part 26

(1877).

[420] _Observations on the Orayuri or Angustura Bark Tree_,—_Trans. of Medico-Botanical Society_, 1827-29.—Hancock endeavoured to prove his tree distinct from _G. Cusparia_ St. Hil., but Farre and Don who subsequently examined his specimens decided that the two were the same. With the assistance of Prof. Oliver, I also have examined (1871) Hancock’s plant, comparing it with his figure and other specimens, and have arrived at the conclusion that it is untenable as a distinct species.—D. H.

[421] Martiny, _Encyklopädie_, i. (1843) 242.

[422] Brande, _Experiments and Observations on the Angustura Bark_. 1791. 2nd ed. 1793.

[423] _London Med. Journ._ x. (1789) 154.

=Microscopic Structure=—The most striking peculiarity is the great number of oil-cells scattered through the tissue of the bark. They are not much larger than the neighbouring parenchymatous cells, and are loaded with yellowish essential oil or small granules of resin. Numerous other cells contain bundles of needle-shaped crystals of oxalate of calcium or small starch granules. The liber exhibits bundles of yellow fibres, to which the foliaceous fracture of the inner bark is due. The structure of the bark under notice has been very minutely described and figured by Oberlin and Schlagdenhauffen.[424]

=Chemical Composition=—Angostura bark owes its peculiar odour to an essential oil which it was found by Herzog[425] to yield to the extent of ¾ per cent. It is probably a mixture of a hydrocarbon (C₁₀H₁₆) with an oxygenated oil. Its boiling point is 266° C. Oberlin and Schlagdenhauffen obtained 0·19 per cent. of the oil, and found it to be slightly dextrogyre; it assumes a fine red colour when shaken with aqueous ferric chloride, and turns yellow with concentrated sulphuric acid.

[424] _Journ. de Pharm. et de Chimie_, 28 (1877), 226; plates I, II, III. The bark is also figured by Berg, _Anatomischer Atlas_, Tab. 37.

[425] _Archiv d. Pharm._ xcii. (1858) 146.

The bitter taste of the bark is attributed to a substance pointed out in 1833 by Saladin and named _Cusparin_. It is said to be crystalline, neutral, melting at 45° C., soluble in alcohol, sparingly in water, precipitable by tannic acid. The bark is stated to yield it to the extent of 1·3 per cent. Herzog endeavoured to prepare it but without success, nor have Oberlin and Schlagdenhauffen met with it. The latter chemists, on the other hand, isolated an alkaloid _Angosturine_ C₁₀H₄₀NO₁₄. It is in thin prisms, melting at 85° and yielding a crystallized chlorhydrate or sulphate. Angosturine turns red when touched with concentrated sulphuric acid, or green if nitric acid or iodic acid, or other oxydizing substances, have been previously mixed with the sulphuric acid. The alcoholic solution of the alkaloid is of decidedly alkaline reaction. A cold aqueous infusion of angostura bark yields an abundant red-brown precipitate with ferric chloride. Thin slices of the bark are not coloured by solution of ferrous sulphate, so that tannin appears to be absent.

=Uses=—Angostura bark is a valuable tonic in dyspepsia, dysentery and chronic diarrhœa, but is falling into disuse.

=Adulteration=—About the year 1804, a quantity of a bark which proved to be that of _Strychnos Nux Vomica_ reached Europe from India, and was mistaken for Cusparia. The error occasioned great alarm and some accidents, and the use of angostura was in some countries even prohibited. The means of distinguishing the two barks (which are not likely to be again confounded) are amply contained in the above-given descriptions and tests, and at length pointed out by Oberlin and Schlagdenhauffen. They also described the bark of _Esenbeckia febrifuga_ Martius (_Evodia febrifuga_ Saint Hilaire), a Brazilian tree belonging to the same natural order. Maisch[426] was the first to draw attention to this “_new false Angostura bark_.” It is at once distinguished by being devoid of aromatic properties; its taste is purely bitter.

FOLIA BUCHU.

_Folia Buceo_; _Buchu_, _Bucchu_, _Bucha or Buka Leaves_; F. _Feuilles de Bucco_; G. _Bukublätter_.

=Botanical Origin=—The Buchu leaves are afforded by three species of _Barosma_.[427] The latter are erect shrubs some feet in height, with glabrous rod-like branches, opposite leaves furnished with conspicuous oil-cells on the toothed margin as well as generally on the under surface. The younger twigs and several parts of the flower are also provided with oil-cells. The white flowers with 5-partite calyx, and the fruit formed of five erect carpels, are often found, together with small leafy twigs, in the drug of commerce.

The leaves of the three species referred to may be thus distinguished:—

1. _Barosma crenulata_ Hook. (_B. crenata_ Kunze).—Oblong, oval, or obovate, obtuse, narrowed towards the base into a distinct petiole; margin serrulate or crenulate; dimensions, ¾ to 1½ inches long, ³/₁₀ to ⁴/₁₀ of an inch wide.

