Pl._