EUPHORBIUM.

Euphorbium, Gum Euphorbium; F. Gomme-résine d’Euphorbe; G. Euphorbium.

Botanical Origin—Euphorbia resinifera Berg, a leafless, glaucous, perennial plant resembling a cactus, and attaining 6 or more feet in height. Its stems are ascending, fleshy and quadrangular, each side measuring about an inch. The angles of the stem are furnished at intervals with pairs of divergent, horizontal, straight spines about ¼ of an inch long, and confluent at the base into ovate, subtriangular discs. These spines represent stipules: above each pair of them is a depression, indicating a leaf-bud. The inflorescence is arranged at the summits of the branches, on stalks each bearing three flowers, the two outer of which are supported on pedicels. The fruit is tricoccous, ³/₁₀ of an inch wide, with each carpel slightly compressed and keeled.[2070]

The plant is a native of Morocco, growing on the lower slopes of the Atlas in the southern province of Suse. Dr. Hooker and his fellow-travellers met with it in 1870 at Netifa and Imsfuia,[2071] south-east of the city of Morocco, which appears to be its westward limit.

History—Euphorbium was known to the ancients. Dioscorides[2072] and Pliny[2073] both describe its collection on Mount Atlas in Africa, and notice its extreme acridity. According to the latter writer, the drug received its name in honour of Euphorbus, physician to Juba II., king of Mauritania. This monarch, who after a long reign died about a.d. 18, was distinguished for his literary attainments, and was the author of several books[2074] which included treatises on opium and euphorbium. The latter work was apparently extant in the time of Pliny.

Euphorbium is mentioned by numerous other early writers on medicine, as Rufus Ephesius, who probably flourished during the reign of Trajan, by Galen in the 2nd century, and by Vindicianus and Oribasius in the 4th. Aëtius and Paulus Ægineta, who lived respectively in the 6th and 7th centuries, were likewise acquainted with it; and it was also known to the Arabian school of medicine. In describing the route from Aghmat to Fez, El-Bekri[2075] of Granada, in 1068, mentioned the numerous plants “El-forbioun” growing in the country of the Beni Ouareth, a tribe of the Sanhadja; the author noticed the spiny herbaceous stems of the shrub abounding in the purgative milky juice.

Höst[2076] (1760-1768) stated that the plant, which he also correctly compared with Opuntia, is growing near Agader, south of Mogador.

The plant yielding euphorbium was further described at the beginning of the present century by an English merchant named Jackson, who had resided many years in Morocco. From the figures he published,[2077] the species was doubtfully identified with Euphorbia canariensis L., a large cactus-like shrub, with quadrangular or hexagonal stems, abounding on scorched and arid rocks in the Canary Islands.

In the year 1849 it was pointed out in the (Admiralty) Manual of Scientific Enquiry, that the stems of which fragrants are found in commercial euphorbium, do not agree with those of E. canariensis. Berg carried the comparison further, and finally from the fragments in question drew up a botanical description, which with an excellent figure he published[2078] as Euphorbia resinifera. The correctness of his observations has been fully justified by specimens[2079] which were transmitted to the Royal Gardens, Kew, in 1870, and now form flourishing plants.

The drug has a place in all the early printed pharmacopœias.

Collection—Euphorbium is obtained by making incisions in the green fleshy branches of the plant. These incisions occasion an abundant exudation of milky juice which hardens by exposure to the air, encrusting the stems down which it flows; it is finally collected in the latter part of the summer. So great is the acridity of the exudation, that the collector is obliged to tie a cloth over his mouth and nostrils, to prevent the entrance of the irritating dust. The drug is said to be collected in districts lying east and south-east of the city of Morocco.

Description—The drug consists of irregular pieces, seldom more than an inch across and mostly smaller, of a dull yellow or brown waxy-looking substance, among which portions of the angular spiny stem of the plant may be met with. Many of the pieces encrust a tuft of spines or a flower-stalk or are hollow. The substance is brittle and translucent; splinters examined under the microscope exhibit no particular structure, even by the aid of polarized light; nor are starch granules visible.[2080] The odour is slightly aromatic, especially if heat is applied; but 10 lb. of the drug which we subjected to distillation afforded no essential oil. Euphorbium has a persistent and extremely acrid taste; its dust excites violent sneezing, and if inhaled, as when the drug is powdered, occasions alarming symptoms.

Chemical Composition—Analysis of euphorbium performed by one of us[2081] showed the composition of the drug to be as follows:—

The amorphous resin is readily soluble in cold spirit of wine containing about 70 per cent. of alcohol. The solution has no acid reaction, but an extremely burning acrid taste: in fact it is to the amorphous indifferent resin that euphorbium owes its intense acridity. By evaporating the resin with alcoholic potash and neutralizing the residue with a dilute aqueous acid, a brown amorphous substance, the Euphorbic Acid of Buchheim,[2082] is precipitated. It is devoid of the acridity of the resin from which it originated, but has a bitterish taste.

From the drug deprived of the amorphous resin as above stated, ether (ether or petroleum) takes up the Euphorbon, which may be obtained in colourless, although not very distinct crystals, which are at first not free from acrid taste. But by repeated crystallizations and finally boiling in a weak solution of permanganate of potassium, they may be so far purified as to be entirely tasteless. Euphorbon is insoluble in water; it requires about 60 parts of alcohol, sp. gr. 0·830, for solution at the ordinary temperature. In boiling alcohol euphorbon dissolves abundantly, also in ether, benzol, amylic alcohol, chloroform, acetone, or glacial acetic acid.