2. _B. serratifolia_ Willd.—Linear-lanceolate, equally narrowed towards either end, three-nerved, apex truncate always furnished with an oil-cell; margin sharply serrulate; 1-1½ inches long by about ²/₁₀ of an inch wide.

3. _B. betulina_ Bartling.—Cuneate-obovate, apex recurved; margin sharply denticulate, teeth spreading; ½ to ¾ of an inch long by ³/₁₀ to ⁵/₁₀ wide. Substance of the leaf more harsh and rigid than in the preceding.

_B. crenulata_ and _B. betulina_ grow in the Divisions of Clanwilliam and Worcester, north and north-east of Cape Town, and the former even on Table Mountain close to the capital; _B. serratifolia_ is found in the Division of Swellendam farther south.

=History=—The use of Buchu leaves was learnt from the Hottentots by the colonists of the Cape of Good Hope. The first importations of the drug were consigned to the house of Reece & Co., of London, who introduced it to the medical profession in 1821.[428] The species appears to have been _B. crenulata_.

=Description=—In addition to the characters already pointed out, we may observe that buchu leaves of either of the kinds mentioned are smooth and glabrous, of a dull yellowish-green hue, somewhat paler on the under side, on which oil-cells in considerable number are perceptible.

[426] _Am. Journ. of Pharm._ 1874. 50; also _Yearbook of Pharm._ 1874. 91.

[427] From βαρὺς, _heavy_, and ὀσμὴ, _odour_.

[428] R. Reece, _Monthly Gazette of Health_ for Feb. 1821. 799.

The leaves of _B. crenulata_ vary in shape and size in different parcels, in some the leaves being larger and more elongated than in others, probably according to the luxuriance of the bushes in

## particular localities. Those of _B. serratifolia_ and _B. betulina_

present but little variation. Each kind is always imported by itself. Those of _B. betulina_ are the least esteemed, and fetch a lower price than the others, yet appear to be quite as rich in essential oil.

Buchu leaves have a penetrating peculiar odour and a strongly aromatic taste.

=Microscopic Structure=—The essential oil is contained in large cells close beneath the epidermis of the under side of the leaf. The oil-cells are circular and surrounded by a thin layer of smaller cells; they consequently partake of the character of the oil-ducts in the aromatic roots of _Umbelliferæ_ and _Compositæ_. The latter, however, are elongated.

The upper side of the leaf of _Barosma_ exhibits an extremely interesting peculiarity[429]. There is a colourless layer of cells separating the epidermis from the green inner tissue (mesophyllum). If the leaves are examined under alcohol or almond oil the colourless layer is seen to be very narrow, and the thin walls of its cells shrunken and not clearly distinguishable. If the transverse sections are examined under water, these cells immediately swell up, and become strongly distended, giving off an abundance of mucilage, the latter being afforded by the solution of the very cell-walls. The mucilage of buchu leaves thus originates in the same way as in flax seed or quince seed, but in the former the epidermis is thrown off without alteration. We are not aware that other mucilaginous leaves possess a similar structure, at least not those of _Althæa officinalis_ and of _Sesamum_ which we examined[430].

=Chemical Composition=—The leaves of _B. betulina_ afforded us by distillation 1·56 per cent, of volatile oil[431], which has the odour rather of peppermint than of buchu, and deviates the ray of polarized light considerably to the left. On exposure to cold it furnishes a camphor which, after re-solution in spirit of wine, crystallizes in needle-shaped forms. After repeated purification in this manner, the crystals of _Barosma Camphor_ have an almost pure peppermint odour; they fuse at 85° C., and begin to sublime at 110° C. After fusion they again solidify only at 50° C. Submitted to elementary analysis, the crystals yielded us 74·08 per cent. of carbon and from 9 to 10 per cent. of hydrogen[432]. Barosma camphor is abundantly soluble in bisulphide of carbon.

The crude oil from which the camphor has been separated has a boiling point of about 200° C., quickly rising to 210° or even higher. That which distilled between these temperatures was treated with sodium, rectified in a current of common coal gas and submitted to elementary analysis, afforded us 77·86 per cent, of carbon and 10·58 of hydrogen. The formula C₁₀H₁₆O would require 78·94 of carbon and 10·53 of hydrogen.

Wayne’s experiments[433] appear to indicate that the oil also contains a substance capable of being converted into _salicylic acid_. An aqueous infusion of buchu leaves turns beautifully yellow if it is mixed with alkali.

[429] Flückiger in _Schweiz. Wochenschrift für Pharm._ Dec. 1873, with plate.

[430] See also Radlkofer, _Monographie der Sapindaceen-Gattung Serjania_, München, 1875, p. 100-105.

[431] Messrs. Allen and Hanburys operating on larger quantities obtained 1.63 per cent.—_Barosma serratifolia_ appears to be less rich, according to Bedford (1863).

[432] Our supply of the substance having been exhausted by two analyses we cannot regard the above figures as sufficient for the calculation of a formula.

[433] _Am. Journ. of Pharm._ 1876. 19.

