TRAGACANTHA
Gummi Tragacantha; Tragacanth, Gum Tragacanth; F. Gomme Adragante; G. Traganth.
=Botanical Origin.=—Tragacanth is the gummy exudation from the stem of several pieces of Astragalus, belonging to the subgenus Tragacantha. The plants of this group are low perennial shrubs, remarkable for their leaves having a strong, persistent, spiny petiole. As the leaves and shoots are very numerous and regular, many of the species have the singular aspect of thorny hemispherical cushions, lying close on the ground; while others, which are those furnishing the gum, grow erect with a naked woody stem, and somewhat resemble furze bushes.
A few species occur in South-western Europe, others are found in Greece and Turkey; but the largest number are inhabitants of the mountainous regions of Asia Minor, Syria, Armenia, Kurdistan and Persia. The tragacanth of commerce is produced in the last named countries, and chiefly, though not exclusively, by the following species[704]:—
1. Astragalus adscendens Boiss. et Hausskr., a shrub attaining 4 feet in height, native, of the mountains of South-western Persia at an altitude of 9,000 to 10,000 feet. According to Haussknecht, it affords an abundance of gum.
2. A. leioclados Boiss.
3. A. brachycalyx Fisch., a shrub of 3 feet high, growing on the mountains of Persian Kurdistan, likewise affords tragacanth.
4. A. gummifer Labill., a small shrub of wide distribution occurring on the Lebanon and Mount Hermon in Syria, the Beryt Dagh in Cataonia, the Arjish Dagh (Mount Argæus) near Kaisariyeh in Central Asia Minor, and in Armenia and Northern Kurdistan.
5. A. microcephalus Willd., like the preceding a widely distributed species, extending from the south-west of Asia Minor to the north-east coast, and to Turkish and Russian Armenia. A specimen of this plant with incisions in the stem, was sent some years ago to the Pharmaceutical Society by Mr. Maltass of Smyrna. We received a large example of the same species, the stem of which is marked by old incisions, from the Rev. W. A. Farnsworth of Kaisariyeh, who states that tragacanth is collected from it on Mount Argæus.
6. A. pycnocladus Boiss. et Haussk., nearly related to A. microcephalus; it was discovered on the high mountains of Avroman and Shahu in Persia by Professor Haussknecht, who states that it exudes tragacanth in abundance.
7. A. stromatodes Bunge, growing at an elevation of 5,000 feet on the Akker Dagh range, near Marash in Northern Syria.
8. A. kurdicus Boiss., a shrub 3 to 4 feet high, native of the mountains of Cilicia and Cappadocia, extending thence to Kurdistan. Haussknecht has informed us that from this and the last named species, the so-called Aintab Tragacanth is chiefly obtained.
[704] As described in Boissier’s Flora Orientalis, ii. (1872). We have to thank Professor Haussknecht of Weimar for revising our list of species, and for some valuable information as to the localities in which the drug is produced.
Probably the drug is also to some extent collected from
9. A. verus Olivier, in North-western Persia and Asia Minor.
Lastly as to Greece, tragacanth is also afforded by
10. A. Parnassi Boiss., var. cyllenea, a small shrub found in abundance on the northern mountains of the Morea, which is stated by Heldreich[705] to be the almost exclusive source of the tragacanth collected about Vostizza and Patras.
=History=—Tragacanth has been known from a very early period. Theophrastus in the 3rd century B.C. mentioned Crete, the Peloponnesus and Media as its native countries. Dioscorides, who as a native of South-eastern Asia Minor was probably familiar with the plant, describes it correctly as a low spiny bush. The drug is mentioned by the Greek physicians Oribasius, Aëtius, and Paulus Ægineta (4th to 7th cent.), and by many of the Arabian writers on medicine. The abbreviated form of its name “Dragantum” already occurs in the book “Artis veterinariæ, seu mulomedicinæ” of Vegetius Renatus, who lived about A.D. 400. During the middle ages the gum was imported into Europe through the trading cities of Italy, as shown in the statutes of Pisa,[706] A.D. 1305, where it is mentioned as liable to impost.
Pierre Belon, the celebrated French naturalist and traveller, saw and described, about 1550, the collecting of tragacanth in the northern part of Asia Minor; and Tournefort in 1700 observed on Mount Ida in Candia the singular manner in which the gum is exuded from the living plant.[707]
=Secretion=—It has been shown by H. von Mohl[708] and by Wigand[709] that tragacanth is produced by metamorphosis of the cell membrane, and that it is not simply the dried juice of the plant.