Euphorbon melts at 116° C. (113° to 114°, Hesse) without emitting any odour. By dry distillation a brownish oily liquid is obtained, which claims further examination. If euphorbon dissolved in alcohol is allowed to form a thin film in a porcelain capsule, and is then moistened with a little concentrated sulphuric acid, a fine violet hue is produced in contact with strong nitric acid slowly added by means of a glass rod. The same reaction is displayed by Lactucerin (see Lactucarium), to which in its general characters euphorbon is closely allied.

Hesse (1878) assigns to euphorbon the formula C₁₅H₂₄O, and points out that its solutions in chloroform or ether are dextrogyrate.

As to the mucilage of euphorbium, it may be obtained from that portion of the drug which has been exhausted by cold alcohol and by ether. Neutral acetate of lead, as well as silicate or borate of sodium, precipitate this mucilage, which therefore does not agree with gum arabic.

If an aqueous extract of euphorbium is mixed with spirit of wine, and the liquid evaporated, the residual matter assumes a somewhat crystalline appearance, and exhibits the reactions of Malic Acid. Subjected to dry distillation, white scales and acicular crystals of Maleic and Fumaric Acids, produced by the decomposition of the malic acid, are sublimed into the neck of the retort. A sublimate of the same kind may sometimes be obtained directly by heating fragments of euphorbium. Among the mineral constituents of the drug, chloride of sodium and calcium are noticeable; scarcely any salt of potassium is present.

Commerce—The drug is shipped from Mogador. The quantity imported into the United Kingdom in 1870 is given in the Annual Statement of Trade as 12 cwt.

Uses—Euphorbium was formerly employed as an emetic and purgative, but as an internal remedy it is completely obsolete. We have been told that it is now in some demand as an ingredient of a paint for the preservation of ships’ bottoms.

CORTEX CASCARILLÆ.

Botanical Origin—Croton Eluteria Bennett,[2084] a shrub or small tree, exclusively native of the Bahama Islands.

History—It is not improbable that cascarilla bark was imported into Europe in the first half of the 17th century, as there was much intercourse subsequent to the year 1630 between England and the Bahamas.[2085] These islands were occupied in 1641 by the Spaniards, who became at that time acquainted with the Peruvian bark or Cascarilla (see page 346), as we have shown at page 343. The external appearance of the bark of Eluteria being somewhat similar to that of Cinchona quills, the former began soon to be known under the name of China nova. This drug occurs along with true Cinchona bark, China de China, in the tariff of the year 1691 of the pharmaceutical shops of the German town Minden, in Westphalia. There can be no doubt that the cheaper kind of “China,” called China nova, was really the bark under examination, for in many other tariffs a few years later distinct mention is made of Cortex Chinæ novæ seu Schacorillæ; and Savary, in his “Dictionnaire de Commerce” (1723, 1750), confirms the fact, adding that it was first seen in the great fair of Brunswick.[2086] Another early statement concerning Cascarilla bark likewise refers to the duchy of Brunswick. Stisser, a professor of anatomy, chemistry, and medicine in the University of Helmstedt in Brunswick, relates that he received the drug under the name of Cortex Eleuterii from a person who had returned from England, in which country, he was assured, it was customary to mix it with tobacco for the sake of correcting the smell of the latter when smoked. He also mentions that it had been confounded with Peruvian bark, from which however it was very distinct in odour, etc.[2087] Eleutheria bark was then frequently prescribed as a febrifuge in the place of Cinchona bark, then a more expensive medicine. Hence the name cascarilla, signifying in Spanish little bark, which was the customary designation of Peruvian bark, was erroneously applied to the Bahama bark, until at last it quite superseded the original and more correct appellation. That of China nova was subsequently applied to a quite different bark (see page 364). The drug under notice was first introduced into the London Pharmacopœia in 1746 as Eleutheriæ Cortex, which was its common name among druggists down to the end of the last century. In the Bahamas the name cascarilla is still hardly known, the bark being there called either Sweet Wood Bark or Eleuthera Bark.

The plant affording cascarilla has been the subject of much discussion, arising chiefly from the circumstance that several nearly allied West Indian species of Croton yield aromatic barks resembling more or less the officinal drug. Catesby in 1754 figured a Bahama plant, Croton Cascarilla Bennett, from which the original Eleuthera Bark was probably derived, though it certainly affords none of the cascarilla of modern commerce. Woodville in 1794, and Lindley in 1838, both investigated the botany of the subject, the latter having the advantage of authentic specimens communicated by the Hon. J. C. Lees of New Providence, to whom one of us also is indebted for a similar favour. The question was not however finally set at rest until 1859, when J. J. Bennett by the aid of specimens collected in the Bahamas by Daniell in 1857-8, drew up lucid diagnoses of the several plants which had been confounded, and disentangled their intricate synonymy.[2088]

Description—Cascarilla occurs in the form of tubular or channelled pieces of a dull brown colour, somewhat rough and irregular, rarely exceeding 4 inches in length by ½ an inch in diameter. The chief bulk of that at present imported is in very small thin quills and fragments, often scarcely an inch in length, and evidently stripped from very young wood. The younger bark has a thin suberous coat easily detached, blotched or entirely covered with the silvery white growth of a minute lichen (Verrucaria albissima Ach.), the perithecium of which appears as small black dots. The older bark is more rugose, irregularly tessellated by longitudinal cracks and less numerous transverse fissures. Beneath the corky envelope the bark is greyish-brown.

The bark breaks readily with a short fracture, the broken surface displaying a resinous appearance. It has a very fragrant odour, especially agreeable when several pounds of it are reduced to coarse powder and placed in a jar; it has a nauseous bitter taste. When burned it emits an aromatic smell, and hence is a common ingredient in fumigating pastilles.