On addition of perchloride of iron the infusion assumes a dingy brownish-green colour changing to red by an alkali. The infusion added to a concentrated solution of acetate of copper causes a yellow precipitate[434] which dissolves in caustic potash, affording a green solution. This may be due to the presence of a substance of the quercitrin or rutin class.

When the leaves are infused in warm water, the mucilage noticed under the microscope may easily be pressed out. It requires for precipitation a large amount of alcohol, being readily miscible with dilute alcohol. Neutral acetate of lead produces a yellow precipitate in an infusion of the leaves; the liquid affords a precipitate by a subsequent addition of _basic_ acetate of lead. The latter precipitate is (probably) due to the mucilage, that afforded by neutral acetate partly to mucilage and

## partly, we suppose, to rutin or an allied substance. Yet the mucilage

of buchu leaves is of the class which is not properly dissolved by water, but only swells up like tragacanth.

The leaves of _B. crenulata_ afforded us upon incineration 4·7 per cent. of ash. Jones (1879) obtained on an average 4·54 per cent. from the same species; 5·27 from _B. serratifolia_; and 4·49 from _B. betulina_. He pointed out the presence of manganate in this ash.

The _Diosmin_ of Landerer[435] is entirely unknown to us.

=Commerce=—The export of buchu from the Cape Colony in 1872 was 379,125 lb., about one-sixth of which quantity was shipped direct to the United States.[436]

=Uses=—Buchu is principally administered in disorders of the urino-genital organs. It is reputed diuretic and diaphoretic. In the Cape Colony the leaves are much employed as a popular stimulant and stomachic, infused in water, sherry, or brandy. They are also extensively used in the United States, both in regular medicine and by the vendors of secret remedies.

=Substitutes=—The leaves of _Empleurum serrulatum_ Ait., a small shrub of the same order as _Barosma_ and growing in the same localities, have been imported rather frequently of late and sold as _Buchu_. They have the same structure as regards mucilage, and nearly the same form as those of _B. serratifolia_, but are easily distinguished. They are still narrower, and often longer than those of _B. serratifolia_, devoid of lateral veins, and terminate in an _acute_ point _without an oil-duct_. They have a bitterish taste and a less powerful odour than those of Barosma, even in fresh leaves as imported in London. The odour of _Empleurum_ is moreover distinctly different from that of the leaves of Barosma. The flowers of _Empleurum_ are still more distinct, for they are apetalous and reddish-brown. The fruit consisting of a single, compressed, oblong carpel, terminated by a flat-shaped horn, is quite unlike that of buchu.

The leaves of _Barosma Eckloniana_ Berg (regarded by Sonder[437] as a form of _B. crenulata_) have to our knowledge been imported on one occasion (1873). They are nearly an inch long, oval, _rounded at the base_, strongly crenate, and grow from _pubescent_ shoots.

[434] It seems _green_ as long as it is in the blue cupric liquid.

[435] Gmelin’s _Chemistry_, xviii 194.

[436] _Blue Book_ published at Cape Town, 1873.

[437] Harvey and Sonder, _Flora Capensis_, i. (1859-60) 393.

We have seen other leaves which had been imported from South Africa and offered as buchu; but though probably derived from allied genera they were not to be mistaken for the genuine drug.

RADIX TODDALIÆ.

=Botanical Origin=—_Toddalia aculeata_ Pers., a ramous prickly bush,[438] often climbing over the highest trees, common in the southern parts of the Indian peninsula as the Coromandel Coast, South Concans, and Canara, also found in Ceylon, Mauritius, the Indian Archipelago and Southern China.

=History=—The pungent aromatic properties which pervade the plant, but especially the fresh root-bark, are well known to the natives of India and have been utilized in their medical practice. They have also attracted the attention of Europeans, and the root of the plant is now recognized in the _Pharmacopœia of India_.

It is from this and other species of _Toddalia_, or from the allied genus _Zanthoxylum_,[439] that a drug is derived which under the name of _Lopez Root_ had once some celebrity in Europe. This drug which was more precisely termed _Radix Indica Lopeziana_ or _Root of Juan Lopez Pigneiro_, was first made known by the Italian physician Redi,[440] who described it in 1671 from specimens obtained by Pigneiro at the mouth of the river Zambesi in Eastern Africa,—the very locality in which in our times _Toddalia lanceolata_ Lam. has been collected by Dr. Kirk.[441] It was actually introduced into European medicine by Gaubius[442] in 1771 as a remedy for diarrhœa, and acquired so much reputation that it was admitted to the Edinburgh Pharmacopœia of 1792. The root appears to have been sometimes imported from Goa, but its place of growth and botanical origin were entirely unknown, and it was always extremely rare and costly.[443] It has long been obsolete in all countries except Holland, where until recently it was to be met with in the shops. The _Pharmacopœia Neerlandica_ of 1851 says of it “_Origo botanica perquam dubia—Patria Malacca?_”

[438] Fig. in Bentley and Trimen,