CONVOLVULACEÆ.

SCAMMONIUM.

Scammony; F. Scammonée; G. Scammonium.

Botanical OriginConvolvulus Scammonia L., a twining plant much resembling the common C. arvensis of Europe, but differing from it in being of larger size, and having a stout tap-root. It occurs in waste bushy places in Syria, Asia Minor, Greece, the Greek Islands, extending northward to the Crimea and Southern Russia, but appears to be wanting in Northern Africa, Italy, and in all the western parts of the Mediterranean basin.

History—The dried milky juice of the scammony plant has been known as a medicine from very ancient times. Theophrastus in the 3rd century b.c. was acquainted with it; it was likewise familiar to Dioscorides, Pliny, Celsus, and Rufus of Ephesus, each of whom has given some account of the manner in which it was collected. Scammony used then also to be called Diagrydion, from the Greek word δάκρυ, tear. The mediæval Arabian physicians also knew scammony and the plant from which it is derived. The drug was used in Britain in the 10th and 11th centuries, and would appear to be one of the medicines recommended to King Alfred the Great, by Helias, patriarch of Jerusalem.[1625] It is repeatedly named in the medical writings in use prior to the Norman conquest (a.d. 1066), in one of which directions are given for recognizing the goodness of the drug by the white emulsion it produces when wetted.

The botanists of the 16th and 17th centuries, as Brunfels, Gesner, Matthiolus, Dodonæus, and the Bauhins, described and figured the plant partly under the name of Scammonia syriaca. The collecting of the drug was well described by Russell, an English physician of Aleppo (1752), whose account[1626] is accompanied by an excellent figure representing the plant and the means of obtaining its juice.

Scammony was formerly distinguished by the names Aleppo and Smyrna, the former sort being twice or thrice as costly as the latter; at the present day Aleppo scammony has quite lost its pre-eminence.

Localities producing the drug—Scammony is collected in Asia Minor, from Brussa and Boli in the north, to Macri and Adalia in the south, and eastward as far as Angora. But the most productive localities within this area are the valley of the Mendereh, south of Smyrna: and the districts of Kirkagach and Demirjik, north of that town. The neighbourhood of Aleppo likewise affords the drug. A little is obtained further south in Syria, from the woody hills and valleys about the lake of Tiberias and Mount Carmel.

Production—The scammony plant has a long woody root, which throws off downwards a few lateral branches, and produces from its knotty summit numerous twining stems which are persistent and woody at the base. In plants of three or four years old, the root may be an inch or more in diameter; in older specimens it sometimes acquires a diameter of three or four inches. In length, it is from two to three feet, according to the depth of soil in which it grows. When the root is wounded, there exudes a milky juice which dries up to a golden-brown, transparent, gummy-looking substance:—this is pure scammony.[1627]

The method followed in collecting scammony for use appears to be nearly the same in all localities. It has been thus described to us by two eye-witnesses, both long resident in the East.[1628] Operations commence by clearing away the bushes among which the plant is commonly found; the soil around the latter is then removed, so as to leave 4 or 5 inches of the root exposed. This is then cut off in a slanting direction at 2 to 4 inches below the crown, and a mussel-shell is stuck into it just beneath the lowest edge, so as to receive the milky-sap which instantly flows out. The shells are usually left till evening, when they are collected, and the cut part of the root scraped with a knife, so as to remove any partially dried drops of juice. These latter are called by the Smyrna peasants, kaimak or cream, the softer contents of the shell being called gala or milk.

Sometimes the scammony is allowed to dry in the shell, and such must be regarded as representing the drug in its utmost perfection. But scammony in shells is not brought into commerce, though a little of it is reserved by the peasants for their own use.

The contents of the shells and the scraped off drops are next emptied into a covered copper pot or a leathern bag, carried home, made homogenous by mixing with a knife, and at once allowed to dry. In this way a form of scammony is obtained closely approaching that dried in the shell. But it is a quality of exceptional goodness. Usually the peasant does not dry off the juice promptly, but allows his daily gatherings to accumulate; and when he has collected a pound or two, he places it in the sunshine to soften, and then kneads it, sometimes with the addition of a little water, into a plastic mass, which he lastly allows to dry. By this long exposure to heat, and retention in a liquid state, the scammony juice undergoes fermentation, acquires a strong cheesy odour and dark colour, and when finally dried, exhibits a more or less porous or bubbly structure, never observable in shell scammony.