Microscopic Characters—The suberous coat is made up of numerous rows of tabular cells, the outermost having their exterior walls much thickened. The mesophlœum exhibits the usual tissue, containing starch, chlorophyll, essential oil, crystals of oxalate of calcium, and a brown colouring matter. The latter assumes a dark bluish coloration on addition of a persalt of iron. In the inner portion of that layer ramified laticiferous vessels are also present. The liber consists of parenchyme and of fibrous bundles, intersected by small medullary rays. On the transverse section, the fibrous bundles show a wedge-shaped outline; they are for the most part built up, not of true liber-fibres, but of cylindrical cells having their transverse walls perforated sieve-like (vasa cribriformia). The contents of the parenchymatous part of the liber are the same as in the mesophlœum; as to the oxalate of calcium, the variety of its crystals is remarkable.[2089]

Chemical Composition—Cascarilla contains a volatile oil, which it yields to the extent of 1·1 per cent. According to Völckel (1840), it is a mixture of at least two oils, the more volatile of which is probably free from oxygen. Gladstone (1872) assigns to the hydrocarbon of cascarilla oil the composition of oil of turpentine. By examining the oil optically we found it to have a weak rotatory power—some samples deviated to the right, some to the left. The resin, in which cascarilla is rich, has not yet been examined more exactly.

The bitter principle was isolated in 1845 by Duval, and called Cascarillin. C. and E. Mylius (1873) have obtained it from a deposit in the officinal extract, in microscopic prisms readily soluble in ether or hot alcohol, very sparingly in water, chloroform or spirit of wine. It melts at 205° C., is not volatile, nor a glucoside. Its composition answers to the formula C₁₂H₁₈O₄.

Commerce—The bark is shipped from Nassau, the chief town of New Providence (Bahamas), and is usually packed in sacks. The quantity imported into the United Kingdom in 1870 was 12,261 cwt., valued at £16,482. The exports from the Bahamas were 676 cwt. in 1875, and 1,093 cwt. in 1876.

Uses—Cascarilla is prescribed as a tonic, usually in the form of a tincture or infusion.

Adulteration—A spurious cascarilla bark has lately been noticed in the London market; it was imported from the Bahamas mixed with the genuine, to which it bears a close similarity. The quills of it resemble the larger quills of cascarilla; though covered with a lichen, the latter has not the silvery whiteness of the Verrucaria of cascarilla. The spurious bark has a suberous coat that does not split off; its inner surface is pinkish-brown, and distinctly striated longitudinally. In microscopic structure the bark may be said to resemble cascarilla and still more copalchi. But it is at once distinguishable by its numerous roundish groups of sclerenchymatous cells, which become very evident when thin sections are moistened with ammonia, and then with solution of iodine in iodide of potassium. The bark has an astringent taste, without bitterness or aroma; its tincture is not rendered milky by addition of water, but is darkened by ferric chloride,—in these respects differing from a tincture of cascarilla. Mr. Holmes[2090] suggests that this spurious cascarilla is probably the bark of Croton lucidus L.

Copalchi Bark; Quina blanca of the Mexicans.

This drug is derived from Croton niveus[2091] Jacquin (C. Pseudo-China Schlechtendal), a shrub growing 10 feet high, native of the West Indian Islands, Mexico, Central America, New Granada and Venezuela. It has occasionally been imported into Europe, in quills a foot or two in length, much stouter and thicker than those of cascarilla, to which in odour and taste it nearly approximates. The bark has a thin, greyish, papery suberous layer, which when removed shows the surface marked with minute transverse pits, like the lines made by a file; it has a short fracture.[2092]

Copalchi bark was examined by J. Eliot Howard,[2093] and found to contain a minute proportion of a bitter alkaloid soluble in ether, which resembled quinine in yielding a deep green colour when treated with chlorine and ammonia, though it did not afford any characteristic compound with iodine. Mauch,[2094] who also analysed the bark, could not obtain from it any organic base. He extracted by distillation the essential oil, which he found to consist of a hydrocarbon and an organic acid,—the latter not examined; he likewise got from the bark an uncrystallizable bitter principle, which proved to be not a glucoside.

SEMEN TIGLII.

Botanical Origin—Croton Tiglium[2095] L. (Tiglium officinale Klotzsch), a small tree, 15 to 20 feet high, indigenous to the Malabar Coast and Tavoy, cultivated in gardens in many parts of the East, from Mauritius to the India Archipelago. The tree has small inconspicuous flowers, and brown, capsular, three-celled fruits, each cell containing one seed. The leaves have a disagreeable smell and nauseous taste.

History—In Europe, the seeds and wood of the tree were first described in 1578 by Christoval Acosta—the former, with a figure of the plant, appearing under the name of Piñones de Maluco.[2096] The plant was also described and figured by Rheede (1679)[2097] and Rumphius (1743).[2098] The seeds, which were officinal in the 17th century, but had become obsolete, were recommended about 1812 by English medical officers in India,[2099] and the expressed oil by Perry, Frost, Conwell and others about 1821-24. The oil then in use was imported from India, and was often of doubtful purity, so that some druggists felt it necessary to press the seeds for themselves.[2100]

Description—Croton seeds are about half an inch long, by nearly ⅖ of an inch broad, ovoid or bluntly oblong, divided longitudinally into two unequal parts, of which the more arched constitutes the dorsal and the flatter the ventral side. From the hilum, a fine raised line (raphe) passes to the other end of the seed, terminating in a darker point, indicating the chalaza. The surface of the seed is more or less covered with a bright cinnamon-brown coat, which when scraped shows the thin, brittle, black testa filled with a whitish, oily kernel, invested with a delicate seed-coat. The kernel is easily split into two halves consisting of oily albumen, between which lie the large, veined, leafy cotyledons and the radicle. The taste of the seed is at first merely oleaginous, but soon becomes unpleasantly and persistently acrid.