The stem of a gum-bearing Astragalus cut transversely, exhibits concentric annual layers which are extremely tough and fibrous, easily tearing lengthwise into thin filaments. These inclose a central column, radiating from which are numerous medullary rays, both of very singular structure, for instead of presenting a thin-walled parenchyme, they appear to the naked eye as a hard translucent gum-like mass, becoming gelatinous in water. Examined microscopically, this gummy substance is seen to consist not of dried mucilage, but of the very cells of the pith and medullary rays, in process of transformation into tragacanth. The transformed cells, if their transformation has not advanced too far, exhibit the angular form and close packing of parenchyme-cells, but their walls are much incrassated and evidently consist of numerous very thin strata.
That these cells are but ordinary parenchyme-cells in an altered state, is proved by the pith and medullary rays of the smaller branches which present no such unusual structure. Mohl was able to trace this change from the period in which the original cell membrane could be still easily distinguished from its incrusting layers, to that in which the transformation had proceeded so far that it was impossible to perceive any defined cells, the whole substance being metamorphosed into a more or less uniform mucilaginous mass.
[705] Nutzpflanzen Griechenlands, Athen, 1862. 71.
[706] Bonaini, Statuti inediti della città di Pissa dal xii. al xiv. secolo, iii. (1857) 106. 114.
[707] Voyage into the Levant, Lond. (1718) 43.
[708] Botanische Zeitung, 1857. 33; Pharm. Journ. xviii. (1859) 370.
[709] Pringsheim’s Jahrbücher f. wissenchaftl. Botanik, iii. (1861) 117.
The tension under which this peculiar tissue is held in the interior of the stem is very remarkable in Astragalus gummifer which one of us had the opportunity of observing on the Lebanon in 1860.[710] On cutting off a branch of the thickness of the finger, there immediately exudes from the centre a stream of soft, solid tragacanth, pushing itself out like a worm, to the length of ¾ of an inch, sometimes in the course of half an hour; while much smaller streams (or none at all) are emitted from the medullary rays of the thick bark.
=Production=—The principal localities in Asia Minor in which tragacanth is collected are the district of Angora, the capital of the ancient Galatia; Isbarta, Buldur and Yalavatz,[711] north of the gulf of Adalia; the range of the Ali Dagh between Tarsous and Kaisariyeh, and the mountainous country eastward as far as the valley of the Euphrates. The drug is also gathered in Armenia on the elevated range of the Bingol Dagh south of Erzerum; throughout Kurdistan from Mush for 500 miles in a south-eastern direction as far as the province of Luristan in Persia, a region including the high lands south of lake Van, and west of lake Urumiah. It is likewise produced in Persia farther east, over an area 300 miles long by 100 to 150 miles broad, between Gilpaigon and Kashan, southward to the Mahomed Senna range north-east of Shiraz, thus including the lofty Bakhtiyari mountains.
As to the way in which the gum is obtained, it appears from the statements of Maltass, that in July and August the peasants clear away the earth from around the stem of the shrub, and then make in the bark several incisions, from which during the following 3 or 4 days the gum exudes and dries in flakes. In some localities they also puncture the bark with the point of a knife. Whilst engaged in these operations, they pick from the shrubs whatever gum they find exuded naturally.
Hamilton,[712] who saw the shrub in 1836 on the hills about Buldur, says “the gum is obtained by making an incision in the stem near the root, and cutting through the pith, when the sap exudes in a day or two and hardens.”
Formerly the peasants were content to collect the naturally exuded gum, no pains being taken to make incisions, whereby alone white flaky gum is obtained. We have in fact heard an old druggist state, that he remembered the first appearance of this fine kind of tragacanth in the London market. According to Professor Haussknecht, whose observations relate chiefly to Kurdistan and Persia, the tragacanth collected in these regions is mostly a spontaneous exudation.
Tragacanth is brought to Smyrna, which is a principal market for it, from the interior, in bags containing about 2 quintals each, by native dealers who purchase it of the peasants. In this state it is a very crude article, consisting of all the gatherings mixed together. To fit it for the European markets, some of which have their special requirements, it has to be sorted into different qualities, as Flaky or Leaf Gum, Vermicelli and Common or Sorts; this sorting is performed almost exclusively by Spanish Jews.
[710] Hanbury, Science Papers, 29.
[711] Pharm. Journ. xv. (1856) 18.
[712] Researches in Asia Minor, Pontus and Armenia, i. (1842) 492.