Scammony is very extensively adulterated. The adulteration is often performed by the peasants, who mix foreign substances into the drug while it is yet soft; and it is also effected by the dealers, some of whom purchase it of the peasants in a half-dried state. The substances used for sophistication are numerous, the commonest and most easily detected being, according to our experience, carbonate of lime and flour. Woodashes, earth (not always calcareous), gum arabic, and tragacanth are also employed; more rarely, wax, yolk of egg, pounded scammony roots, rosin, or black-lead.

Description—The pure juice of the root, simply dried by exposure to the sun and air, is an amorphous, transparent, brittle substance, of resinous aspect, a yellowish-brown colour, and glossy fracture. Scammony possessing these characters is occasionally met with in the form of flattish irregular masses, about ½ to ¾ of an inch in thickness, very brittle by reason of internal fissures, yet with but few air-cavities. In mass, it is of a chesnut-brown, but in small fragments it is seen to be very pale yellowish-brown and transparent, with the freshly fractured surface vitreous and shining. When powdered it is of a very light buff. Rubbed with the moistened finger it forms a white emulsion. Treated with ether it yields 88 to 90 per cent. of soluble matter, and a nearly colourless residuum. This scammony, as well as the pure juice in the shell, is very liable to become mouldy; but besides this, it throws out, if long kept, a white, mammillated, crystalline efflorescence, the nature of which we have not been able to determine. But if scammony is kept quite dry, neither mouldiness nor efflorescence makes its appearance.

The ordinary fine scammony of commerce, known as Virgin Scammony, is also in large flat pieces or irregular flattened lumps and fragments, which in mass have a dark grey or blackish hue. Viewed in thin fragments, it is seen to be translucent and of a yellowish-brown. It is very easily broken, exhibits a shining fracture, gives an ashy-grey powder, and has a peculiar cheesy odour. Some of the pieces have a porous, bubbly structure, indicative of fermentation; the more solid often show the efflorescence already mentioned. Scammony has not much taste, but leaves an acrid sensation in the throat.

Chemical Composition—Scammony owes its active properties as a medicine to a resin shown (1860) by Spirgatis to be identical with that found in the root of the Mexican Ipomœa orizabensis, known in commerce as Male Jalap: this resin called Jalapin will be described in the next article. The other constituents of pure scammony are not well known. One of them is the substance which, as already stated, makes its appearance as small masses of cauliflower crystals on the surface of pure scammony, when the latter is kept in air not perfectly dry.

Whether the odour observable in commercial scammony is due to a volatile fatty acid developed by fermentation, is a question still to be investigated.

Commerce—The export of scammony from Smyrna amounted in 1871 to 278 cases, valued at £8320; in 1872 to 185 cases, value £6100. According to a report of Consul Skene on the trade of Northern Syria,[1629] 737 cases of scammony were exported from the province of Aleppo in 1872,—six-sevenths of the quantity being for England. In 1873 Aleppo exported by way of Alexandretta to England 46,500 kilogrammes of scammony root and 900 kilogrammes of the resin, the latter being valued at 36,000 francs (£1444).

An establishment at Brussa, founded by Della Sudda, of Constantinople, is stated to export since 1870 a very good scammony resin extracted by alcohol.[1630]

Uses—Employed as an active cathartic, often in combination with colocynth and calomel.

Adulteration—Scammony is very often imported in an adulterated state, but the adulteration is so clumsily effected, and is so easily discoverable by simple tests, or even by ocular examination, that druggists have but little excuse for accepting a bad article.