Microscopic Structure—The testa consists of an outer layer of radially arranged, much elongated and thick-walled cells; the inner parenchymatous layer contains small vascular bundles. The soft tissue of the albumen is loaded with drops of fatty oil. If this is removed by means of ether and weak potash lye, there remain small granules of albuminoid matter, the so-called Aleuron, and crystals of oxalate of calcium.

Chemical Composition—The principal constituent of croton seeds is the fatty oil, the Oleum Crotonis or Oleum Tiglii of pharmacy of which the kernels afford from 50 to 60 per cent. That used in England is for the most part expressed in London, and justly regarded as more reliable than that imported from India, with which the market was formerly supplied. It is a transparent, sherry-coloured, viscid liquid, slightly fluorescent, and having a slight rancid smell and an oily, acrid taste. Its solubility in alcohol (·794) appears to depend in great measure on the age of the oil, and the greater or less freshness of the seeds from which it was expressed,—oxidized or resinified oil dissolving the most readily.[2101] We found the oil which one of us had extracted by means of bisulphide of carbon to be levogyre.

Croton oil consists chiefly of the glycerinic ethers of the common fatty acids, such as stearic, palmitic, myristic and lauric acids. They partly separate in the cold; the acids also may partly be obtained by passing nitrous acid through croton oil. There are also present in the latter, in the form of glycerinic ethers, the more volatile acids, as formic, acetic, isobutyric and one of the valerianic acids.[2102] The volatile part of the acids yielded by croton oil contains moreover an acid which was regarded by Schlippe (1858) as angelic acid, C₅H₈O₂. Yet in 1869 it was shown by Geuther and Frölich to be a peculiar acid, which they called Tiglinic acid. Its composition answers to the same formula, C₄H₇COOH, as that of angelic acid; but the melting points (angelic acid 45°, tiglinic 64° C.) and boiling points (angelic acid 185°, tiglinic 198°·5) are different. Both these acids have been mentioned in our article on Flores Anthemidis, at page 386. Tiglinic acid may also be obtained artificially; it is the methylcrotonic acid of Frankland and Duppa (1865).

Schlippe also stated croton oil to afford a peculiar liquid acid termed Crotonic Acid, C₄H₆O₂. According to Geuther and Frölich, however, an acid of this formula does not occur at all in croton oil. By synthetic methods three different acids of that composition are obtainable.

The drastic principle of croton oil has not yet been isolated. Buchheim[2103] suggested that the action of the oil depends upon “Crotonoleic acid,” which however he failed in isolating satisfactorily. It is remarkable that the wood and leaves of Croton Tiglium appear to partake also of the drastic properties of the seeds.

Schlippe asserts that he has separated the vesicating matter of croton oil: if the oil be agitated with alcoholic soda, and afterwards with water, the supernatant liquor will be found free from acridity, while the alcoholic solution will yield, on addition of hydrochloric acid, a small quantity of a dark brown oil, called Crotonol, possessing vesicating properties. We have not succeeded in obtaining it, nor, so far as we know, has any other chemist except its discoverer.

The shells of the seeds (testa) yield upon incineration 2·6 per cent. of ash; the kernels dried at 100° C. 3·0 per cent.

Commerce—The shipments of croton seeds arrive chiefly from Cochin or Bombay, packed in cases, bales or robbins; but there are no statistics to show the extent of the trade.

Uses—Croton seeds are not administered. The oil is given internally as a powerful cathartic, and is applied externally as a rubefacient.

Substitutes—The seeds of Croton Pavanæ Hamilton, a native of Ava and Camrup (Assam), and those of C. oblongifolius Roxb., a small tree common about Calcutta, are said to resemble those of C. Tiglium L., but we have not compared them. Those of Baliospermum montanum Müll. Arg. (Croton polyandrus Roxb.) partake of the nature of croton seeds, and according to Roxburgh are used by the natives of India as a purgative.

SEMEN RICINI.

Botanical Origin—Ricinus communis L., the castor oil plant, is a native of India where it bears several ancient Sanskrit names.[2104] By cultivation, it has been distributed through all the tropical and many of the temperate countries of the globe. In the regions most favourable to its growth, it attains a height of 40 feet. In the Azores, and the warmer Mediterranean countries as Algeria, Egypt, Greece, and the Riviera, it becomes a small tree, 10 to 15 feet high; while in France, Germany, and the south of England, it is an annual herb of noble foliage, growing to a height of 4 or 5 feet. In good summers, it ripens seeds in England and even as far north as Christiania in Norway.

Ricinus communis exhibits a large number of varieties, several of which have been described and figured as distinct species. Müller, after a careful examination of the whole series, maintains them as a single species, of which he allows 16 forms, more or less well marked.[2105]

History—The castor oil plant was known to Herodotus who calls it Κίκι, and states that it furnishes an oil much used by the Egyptians, in whose ancient tombs seeds of Ricinus are, in fact, met with.[2106] At the period when Herodotus wrote, it would appear to have been already introduced into Greece, where it is cultivated to the present day under the same ancient name.[2107] The Kikajon of the Book of Jonah, rendered by the translators of the English Bible gourd, is believed to be the same plant. Κίκι is also mentioned by Strabo as a production of Egypt, the oil from which is used for burning in lamps and for unguents.