=Description=—The peculiar conditions under which tragacanth exudes, arising from the pressure of the surrounding tissues and the power of solidifying a large amount of water, will account to some extent for the strange forms in which this exudation occurs.
The spontaneously exuded gum is mostly in mammiform or botryoidal masses from the size of a pea upwards, of a dull waxy lustre, and brownish or yellowish hue. It also occurs in vermiform pieces more or less contorted and very variable in thickness; some of them may have exuded as the result of artificial punctures. It is this form that bears the trade name of Vermicelli. The most valued sort is however the Flake Tragacanth, which consists of thin flattish pieces or flakes, 1, 2, 3 or more inches in length, by ¼ to 1 in width.[713] They are marked on the surface by wavy lines and bands, or by a series of concentric wave-marks, as if the soft gum had been forced out by successive efforts. The pieces are contorted and altogether very variable in form and size. The gum is valued in proportion to its purity and whiteness. The best, whether vermiform or flaky, is dull white, translucent, devoid of lustre, somewhat flexible and horny, firm, and not easily broken, inodorous and with scarcely any or only a slight bitterish taste.
The tragacanth of Kurdistan and Persia shipped from Bagdad, which sometimes appears in the London drug sales under the incorrect name of Syrian Tragacanth, is in very fine and large pieces which are rather more translucent and ribbon-like than the selected tragacanth imported from Smyrna: in fact, the two varieties when seen in bulk are easily distinguishable.
The inferior kinds of tragacanth have more or less of colour, and are contaminated with bark, earth and other foreign substances. They used formerly to be much imported into Europe, and were frequently mentioned during the past centuries as black tragacanth.
=Microscopic Structure=—The transformation of the cells into tragacanth is usually not so complete, that every trace of the original tissue or its contents has disappeared. In the ordinary drug, the remains of cell-walls as well as starch granules may be seen, especially if thin slices are examined under oil or any other liquid not acting on the gum. Polarized light will then distinctly show the starch and the cell-walls. If a thin section is imbued with a solution of iodine in iodide of potassium and then moistened with concentrated sulphuric acid, the cell-walls will assume a blue colour as well as the starch.
[713] In the Museum of the Pharmaceutical Society in London, there is some Flake Tragacanth remarkable for its enormous size, but in other respects precisely like the ordinary kind. The ribbon-like strips are as much as 2 inches wide and ³/₁₀ of an inch thick, and the largest which is several inches long weighs 2¾ ounces. Professor Haussknecht has informed us that he has seen in Luristan stems of Astragalus eriostylus Boiss. et Haussk. more than 6 feet in height and 5 inches in diameter, and bearing tragacanth. It is probable that the specimen of gum we have described was produced by some species attaining these extraordinary dimensions. Among the Kurdistan tragacanth, there occur curious cylindrical vermiform pieces, about ⅕ of an inch in diameter, coated with a network of woody fibre. We are told by Professor H. that they are picked out of the centre of cut off pieces of stem, split open by rapid drying in the sun.
=Chemical Composition=—When tragacanth is immersed in water it swells, and in the course of some hours disintegrates so that it can be diffused through the liquid. So great is its power of absorbing water that even with 50 times its weight, it forms a thick mucilage. If one part of tragacanth is shaken with 100 parts of water and the liquid filtered, a neutral solution may be obtained which yields an abundant precipitate with acetate of lead, and mixes clearly with a concentrated solution of ferric chloride or of borax,—in these respects differing from a solution of gum arabic. On the other hand, it agrees with the latter in that it is thrown down as a transparent jelly by alcohol, and rendered turbid by oxalate of ammonium. The residue on the filter is a slightly turbid, slimy, non-adhesive mucilage, which when dried forms a very coherent mass. It has received the name of Bassorin, Traganthin or Adraganthin, and agrees with the formula C₁₂H₂₀O₁₀.
Tragacanth is readily soluble in alkaline liquids, even in ammonia water and at the same time assumes a yellow colour; heated with ammonia in a sealed tube at 90° C. it blackens.
The drug loses by drying about 14 per cent. of water, which it absorbs again on exposure to the air. Pure flake tragacanth incinerated leaves 3 per cent. of ash.
=Commerce=—Tragacanth is shipped from Constantinople, Smyrna and the Persian Gulf. The annual export of the gum from Smyrna has been recently stated[714] to be 4,500 quintals, value 675,000 Austrian florins (£67,500); and the demand to be always increasing.