We have already named the substances used in the sophistication of scammony: of these, the most frequent are carbonate of lime and farinaceous matter. The first may generally be recognized by examining the fractured surface of the drug with a good lens, when the white particles of the carbonate will be perceived. If the surface is then touched (while still sub lente) with hydrochloric acid, effervescence will prove the presence of a carbonate. Other earthly adulterants can be discovered by incineration, or by examining the residue of the drug after treatment with ether. Starchy substances, the presence of which may be surmised by the scammony being difficult to break, are detectable by the microscope or by solution of iodine, a cold decoction of scammony not being affected by that reagent. Scammony that is ponderous, dull and clayey, not easily broken in the fingers, or which when broken does not exhibit a clean, glossy surface, or which does not afford at least 80 per cent. of matter soluble in ether, should be rejected. That which is made up in the form of hard, dark, circular cakes is widely different from pure scammony.

Scammony may be distinguished from Resin of Scammony by its property of forming an emulsion when wetted. The resin is also more glossy and almost entirely soluble in ether.

Radix Scammoniæ.

The frauds commonly practised on the scammony of commerce have given rise to various schemes for obtaining the drug in a purer form, as well as at a more moderate price.[1631]

So far back as 1839, the Edinburgh College prescribed a Resina Scammonii, which was prepared by exhausting scammony with a spirit of wine, distilling off the spirit, and washing the residue with water. Such an extract was manufactured by the late Mr. Maltass of Smyrna, and occasionally shipped to London.

In consequence of a suggestion made by Mr. Clark, manufacturer of liquorice at Sochia near Scala Nuova, south of Smyrna, a patent was taken out (1856) by Prof. A. W. Williamson of London, for preparing this resin directly from the dried root by means of alcohol. The same chemist shortly afterwards devised an improved process, which consists in boiling the roots first with water and then with dilute acid, so as to deprive them of all matters soluble in those menstrua, and afterwards extracting the resin by alcohol.

Resin of Scammony, obtained either from scammony or from the dried root, is ordered in the British Pharmacopœia of 1867, and is manufactured by a few houses. It is a brown, translucent, brittle substance of resinous fracture, entirely soluble in ether, and not forming an emulsion when wetted with water.

Scammony root is occasionally brought into the London market, sometimes in rather large quantity,[1632] but it is not generally kept by druggists, nor do we find it quoted in price-currents. Its collection is even opposed in some parts of Turkey by the local authorities.[1633]

The root consists of stout, woody, cylindrical pieces, often spirally twisted, 2 to 3 inches in diameter, covered with a rough, furrowed, greyish-brown bark. They are internally pale brown, tough and resinous, with a faint odour and taste resembling jalap. A good sample yielded us 5½ per cent. of resin; Kingzett and Farries (1877) showed the root to be devoid of an alkaloid.

RADIX JALAPÆ.

Tuber Jalapæ; Jalap, Vera Cruz Jalap; F. Racine de Jalap; G. Jalape.

Botanical OriginIpomœa Purga Hayne (Convolvulus Purga Wenderoth, Exogonium Purga Bentham), a tuberous-rooted plant, throwing out herbaceous, twining stems, clothed with cordate-acuminate sharply auricled leaves, and bearing elegant salver-shaped, deep pink flowers. It grows naturally on the eastern declivities of the Mexican Andes, at an elevation above the sea of 5000 to 8000 feet, especially about Chiconquiaco and the adjacent villages, and also around San Salvador on the eastern slope of the Cofre de Perote. In these localities where rain falls almost daily, and where the diurnal temperature varies from 15° to 24° C. (60° to 75° F.), the plant occurs in shady woods, flourishing in a deep rich vegetable soil.

The jalap grows freely in the south of England, if planted in a sheltered border, but its flowers are produced so late in autumn that they rarely expand, and the tubers, which develope in some abundance, are liable to be destroyed in winter unless protected from frost.

The plant has been introduced on the Neilgherry Hills in the south of India; it succeeds there remarkably well,[1634] and might be extensively propagated if there were any adequate inducement.

History—The use as a purgative of the tuber of a convolvulaceous plant of Mexico, was made known by the early Spanish voyagers; and so highly was the new drug esteemed that large quantities of it reached Europe during the 16th century.