Theophrastus and Nicander give the castor oil plant the name of Κρότων. Dioscorides, who calls it Κίκι or Κρότων, describes it as of the stature of a small fig-tree, with leaves like a plane, and seeds in a prickly pericarp, observing that the name Κρότων is applied to the seed on account of its resemblance to an insect [Ixodes Ricinus Latr.], known by that appellation. He also gives an account of the process for extracting castor oil (Κίκινον ἔλαιον), which he says is not fit for food, but is used externally in medicine; he represents the seeds as extremely purgative. There is a tolerably correct figure of Ricinus in the famous MS. Dioscorides which was executed for the Empress Juliana Anicia in a.d. 505, and is now preserved in the Imperial Library at Vienna.

The castor oil plant was cultivated by Albertus Magnus, Bishop of Ratisbon, in the middle of the 13th century.[2108] It was well known as a garden plant in the time of Turner (1568), who mentions the oil as Oleum cicinum vel ricininum.[2109] Gerarde, at the end of the same century, was familiar with it under the name of Ricinus or Kik. The oil he says is called Oleum cicinum or Oleum de Cherua,[2110] and used externally in skin diseases.

After this period the oil seems to have fallen into complete neglect, and is not even noticed in the comprehensive and accurate Pharmacologia of Dale (1693). In the time of Hill (1751) and Lewis (1761) Palma Christi seeds were rarely found in the shops, and the oil from them was scarcely known.[2111]

In 1764 Peter Canvane, a physician who had practised many years in the West Indies, published a “Dissertation on the Oleum Palmæ Christi, sive Oleum Ricini; or (as it is commonly call’d) Castor Oil,”[2112] strongly recommending its use as a gentle purgative. This essay, which passed through two editions, and was translated into French, was followed by several others,[2113] thus thoroughly drawing attention to the value of the oil. Accordingly we find that the seeds of Ricinus were admitted to the London Pharmacopœia of 1788, and directions given for preparing oil from them. Woodville in his Medical Botany (1790) speaks of the oil as having “lately come into frequent use.”

At this period and for several years subsequently, the small supplies of the seeds and oil required for European medicine were obtained from Jamaica.[2114] This oil was gradually displaced in the market by that produced in the East Indies: the rapidity with which the consumption increased may be inferred from the following figures, representing the value of the Castor Oil shipped to Great Britain from Bengal in three several years, namely 1813-14, £610; 1815-16, £1269; 1819-20, £7102.[2115]

Description—The fruit of Ricinus is a tricoccous capsule, usually provided with weak prickles, containing one seed in each of its three cells. The seeds attain a length of ³/₁₀ to ⁶/₁₀, and a maximum breadth of ⁴/₁₀ of an inch, and are of a compressed ellipsoid form. The apex of the seed is prolonged into a short beak, on the inner side of which is a large tumid caruncle: from this latter proceeds the raphe as far as the lower end of the ventral surface, where it forks, its point of disappearance through the testa being marked by a minute protuberance. If the caruncle is broken off, a black scar, formed of two little depressions, remains.

The shining grey epidermis is beautifully marked with brownish bands and spots, and in this respect exhibits a great variety of colours and markings. It cannot be rubbed off, but may after maceration be peeled off in leathery strips. The black testa, grey within, is not thicker than in croton seed, but is much more brittle. The kernel or nucleus fills the testa completely, and is easily separated, still covered by the soft white inner membrane.

The kernel in respect to structure and situation of the embryo, agrees exactly with that of Croton Tiglium (p. 565), excepting that the somewhat gaping cotyledons of Ricinus are proportionately broader, and have their thick midrib provided with 2 or 3 pairs of lateral veins. If not rancid, the kernel has a bland taste, with but very slight acridity.

Microscopic Structure—The thin epidermis consists of pentagonal or hexagonal porous tabular cells, the walls of which are penetrated in certain spots by brownish colouring matter, whence the singular markings on the seed. It is these cells only that become blackened when a thin tangential slice is saturated with a solution of ferric chloride in alcohol.

Beneath these tabular cells there is found in the unripe seed[2116] a row of encrusted colourless cells, deposited in a radial direction on the testa. In the mature seed this layer of cells is not perceptible, and therefore appears to perish as the seed ripens. The testa itself is built up of cylindrical, densely packed cells, 300 to 320 mkm. long, and 6 to 10 mkm. in diameter. The kernel shares the structure of that of C. Tiglium, but is devoid of crystals of oxalate of calcium. If the endopleura of Ricinus is moistened with dilute sulphuric acid, acicular crystals of sulphate of calcium separate from it after a few hours.

When thin slices of the kernel are examined under concentrated glycerin, no drops of oil are visible, notwithstanding the abundance of this latter; and it becomes conspicuous only by addition of much water. Hence it is probable that the oil exists in the seed as a kind of compound with its albuminoid contents.[2117] As to the latter, they partly form in the albumen of Ricinus beautiful octohedra or tetrahedra, which are also found in many other seeds.[2118]

Chemical Composition—The most important constituent of the seed is the fixed oil, called Castor Oil, of which the peeled kernels afford at most half of their weight.

The oil, if most carefully prepared from peeled and winnowed seeds by pressure without heat, has but a slightly acrid taste, and contains only a very small proportion of the still unknown drastic constituent of the seeds. Hence the seeds themselves, or an emulsion prepared with them, act much more strongly than a corresponding quantity of oil. Castor oil, extracted by absolute alcohol or by bisulphide of carbon, likewise purges much more vehemently than the pressed oil.

The castor oil of commerce has a sp. gr. of about 0·96, usually a pale yellow tint, a viscid consistence, and a very slight yet rather mawkish odour and taste. Exposed to cold, it does not in general entirely solidify until the temperature reaches -18° C. In thin layers it dries up to varnish-like film.