=Uses=—Though tragacanth is devoid of active properties, it is a very useful addition to many medicines. Diffused in water it acts as a demulcent, and is also convenient for the suspension of a heavy powder in a mixture. It is an important ingredient for imparting firmness to lozenges and pill-masses.
=Adulteration=—The fine quantities consisting of large distinct pieces are not liable to adulteration, but the small and the inferior kinds are often sophisticated. At Smyrna, tragacanth is mixed with gums termed respectively Mosul and Caramania Gum. The former appears to be simply very inferior tragacanth; the latter which is sometimes called in the London market Hog Gum Tragacanth or Bassora Gum,[715] is said to be the exudation of almond and plum trees. It occurs in nodular masses of a waxy lustre and dull brown hue, which immersed in water gradually swells into a voluminous white mass. To render this gum available for adulteration, the lumps are broken into small angular fragments, the size of which is adjusted to the sort of tragacanth with which they are to be mixed. As the Caramania Gum is somewhat dark, it is usual to whiten it by white lead, previous to mixing it with Small Leaf or Flake, or with the Vermicelli gum.
By careful examination the fraud is easily detected, angular fragments not being proper to any true tragacanth. The presence of lead may be readily proved by shaking suspected fragments for a moment with dilute nitric acid, which will dissolve any carbonate present, and afford a solution which may be tested by the ordinary reagents.
[714] C. von Scherzer, Smyrna, Wien, 1873. 143.
[715] It is sometimes shipped from Bussorah.
RADIX GLYCYRRHIZÆ
Radix Liquiritiæ; Liquorice Root; F. Réglisse; G. Süssholz, Lakritzwurzel.
=Botanical Origin=—Glycyrrhiza glabra L., a plant which under several well marked varieties[716] is found over an immense extent of the warmer regions of Europe, spreading thence eastward into Central Asia. The root used in medicine is derived from two principal Varieties, namely:—
α. typica—Nearly glabrous, leaves glutinous beneath, divisions of the calyx linear-lanceolate often a little longer than the tube, corolla purplish blue, legume glabrous, 3-6 seeded. It is indigenous to Portugal, Spain, Southern Italy, Sicily, Greece, Crimea, the Caucasian Provinces and Northern Persia; and is cultivated in England, France and Germany.
γ. glandulifera (G. glandulifera W.K.)—Stems more or less pubescent or roughly glandular, leaves often glandular beneath, legume sparsely or densely echinate-glandular, many-seeded, or short and 2-3 seeded. It occurs in Hungary, Galicia, Central and Southern Russia, Crimea, Asia Minor, Armenia, Siberia, Persia, Turkestan and Afghanistan.
G. glabra L. has long, stout, perennial roots, and erect, herbaceous annual stems. In var. α., the plant throws out long stolons which run horizontally at some distance below the surface of the ground.
=History=—Theophrastus[717] in commenting on the taste of different roots (3rd cent. B.C.) instances the sweet Scythian root which grows in the neighbourhood of the lake Mæotis (Sea of Azov), and is good for asthma, dry cough and all pectoral diseases,—an allusion unquestionably to liquorice. Dioscorides,[718] who calls the plant γλυκιῤρίζη, notices its glutinous leaves and purplish flowers, but as he describes the pods to be in balls resembling those of the plane, and the roots to be sub-austere (ὑπόστρυϕνοι) as well as sweet, it is possible he had in view Glycyrrhiza echinata L. as well as G. glabra.
Roman writers, as Celsus and Scribonius Largus, mention liquorice as Radix dulcis. Pliny, who describes it as a native of Cilicia and Pontus, makes no allusion to it growing in Italy.
The cultivation of liquorice in Europe does not date from a very remote period, as we conclude from the absence of the name in early mediæval lists of plants. It is, for instance, not enumerated among the plants which Charlemagne ordered (A.D. 812) to be introduced from Italy into Central Europe;[719] nor among the herbs of the convent gardens as described by Walafridus Strabus,[720] abbot of Reichenau, lake of Constance, in the 9th century; nor yet in the copious list of herbs contained in the vocabulary of Alfric, archbishop of Canterbury in the 10th century.[721]
[716] We accept those adopted by Boissier in his Flora Orientalis, ii. (1872) 202.
[717] Hist. Plant. lib. ix. c. 13.
[718] Lib. iii. c. 5.
[719] Pertz, Monumenta Germaniæ historica, Legum, i. (1835) 186.
[720] Migne, Patrologiæ Cursus, cxiv. 1122.
[721] Wright, Volume of Vocabularies, 1857. 30. This work contains several other early lists of plants.