Monardes, writing in 1565, says the new drug was called Ruybarbo de las Indias or Ruybarbo de Mechoacan, the latter name being given in allusion to the province of Michoacan whence the supplies were derived. Some writers have advanced the opinion that mechoacan root was the modern jalap, but in this we do not concur, for the description given of mechoacan and the place of its production do not apply well to jalap. Both drugs were moreover well known about 1610; they were perfectly distinguished by Colin, an apothecary of Lyons (1619), who mentions jalap (“racine de Ialap”) as then newly brought to France.[1635] They were however often confounded, or at least only distinguished by their difference of tint. Thus jalap, which at that period used to be imported cut into transverse slices,[1636] was termed, from its darker colour, Black Mechoacan; and on the other hand, the paler mechoacan was in later times known as White Jalap.

Mechoacan root is now known to consist (at least in part) of the large thick tuber of Ipomœa Jalapa Pursh (Batatas Jalapa Choisy), a plant of the Southern United States and Mexico. As a drug it has been long obsolete in Europe, having given place to jalap, which is a more active and efficient purgative.

The botanical source of jalap was not definitely ascertained until about the year 1829, when Dr. Coxe of Philadelphia published a description and coloured figure, taken from living plants sent to him two years previously from Mexico.[1637]

Manner of Growth—Though we have cultivated the jalap plant for many years, we have had no opportunity of examining the seedling, but judging from analogy suppose that it has at first a small tap-root which gradually thickens after the manner of a radish. A root of jalap, called by some tuber and by others tubercule, throws out in addition to aerial stems, slender, prostrate, underground shoots which emit roots at intervals. These roots while but an inch or two long become thickened and carrot-shaped, gradually enlarging into napiform tuber-like bodies, which emit a few rootlets from their surface and taper off below in long, slender ramifications. The thickened roots have no trace of leaf-organs; the aerial stems grow from the shoot from which they originated.

Fresh jalap roots (tubers) are externally rough and dark brown, internally white and fleshy.

Collection—Jalap is said to be dug up in Mexico during the whole year.[1638] The smaller roots are dried entire; the larger are cut transversely, or are gashed so that they may dry more easily. As drying by sun-heat would be almost impracticable owing to the wetness of the climate, the roots are placed in a net, and suspended over the almost constantly burning hearth of the Indian’s hut, where they gradually dry, and at the same time often contract a smoky smell. Much of the jalap that has of late arrived has been more freely sliced than usual, and has obviously been dried with less difficulty.

According to Schiede, whose account was written in 1829,[1639] the Indians of Chiconquiaco were at that period commencing the cultivation of jalap in their gardens.

Description—The jalap of commerce consists of irregular, ovoid roots, varying from the size of an egg to that of a hazel-nut, but occasionally as large as a man’s fist. They are usually pointed at the lower end, deeply wrinkled, contorted and furrowed, and of a dark brown hue, dotted over with numerous little, elongated, lighter coloured scars, running transversely. The large roots are incised lengthwise, or cut into halves or quarters, but the smaller are usually entire. Some of the small roots are spindle-shaped or cylindrical; others can be found which are nearly globular, smooth and pitchy-looking, but these latter are seldom solid. Good jalap is ponderous, tough, hard and often horny, becoming brittle when long kept, and breaking with a resinous non-fibrous fracture; internally it is of a pale dingy brown or dirty white. It has a faint smoky, rather coffee-like odour, and a mawkish taste, followed by acridity.

Microscopic Structure—Seen in transverse section, jalap exhibits no radiate structure, but numerous small concentric rings, which in many pieces are very regularly arranged. They are due to the laticiferous cells, differing from the surrounding parenchyme only by their contents and rather large size. These laticiferous cells traverse the tissue in a vertical direction, constituting vertical bands, as may be observed on a longitudinal section; the single cells are simply placed one on the other, and do not form elongated ducts as in Lactuca or Taraxacum.

The fibro-vascular bundles of jalap are neither numerous nor large; they are accompanied by thin-walled cells, so that firm woody rays do not occur. Parenchymatous cells are abundant, and, on a longitudinal fracture especially, if subsequently moistened, are seen to constitute concentric layers. The laticiferous cells are always found in the outer part of each layer. The suberous coat with which the drug is covered is made up of the usual tabular cells.