Castor oil is distinguished by its power of mixing in all proportions with glacial acetic acid or absolute alcohol. It is even soluble in four parts of spirit of wine (·838) at 15° C., and mixes without turbidity with an equal weight of the same solvent at 25° C. The commercial varieties of the oil however differ considerably in these as well as in some other respects.

The optical properties of the oil demand further investigation, as we have found that some samples deviate the ray of polarized light to the right and others to the left.

By saponification castor oil yields several fatty acids, one of which appears to be Palmitic Acid. The prevailing acid (peculiar to the oil) is Ricinoleic Acid, C₁₈H₃₄O₃; it is solid below 0° C., does not solidify in contact with the air by absorption of oxygen, and is not homologous with oleic or linoleic acid, neither of which is found in castor oil. Castor oil is nevertheless thickened if 6 parts of it are warmed with 1 part of starch and 5 of nitric acid (sp. gr. 1·25), Ricinelaïdin being thus formed. From this Ricinelaïdic Acid may easily be obtained in brilliant crystals.

As to the albuminoid matter of the seed, Fleury (1865) obtained 3·23 per cent. of nitrogen which would answer to about 20 per cent. of such substances. The same chemist further extracted 46·6 per cent. of fixed oil, 2·2 of sugar and mucilage, besides 18 per cent. of cellulose.

Tuson in 1864, by exhausting castor oil seeds with boiling water, obtained from them an alkaloid which he named Ricinine. He states that it crystallizes in rectangular prisms and tables, which when heated fuse, and upon cooling solidify as a crystalline mass; the crystals may even be sublimed. Ricinine dissolves readily in water or alcohol, less freely in ether or benzol. With mercuric chloride, it combines to form tufts of silky crystals, soluble in water or alcohol. Werner (1869) on repeating Tuson’s process on 30 lb. of Italian castor oil seeds, also obtained a crop of crystals, which in appearance and solubility had many of the characters ascribed to ricinine, but differed in the essential point that when incinerated they left a residuum of magnesia. Werner regarded them as the magnesium salt of a new acid. Tuson[2119] repudiates the suspicion that ricinine may be identical with Werner’s magnesium compound. E. S. Wayne of Cincinnati (1874) found in the leaves of Ricinus a substance apparently identical with Tuson’s ricinine; but he considers that it has no claim to be called an alkaloid.

The testa of castor oil seeds afforded us 10·7 per cent. of ash, one tenth of which we found to consist of silica. The ash of the kernel previously dried at 100 C. amounts to only 3·5 per cent.

Production and Commerce—Castor oil is most extensively produced in India, where two varieties of the seeds, the large and the small, are distinguished, the latter being considered to yield the better product. In manufacturing the oil, the seeds are gentry crushed between rollers, and freed by hand from husks and unsound grains. At Calcutta, 100 parts of seed yield on an average 70 parts of cleaned kernels, which by the hydraulic press afford 46 to 51 per cent. of their weight of oil; the oil is afterwards subjected to a very imperfect process of purification by heating it with water.[2120]

The exports of castor oil from Calcutta[2121] in the year 1870-71 amounted to 654,917 gallons, of which 214,959 gallons were shipped to the United Kingdom. The total imports of castor oil into the United Kingdom[2122] in the year 1870 were returned as 36,986 cwt. (about 416,000 gallons), valued at £82,490. Of this quantity, British India (chiefly Bengal) furnished about two-thirds; and Italy 11,856 cwt. (about 133,000 gallons), while a small remainder is entered as from “other parts.” In 1876 the imports were 79,677 cwt., valued at £133,838.

Italian Castor Oil, which has of late risen into some celebrity, is pressed from the seed of plants grown chiefly about Verona and Legnago, in the north of Italy. The manufactory of Mr. Bellino Valeri at the latter town produced in the year 1873, 1200 quintals of castor oil, entirely from Italian seed. Two varieties of Ricinus are cultivated in these localities, the black-seeded Egyptian and the red-seeded American; the latter yields the larger percentage, but the oil is not so pale in colour. The seeds are very carefully deprived of their integuments, and having been crushed, are submitted to pressure in powerful hydraulic presses, placed in a room which in winter is heated to about 21° C. The outflow of oil is further promoted by plates of iron warmed to 32-38° C. being placed between the press-bags. The peeled seeds yield about 40 per cent. of oil.[2123]

All the castor oil pressed in Italy is not pressed from Italian seed. By an official return[2124] it appears that in the year 1872-73 there were exported from Bombay to Genoa 1350 cwt. of castor oil seeds, besides 2452 gallons of castor oil. There are no data to show what was exported from the other presidencies of India in that year.

Uses—Castor oil is much valued as a mild and safe purgative; while the commoner qualities are used in soap-making, and in India for burning in lamps. The seeds are not now administered. The leaves of the plant applied in decoction to the breasts of women are said to promote or even to occasion the secretion of milk. This property, which has long been known to the inhabitants of the Cape Verd Islands,[2125] was particularly observed by Dr. M’William about the year 1850. It has even been found that the galactagogue powers of the plant are exerted when the leaves are administered internally.

KAMALA.

Kamela, Glandulæ Rottleræ.

Botanical Origin—Mallotus philippinensis[2126] Müller Arg. (Croton philippensis Lam., Rottlera tinctoria Roxb., Echinus philippinensis Baillon), a large shrub, or small tree, attaining 20 or 45 feet in height, of very wide distribution. It grows in Abyssinia and Southern Arabia, throughout the Indian peninsulas, ascending the mountains to 5000 feet above the sea-level, in Ceylon, the Malay Archipelago, the Philippines, the Loochoo islands, Formosa, Eastern China and in North Australia, Queensland and New South Wales.