On the other hand, liquorice is described as being cultivated in Italy by Piero de’ Crescenzi[722] of Bologna, who lived in the 13th century. The cultivation of the plant in the north of England existed at the close of the 16th century, but how much earlier we have not been able to trace.
As a medicine the drug was well known in Germany in the 11th century, and an extensive cultivation of the plant was carried on near Bamberg, Bavaria, in the 16th century, so that in many of the numerous pharmaceutical tariffs of those times in Germany not only Glycyrrhizæ succus creticus, seu candiacus, seu venetus is quoted, but also expressly that of Bamberg.[723]
The word Liquiritia, whence is derived the English name Liquorice (Lycorys in the 13th century), is a corruption of Glycyrrhiza, as shown in the transitional mediæval form Gliquiricia. The Italian Regolizia, the German Lacrisse or Lakriz, the Welsh Lacris[724] and the French Réglisse (anciently Requelice or Recolice) have the same origin.
=Cultivation, and habit of growth=—The liquorice plant is cultivated in England at Mitcham and in Yorkshire, but not on a very extensive scale. The plants, which require a good deep soil, well enriched by manure, are set in rows, attain a height of 4 to 5 feet and produce flowers but not seeds. The root is dug up at the beginning of winter, when the plant is at least 3 or 4 years old. The latter has then a crown dividing into several aerial stems. Below the crown is a principal root about 6 inches in length, which divides into several (3 to 5) rather straight roots, running without much branching, though beset with slender wiry rootlets, to a depth of 3, 4 or more feet.[725] Besides these downward-running roots, the principal roots emit horizontal runners or stolons, which grow at some distance below the surface and attain a length of many feet. These runners are furnished with leaf buds and throw up stems in their second year.
Every portion of the subterraneous part of the plant is carefully saved; the roots proper are washed, trimmed, and assorted, and either sold fresh in their entire state, or cut into short lengths and dried, the cortical layer being sometimes first scraped off. The older runners distinguished at Mitcham as “hard,” are sorted out and sold separately; the young, called “soft,” are reserved for propagation.
In Calabria, the singular practice prevails of growing the liquorice among the wheat in the cornfields.
=Description=—Fresh liquorice (English) when washed is externally of a bright yellowish-brown. It is very flexible, easily cut with a knife, exhibiting a light yellow, juicy, internal substance which consists of a thick bark surrounding a woody column. Both bark and wood are extremely tough, readily tearing into long, fibrous strips. The root has a peculiar earthy odour, and a strong and characteristic sweet taste.
[722] Libro della Agricoltura, Venet. 1511. lib. vi. c. 62.
[723] Gesner, Valerii Cordi Hist. stirp. Argentorati, 1561. 164.—Flückiger, Documente zur Geschichte der Pharmacie, Halle, 1876. 39. 46.
[724] In the “Meddygon Myddvai” of the 13th century, Llandovery, 1861, p. 159. 355 (it is written there Licras).
[725] This form of root, which reminds one of a whip with three or four lashes and a very short handle, is probably due to the method of propagating adopted at Mitcham, where a short stick or runner is planted upright in the ground.
Dried liquorice root is supplied in commerce either with or without the thin brown coat In the latter state it is known as peeled or decorticated. The English root, of which the supply is very limited, is usually offered cut into pieces 3 or 4 inches long, and of the thickness of the little finger.
Spanish Liquorice Root, also known as Tortosa or Alicante Liquorice, is imported in bundles several feet in length, consisting of straight unpeeled roots and runners, varying in thickness from ¼ to 1 inch. The root is tolerably smooth or somewhat transversely cracked and longitudinally wrinkled; that from Tortosa is usually of a good external appearance, that from Alicante sometimes untrimmed, dirty, of very unequal size, showing frequently the knobby crowns of the root. Alicante liquorice root is sometimes shipped in bags or loose.
Russian Liquorice Root, which is much used in England, is we presume derived from G. glabra var. glandulifera. It is imported from Hamburg in large bales, and is met with both peeled and unpeeled. The pieces are 12 to 18 inches long, with a diameter of ¼ of an inch to 1 or even 2 inches. Sometimes very old roots, split down the centre and forming channelled pieces as much as 3½ inches wide at the crown end, are to be met with. This liquorice in addition to being sweet has a certain amount of bitterness.