The parenchyme of jalap is loaded with starch grains; in the pieces which have been submitted to heat in order to dry them, the starch appears as an amorphous mass, and the drug then exhibits a horny consistence and greyish fracture, instead of being mealy. Crystals of calcium oxalate are frequently met with. The laticiferous cells contain the resin of jalap in a semi-fluid state, even in the dry drug; drops of the resinous emulsion flow out of the cells, if thin slices are moistened by any watery liquid.

Chemical Composition—Jalap owes its medicinal efficacy to a resin, which is extractable by exhausting the drug with spirit of wine, concentrating the alcoholic solution to a small bulk, and pouring it into water. The resin precipitated in this manner is then washed and dried; it is contained in jalap to the extent of 12 to 18 per cent.[1640]

From this crude resin, which is the Resina jalapæ of the pharmacopœias, ether or chloroform extracts 5 to 7 (12, Umney) per cent. of a resin which, according to Kayser,[1641] partially solidifies when in contact with water in crystalline needles. We can by no means confirm Kayser’s statement. The residue (insoluble in ether) is one of the substances to which the name Jalapin has been applied.[1642] W. Mayer, 1852-1855, who designated it Convolvulin,[1643] found it to have the composition C₃₁H₅₀O₁₆. When purified, it is colourless; it dissolves easily in ammonia as well as in the fixed alkalis, and is not re-precipitated by acids, having been converted by assumption of water into amorphous Convolvulic Acid, which is readily soluble in water. Both convolvulin and convolvulic acid are resolved by moderate heating with dilute acids, or with emulsin, into crystallizable Convolvulinol, C₂₆H₅₀O₇, and sugar. Convolvulinol in contact with aqueous alkalis is converted into Convolvulinolic Acid, C₂₆H₄₈O₆, which is slightly soluble in water and crystallizable.

When convolvulin or its derivatives is treated with nitric acid, it yields several acids, one of which is the Sebacic Acid,

C₈H₁₆ COOH
COOH,

which is to be obtained by treating castor oil or other fatty substances in the same manner. Sebacic acid forms crystalline scales, soluble in boiling water, melting at 128°. That from jalap was first thought to be a peculiar acid, and therefore termed ipomic or ipomœic acid. Its identification is due to Neison and Bayne (1874).

Convolvulin (dry) melts at 150° C., but a small amount of water renders it fusible below 100° C. It is insoluble in oil of turpentine and in ammonia. It dissolves in dilute nitric acid without becoming coloured or evolving gas. Convolvulin possesses in a high degree the purgative property of jalap, but this is not the case with convolvulinol.

The other constituents of jalap include starch, uncrystallizable sugar, gum, and colouring matter. The sugar, according to Guibourt, exists to the extent of 19 per cent.

Commerce—We have no means of knowing to what extent jalap is produced in Mexico. The imports of the drug into the United Kingdom amounted in 1870 to 169,951 lb. Very considerable quantities have of late (1873) appeared in the London drug-sales.

Uses—Jalap is employed as a brisk cathartic.

Other kinds of Jalap.

Besides true jalap, the roots of certain other Convolvulaceæ of Mexico have been employed in Europe, either in the form of jalapin, or as adulterants of the more costly, legitimate drug. The two following have been extensively imported and have been traced to their botanical source; but there are others, of more occasional occurrence, the origin of which has not been ascertained.[1644]

1. Light, Fusiform, or Woody Jalap, Male Jalap, Orizaba Root, Jalap Tops or Stalks, Purgo macho of the Mexicans.

This drug is derived from Ipomœa orizabensis Ledanois,[1645] a plant of Orizaba, which is but imperfectly known. It is described as a pubescent climber, having a spindle-shaped root about two feet long of woody and fibrous texture. The drug occurs in irregular rectangular or block-like pieces, evidently portions of a very large root, divided transversely and longitudinally. Sometimes it is more like true jalap, being in entire roots, of smaller size, spindle-shaped, not spherical. It has a somewhat lighter colour than jalap, and much deeper longitudinal wrinkles. The larger pieces often exhibit deep cuts from an axe or knife; transverse slices are of rare occurrence. Although generally less ponderous than jalap, the Orizaba drug is nevertheless of a compact and often horny texture. From jalap it is easily distinguished by its radiated transverse section, and the numerous thick bundles of vessels which project as woody fibres from the fractured surface.

