RUTACEA

CORTEX ANGOSTURA.

Cortex Cusparia; Angostura Bark, Cusparia Bark, Carony Bark; F. Ecorce d'Angusture de Colombie; G. Angostura-Rinde.

Botanical Origin-Galipea Cusparia St. Hilaire (G. officinalis Hancock, Bonplandia trifoliata Willd., Cusparia trifoliata Engler 1874, Flora Brasil. 113), a small tree, 12 to 15 feet high, with a trunk 3 to 5 inches in diameter, growing in abundance on the mountains of San Joaquin de Caroni in Venezuela, between 7° and 8° N. lat., also according to Bonpland1 near Cumana. According to Hancock, who was well acquainted with the tree, it is also found in the Missions of Tumeremo, Uri, Alta Gracia, and Cupapui, districts lying eastward of the Caroni and near its junction with the Orinoko. The bark is brought into commerce by way of Trinidad.

History-Angostura Bark is said to have been used in Madrid by Mutis as early as 17593 (the year before he left Spain for South America,) but it was certainly unknown to the rest of Europe until much later. Its real introducer was Brande, apothecary to Queen Charlotte, and father of the distinguished chemist of the same name, who drew attention to some parcels of the bark imported into England in 1788. In the same year a quantity was sent to a London drug firm by Dr. Ewer of Trinidad, who describes it as brought to that island from Angostura by the Spaniards. The drug continued to arrive in Europe either by way of Spain or England, and its use was gradually diffused. In South America it is known as Quina de Caroni and Cascarilla del Angostura.

Description-The bark occurs in flattish or channelled pieces, or in quills rarely as much as 6 inches in length and mostly shorter. The flatter pieces are an inch or more in width and of an inch in thickness. The outer side of the bark is coated with a yellowish-grey corky layer, often soft enough to be removeable with the nail, and then displaying a dark brown, resinous under surface. The inner side is light brown with a rough, slightly exfoliating surface indicating close adhesion to the wood, strips of which are occasionally found attached to it ; the obliquely cut edge also shows that it is not very easily detached.

The bark has a short, resinous fracture, and displays on its transverse edge sharply defined white points, due to deposits of oxalate of calcium. It has a bitter taste and a nauseous musty odour.

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.'

Chemical Composition-Angostura bark owes its peculiar odour to an essential oil which it was found by Herzog 2 to yield to the extent of per cent. It is probably a mixture of a hydrocarbon (C1oH16) 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.

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 13 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 CHNO". 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 diarrhoea, 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 Îndia, 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 is also figured by Berg, Anatomischer Atlas, Tab. 37.

1 Journ. de Pharm. et de Chimie, 28 (1877), 226; plates I., II., III. The bark

2 Archiv d. Pharm. xcii. (1858) 146.

Brazilian tree belonging to the same natural order. Maisch' 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.2 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, to 14 inches long, o of an inch wide.

to

2. B. serratifolia Willd.-Linear-lanceolate, equally narrowed towards either end, three-nerved, apex truncate always furnished with an oil-cell; margin sharply serrulate; 1-1 inches long by about an inch wide.

of

3. B. betulina Bartling.-Cuneate-obovate, apex recurved; margin sharply denticulate, teeth spreading; to of an inch long by to 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 1821.3 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.

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.

1 Am. Journ. of Pharm. 1874. 50; also Yearbook of Pharm. 1874. 91. 2 From Bapus, heavy, and doμi, odour.

3 R. Reece, Monthly Gazette of Health for Feb. 1821. 799.

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 oilcells 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 Umbelliferce and Composite. The latter, however, are elongated.

The upper side of the leaf of Barosma exhibits an extremely interesting peculiarity. 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 Althaea officinalis and of Sesamum which we examined.2

Chemical Composition-The leaves of B. betulina afforded us by distillation 1:56 per cent. of volatile oil, 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. 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" appear to indicate that the oil also contains

1 Flückiger in Schweiz. Wochenschrift für Pharm. Dec. 1873, with plate.

2 See also Radlkofer, Monographie der Sapindaceen-Gattung Serjania, München, 1875, p. 100-105.

3 Messrs. Allen and Hanburys operating on larger quantities obtained 1'63 per cent.

-Barosma serratifolia appears to be less rich, according to Bedford (1863).

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.

5 Am. Journ. of Pharm. 1876. 19.

a substance capable of being converted into salicylic acid. An aqueous infusion of buchu leaves turns beautifully yellow if it is mixed with

alkali.

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' 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 47 per cent. of ash. Jones (1879) obtained on an average 454 per cent. from the same species; 527 from B. serratifolia; and 4:49 from B. betulina. He pointed out the presence of manganate in this ash.

The Diosmin of Landerer' 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.

Uses-Buchu is principally administered in disorders of the urinogenital 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 oilduct. 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* as

1 It seems green as long as it is in the

blue cupric liquid.

Gmelin's Chemistry, xviii. 194.

3 Blue Book published at Cape Town, 1873. 4 Harvey and Sonder, Flora Capensis, i. (1859-60) 393.