The tricoccous fruits of many of the Euphorbiaceæ are clothed with prickles, stellate hairs, or easily removed glands. This is especially the case in the several species of Mallotus, most of which have the capsules covered with stellate hairs, together with small glands. In that under notice, the capsule is closely beset with ruby-like glands which, when removed by brushing and rubbing, constitute the powder known by the Bengali name of Kamala. These glands are not confined to the capsule, but are scattered over other parts of the plant, especially among the dense tomentum with which the under side of the leaf is covered.

History—In India the glands of Mallotus have been long known, for they have several ancient Sanskrit names: one of these is Kapila, which as well as the Telugu Kapila-podi, is sometimes used by Europeans, though not so frequently as the word Kamala or Kamela, which belongs to the Hindustani, Bengali and Guzratti languages. The Sanskrit word Kapila signifies tawny or dusky red, the Tamil Podi means the pollen of a flower or dust in general.

It does not appear that as a drug the glandular powder of Mallotus, or as it is more conveniently called, Kamala, attracted any particular notice in Europe until a very recent period, though it is named by Ainslie, Roxburgh, Royle and Buchanan, the last of whom gives an interesting account of its collection and uses.[2127] In 1852, specimens of it as found in the bazaar of Aden, under the old Arabic name of Wars, were sent to one of us by Port-Surgeon Vaughan, with information as to its properties as a dye for a silk and as a remedy in cutaneous diseases.[2128] But the real introduction of the drug as a useful medicine is due to Mackinnon, surgeon in the Bengal Medical Establishment, who administered it successively in numerous cases of tapeworm. Anderson of Calcutta, C. A. Gordon, and Corbyn in India, and Leared in London, confirmed the observations of Mackinnon, and fully established the fact that kamala is an efficient taenifuge.[2129] It was introduced into the British Pharmacopœia in 1864.

An analogous drug is mentioned by Paulus Ægineta[2130] in the 7th century as well as by the Arabian physicians[2131] as early as the 10th century, under the name of Kanbil or Wars. Ibn Khurdádbah, an Arab geographer, living a.d. 869-885, states that from Yemen come striped silks, ambergris, wars, and gum.[2132] It is described to be a reddish yellow powder like sand, which falls on the ground in the valleys of Yemen, and is a good remedy for tapeworm and cutaneous diseases. One writer compares it to powdered saffron; another speaks of two kinds,—an Abyssinian which is black (or violet), and an Indian which is red. Masudi,[2133] in the first half of the 10th century speaks of qinbil, which he says consists of sandy fruits of red hue. They are useful as an anthelminthic and for cutaneous diseases. A similar explanation of the qinbil is found in Qamus, a dictionary writer in the 13th century in Yemen. About the year 1216, a learned traveller, Abul Abbas Ahmad Annabati,[2134] (Annabati = the botanist) or Abul Abbas el-Nebáti, who was a native of Seville, remarks that the drug is known in the Hejaz and brought from Yemen, but that it is unknown in Andalusia and does not grow there.

Kazwini,[2135] nearly at the same period, was also acquainted with wars, a plant sown in Yemen and resembling Sesam; Constantinus Africanus likewise mentioned “huars.” Wars, Wors, Wurrus or Warras in Arabia properly signifies saffron.

In modern times, we find Niebuhr[2136] speaks of the same substance (as “wars”), stating it to be a dye-stuff, of which quantities are conveyed from Mokha to Oman.

Production—Kamala is one of the minor products of the Government forests in the Madras Presidency, but is also collected in many other parts of India. The following particulars have been communicated to us by a correspondent[2137] in the North-west Provinces:—

“ ... Enormous quantities of Rottlera tinctoria are found growing at the foot of these hills, and every season numbers of people, chiefly women and children, are engaged in collecting the powder for exportation to the plains. They gather the berries in large quantities and throw them into a great basket in which they roll them about, rubbing them with their hands so as to divest them of the powder, which falls through the basket as through a sieve, and is received below on a cloth spread for the purpose. This powder forms the Kamala of commerce, and is in great repute as an anthelminthic, but is most extensively used as a dye. The adulterations are chiefly the powdered leaves, and the fruit-stalks with a little earthy matter, but the percentage is not large. The operations of picking the fruit and rubbing off the powder commence here in the beginning of March and last about a month....”

A similar powder is collected in Southern Arabia, whence it is shipped to the Persian Gulf and Bombay. It is also brought, under the name of Wars, from Hurrur, a town in Eastern Africa, which is a great trading station between the Galla countries and Berbera.[2138] Yet the Arabian and African drug consists in most cases not of kamala, but of those dark glands which we describe further on, at p. 575.

Description—Kamala is a fine, granular, mobile powder, consisting of transparent, crimson granules, the bright colour of which is mostly somewhat deadened by the admixture of grey stellate hairs, minute fragments of leaves and similar foreign matter. It is nearly destitute of taste and smell, but an alcoholic solution poured into water emits a melon-like odour. Kamala is scarcely acted on by water, even at a boiling heat; on the other hand, alcohol, ether, chloroform or benzol extract from it a splendid red resin. Neither sulphuric nor nitric acid acts upon it in the cold, nor does oil of turpentine become coloured by it unless warmed. It floats on water, but sinks in oil of turpentine. When sprinkled over a flame, it ignites after the manner of lycopodium. Heated alone, it emits a slight aromatic odour; if pure, it leaves after incineration about 1·37 per cent. of a grey ash.