In chemical constitution Orizaba root is closely parallel to jalap. The resin was named by Mayer Jalapin; it is the Jalapin of Gmelin’s Chemistry (xvi. 405), and perhaps the jalapin of English pharmacy.[1646]

In the pure state it is a colourless amorphous translucent resin, dissolving perfectly in ether,[1647] thus differing from convolvulin the corresponding resin of jalap. We find that it is readily soluble also in acetone, amylic alcohol, benzol and phenol, not in bisulphide of carbon. It has the composition of C₃₄H₅₆O₁₆, so that it is homologous with convolvulin; the decomposition-products of jalapin obtained by similar treatment, namely jalapic acid, jalapinol, and jalapinolic acid, are likewise homologous with the corresponding substances obtained from convolvulin. All these bodies when treated with nitric acid yield ipomœic acid. Jalapin has the same fusing point as convolvulin, and behaves in the same manner with alkalis.

The root afforded us 11·8 per cent. of resin dried at 100° C. When perfectly washed, decolorized and dissolved in two parts of alcohol, this resin turned the plane of polarization of a ray of light 9·8° to the left, in a column of 50 mm. long. Convolvulin under the same conditions turned it only 5·8°. The resin of Orizaba root is held by chemists to be identical with that of scammony, of which it has the drastic action.

2. Tampico Jalap,—Purga de Sierra Gorda of the Mexicans. The plant which affords this drug has been described by one of us (1869) under the name of Ipomœa simulans.[1648] It is closely related to I. Purga Hayne, from which by its foliage it cannot be distinguished, but it has a bell-shaped corolla and pendulous flower-buds, which are very different. I. simulans Hanbury grows in Mexico along the mountain range of the Sierra Gorda in the neighbourhood of San Luis de la Paz, from which town and the adjacent villages its roots are carried down to Tampico. It has also been found on the lofty Cordillera near Oaxaca, but whether there collected we know not.

The drug, to which in trade the name Tampico Jalap is commonly applied, has been imported during the last few years in considerable quantities. In appearance it closely approaches true jalap, but the roots are generally smaller, more elongated or finger-like, more shrivelled and corky-looking, wanting in the little transverse scars that are plentifully scattered over the roots of true jalap. Many pieces occur however which it is impossible to distinguish by the eye from true jalap, with which it agrees also in odour and taste.

Tampico jalap yielded to one of us 10 per cent. of purified resin, entirely soluble in ether. Umney[1649] obtained 12 to 15 per cent. of resin almost wholly soluble in ether; Evans got 13 per cent., but found only about half of this to be soluble in ether.[1650] According to Andouard[1651] the resin of Tampico jalap is not deficient in purgative powers.

SEMEN KALADANÆ.

Semen Pharbitidis; Kaladana.

Botanical OriginIpomœa Nil[1652] Roth (Pharbitis Nil Choisy, Convolvulus Nil L.), a twining annual plant, with a large blue corolla, much resembling the Major Convolvulus (Pharbitis hispida Choisy) of English gardens, but having three-lobed leaves.[1653] It is found throughout the tropical regions of both hemispheres, and is common in India, ascending the mountains to a height of 5000 feet.

History—The seeds of this plant were employed in medicine by the Arabian physicians under the name Habbun-nil; and they have probably been long in use among the natives of Hindustan. In recent times they have been recommended by O’Shaughnessy, Kirkpatrick, Bidie, Waring[1654] and many other European practitioners in India as a safe and efficient cathartic.