Microscopic Structure—The granules of kamala are irregular spherical glands, 50 to 60 mkm. in diameter; they have a wavy surface, are somewhat flattened or depressed on one side, and enclose within their delicate yellowish membrane a structureless yellow mass in which are imbedded numerous, simple, club-shaped cells containing a homogeneous, transparent, red substance. These cells are grouped in a radiate manner around the centre of the flattened side, so that on the side next the observer, 10 to 30 of them may easily be counted, while the entire gland may contain 40 to 60. In a few cases, a very short stalk-cell is also seen at the centre of the base.

When the glands are exhausted by alcohol and potash, and broken by pressure between flat pieces of glass, they separate into individual cells which swell up slightly, while the membranous envelope is completely detached, and appears as a simple coherent film. After this treatment the cells, but not their membranous envelope, acquire by prolonged contact with strong sulphuric acid and iodine water a more or less brown or blue colour: the walls of the cells alone correspond therefore to cellulose. Vogl (1864) supposes that a cell of the epidermis of the fruit first develops a young cellule, which by partition is resolved into the stalk-cell and the true mother-cell of the small clavate resin-cellules. At first, the contents of the latter do not differ from the mass in which they are imbedded, and perhaps pass gradually into resin by metamorphosis of the cellular substance.

The glands of kamala are always accompanied by colourless or brownish, thick-walled, stellate hairs, two or three times as long as the glands, often containing air, which do not exhibit any peculiarity of form, but resemble the hairs of other plants, as Verbascum or Althæa.

Chemical Composition—Kamala has been analysed by Anderson of Glasgow (1855) and by Leube (1860). From the labours of these chemists, it appears that the powder yields to alcohol or ether nearly 80 per cent. of resin. We find it to be soluble also in glacial acetic acid or in bisulphide of carbon, not in petroleum ether. By treatment of the resin extracted by ether with cold alcohol, Leube resolved it into two brittle reddish yellow resins, of which the one is more easily soluble and fuses at 80° C., and the other dissolves less readily and fuses at 191°. Both dissolve in alkaline solutions, and can be precipitated by acids without apparent change.

Anderson found that a concentrated ethereal solution of kamala allowed to stand for a few days, solidified into a mass of granular crystals, which by repeated solution and crystallization in ether were obtained in a state of purity. This substance, named by Anderson Rottlerin,[2139] forms minute, platy, yellow crystals of a fine satiny lustre, readily soluble in ether, sparingly in cold alcohol, more so in hot, and insoluble in water. The mean of four analyses gave the composition of rottlerin as C₂₂H₂₀O₆.

We have been able to confirm the foregoing observations so far as that we have obtained an abundance of minute acicular crystals, by allowing an ethereal solution of kamala to evaporate spontaneously to a syrupy state. But the purification of these crystals, which was also attempted by our friend Mr. T. B. Groves,[2140] was unsuccessful, for when freed from the protecting mother-liquor, they underwent a change and assumed an amorphous form. We have, on the other hand, succeeded in isolating the crystals from the “Kamalin,” as sold by E. Merck of Darmstadt. By fusing them with caustic potash we obtained paraoxy-benzoic acid (see page 408).

Uses—The drug is administered for the expulsion of tapeworm; it has also been used as an external application in herpes circinnatus. In India it is employed for dyeing silk a rich orange-brown.

Adulteration—Kamala is very liable to adulteration with earthy substances, even to the extent of 60 per cent. This contamination may easily be known by the grittiness of the drug, and by a portion of it sinking when it is stirred up with water, but in the most decisive manner by incineration. Sometimes kamala contains an undue proportion of foreign vegetable matter, as remains of the capsules, leaves, etc., which can partly be separated by a lawn sieve. We have met with a large quantity of very impure Kamala in the London market (1878), which was offered for cleaning polished metallic surfaces.

Substitute—A very remarkable form of so-called kamala was imported in 1867 from Aden by Messrs. Allen and Hanburys, druggists, of London.[2141] It arrived neatly packed in oblong, white calico bags, of three sizes, each inscribed with Arabic characters, indicating with the name of the vendor or collector, a native of Hurrur, the net weight, which was either 100, 50, or 25 Turkish ounces. No more than two supplies, in all 136 lb., could be obtained.

The drug was in coarser particles than kamala, of a deep purple, and had a distinct odour resembling that which is produced when a tincture of kamala is poured into water. It had been carefully collected and was free from earthy admixture, yet it left upon incineration 12 per cent. of ash. Under the microscope it presented still greater differences, the grains being cylindrical or subconical, 170 to 200 mkm. long, by 70 to 100 mkm. broad, with oblong resin-cells, arranged perpendicularly in three or four storeys; mixed with the grains were a few long, simple hairs. Another fact of some interest is, that at a temperature of 93° to 100° C., this drug becomes quite black, while kamala undergoes no change of colour.

In 1878 our friend Professor Schär was informed by a Swiss firm, Messrs. Furrer and Escher of Aden, that Kanbil, Qinbil or Kamala are unknown there. But they sent under the name of Vars a powder, which Prof. Schär as well as one of us (F.) find identical with the drug which had been imported by Messrs. Allen and Hanbury. Prof. Schär was also informed that Vars is used chiefly in the coast districts of Mascat (Oman) and Hadramaut, in skin diseases, for expelling the tape worm and as a dye.

Thus the appellation Wurrus or Waras is to be restricted to the dark purple or violet glands occurring in eastern Africa and Yemen, although the Waras sent to one of us[2142] by Vaughan was kamala.

As to the mother plant of Waras[2143] we have no information to offer; we attempted in vain to ascertain its origin. It is evident that it is the “black Abyssinian” powder already alluded to at page 573.