Description—The shape of the seeds is that which would result if a nearly spherical body were divided perpendicularly around its axis into 6 or 8 almost equal segments, only that the back is less regularly vaulted. The seeds are ¼ of an inch high and nearly as much broad; 100 of them weigh on an average about 6 grammes. There is a smaller variety imported from Calcutta, of which 100 seeds weigh but little over 3 grammes; in every other respect the two sorts are identical. Both are of a dull black, excepting at the umbilicus, which is brown and somewhat hairy. The adjacent parts of the thin shell (testa) crack in various directions, if the seed is kept for a short time in cold water. If it is removed from the upper part of the vaulted back, the radicle becomes visible, surrounded by the undulated folds of the cotyledons, which join perpendicularly, but cannot be easily unfolded by reason of the thin seminal integument. Cut transversely, the cotyledons show the same curled structure. Throughout their tissue, small bright glands in considerable number are observable, even without a lens. The kernel, which is devoid of albumen, has at first a nutty taste, with subsequently a disagreeable persistent acridity. When bruised in a mortar, the seeds evolve a heavy earthy smell.

Microscopic Structure—The seed is covered with a dark blackish cuticle, formed of a densely packed tissue, the cells of which show zigzag outlines. The dark brown epidermis is composed of very close cylindrical cells, about 70 mkm. in length and 5 to 7 mkm. in diameter; they require to be treated with chromic acid in order that their structure may be distinctly seen.

The tissue of the kernels is made up of thick-walled cells. Between this tissue and the shell there is a colourless layer, about 70 mkm. thick, of thin-walled corky parenchyme. The cotyledons contain in their narrow tissue numerous granules of albuminous matter, mucilage, a little tannic acid, crystals of oxalate of calcium, and a few starch granules. The glands or hollows, before alluded to as occurring throughout the tissue of the cotyledons, are about 70 mkm. in diameter, and contain an oily liquid.

Chemical Composition—By exhausting the seeds dried at 100° C. with boiling ether, we obtained a thick light brownish oil having an acrid taste and concreting below 18° C. The powdered seeds yielded of this oil 14·4 per cent. Water removes from the seeds a considerable amount of mucilage, some albuminous matter and a little tannic acid. The first is soluble to some extent in dilute spirit of wine, and may be precipitated therefrom by an alcoholic solution of acetate of lead.

The active principle of kaladana is a resin, soluble in alcohol, but neither in benzol nor in ether. From the residue of the seeds after exhaustion by ether, treatment with absolute alcohol removed a pale yellowish resin in quantity equivalent to 8·2 per cent. of the seed.

Kaladana resin, which has been introduced into medical practice in India under the name of Pharbitisin,[1655] has a nauseous acrid taste and an unpleasant odour, especially when heated. It melts about 160° C. The following liquids dissolve it more or less freely, namely, spirit of wine, absolute alcohol, acetic acid, glacial acetic acid, acetone, acetic ether, methylic and amylic alcohol, and alkaline solutions. It is on the other hand insoluble in ether, benzol, chloroform, and sulphide of carbon. With concentrated sulphuric acid, it forms a brownish yellow solution, quickly assuming a violet hue. This reaction however requires a very small quantity of the powdered resin. If a solution of the resin in ammonia, after having been kept a short time, is acidulated, no precipitate is formed; but the solution is now capable of separating protoxide of copper from an alkaline solution of the tartrate, which originally it did not alter. Heated with nitric acid, the resin affords sebacic acid (see p. 446).

From these reactions of kaladana resin, we are entitled to infer that it agrees with the resin of jalap or Convolvulin. To prepare it in quantity, it would probably be best to treat the seeds with common acetic acid, and to precipitate it by neutralizing the solution. We have ascertained that the resin is not decomposed when digested with glacial acetic acid at 100° C., even for a week.

We have had the opportunity of examining a sample of kaladana resin manufactured by Messrs. Rogers and Co., chemists of Bombay and Poona, which we found to agree with that prepared by ourselves. It is a light yellowish friable mass, resembling purified jalap resin, and like it, capable of being perfectly decolorized by treatment with animal charcoal.

Uses—Kaladana seeds have cathartic powers like jalap. Besides the resin, an extract, tincture and compound powder have been introduced into the Pharmacopœia of India. In many parts of India the natives take the roasted seeds as a purgative.