=Microscopic Structure=—The root exhibits well-marked structural peculiarities. The corky layer is made up of the usual tabular cells; the primary cortical tissue of a few rows of cells. The chief portion of the bark consists of liber or endophlœum, and is built up for the most part of parenchymatous tissue accompanied by elongated fibres of two kinds, partly united into true liber-bundles and partly forming a kind of network, the smaller threads of which deviate considerably from the straight line. Solution of iodine imparts an orange hue to both kinds of bast-bundles, and well displays the structural features of the bark.
The woody column of the root exhibits three distinct forms of cell, namely ligneous cells (libriform) with oblique ends; parenchymatous, almost cubic cells; and large pitted vessels. In the Russian root, the size of all the cells is much more considerable than in the Spanish.
=Chemical Composition=—The root of liquorice contains, in addition to sugar and albuminous matter, a peculiar sweet substance named Glycyrrhizin, which is precipitated from a strong decoction upon addition of an acid or solution of cream of tartar, or neutral or basic acetate of lead. When washed with dilute alcohol and dried, it is an amorphous yellow powder, having a strong bitter-sweet taste and an acid reaction. It forms with hot water a solution which gelatinizes on cooling, does not reduce alkaline tartrate of copper, is not fermentable, and does not rotate the plane of polarization. From the analysis and experiments of Rösch, performed in the laboratory of Gorup-Besanez at Erlangen, in 1876, the formula C₁₆H₂₄O₆ was derived for glycyrrhizin. By boiling it with dilute hydrochloric or sulphuric acid it is resolved into a resinous amorphous bitter substance named Glycyrretin, and an uncrystallizable sugar having the characters of glucose. The formula of glycyrretin has not yet been settled. Weselsky and Benedikt, in 1876, showed that 65 per cent. of it may be obtained from glycyrrhizin. By melting glycyrretin with about 5 parts of caustic potash paraoxy-benzoïc acid is produced.
Alkalis easily dissolve glycyrrhizin with a brown colour and emission of a peculiar odour. In the root it perhaps exists combined with ammonia, inasmuch as the aqueous extract evolves that alkali when warmed with potash (Roussin, 1875). According to Sestini (1878) glycyrrhizin is present in the root combined with calcium; he obtained 6·3 per cent. of glycyrrhizin from the root previously dried at 110°. By exhausting glycyrrhizin with glacial acetic acid Habermann in 1876 succeeded in isolating almost colourless crystals having the sweet taste of the root. They yield, by boiling them with dilute acids, a yellow substance which would appear to agree with glycyrretin. The deep yellow walls of the vessels and prosenchymatous cells appear to be the chief seat of the glycyrrhizin.
The sugar of liquorice root has not yet been isolated; the aqueous infusion of the dried root separates protoxide of copper from an alkaline solution of cupric tartrate. Yet the sugar as extracted from the fresh root by cold water does not precipitate alkaline cupric tartrate at all in the cold, and not abundantly even on prolonged boiling.
Asparagin was obtained from the root by Robiquet (1809) and by Plisson (1827). Sestini (1878) isolated 2-4 parts of asparagin from 100 parts of the root dried at 110° C. Robiquet also found the root to contain malic acid. The presence of starch in abundance is shown by the microscope as well as by testing a decoction of the root with iodine. The outer bark of the root contains a small quantity of tannin.
=Commerce=—Liquorice root is imported into Great Britain from Germany, Russia and Spain, but there are no data for showing to what extent. France imported in 1872 no less than 4,348,789 kilogrammes (4282 tons), which was more than double the quantity imported the previous year.[726]
Liquorice root is much used in China, and is largely produced in some of the northern provinces. In 1870, 1,304 peculs were shipped from Ningpo,[727] and 7,147 pepuls in 1877 from Cheefu (one pecul = 133·33 lb. avdp.).
=Uses=—Liquorice root is employed for making extract of liquorice and in some other pharmaceutical preparations. The powdered root is used to impart stiffness to pill-masses and to prevent the adhesion of pills. Liquorice has a remarkable power of covering the flavour of nauseous medicines. As a domestic medicine, liquorice root is far more largely used on the Continent than in Great Britain.
[726] Documents statistiques réunis par l’administration des Douanes sur le commerce de la France, année 1872, Paris, 1873.
[727] Reports on Trade at the Treaty Ports in China for 1870, Shanghai, 1871. 13. 62.
SUCCUS GLYCYRRHIZÆ
Succus Liquiritiæ, _Extractum Glycyrrhizæ Italicum_; Italian Extract of Liquorice, Spanish Liquorice, Spanish Juice; F. Jus ou Suc de Réglisse; G. Süssholzsaft, Lakriz.
=Botanical Origin=—Glycyrrhiza glabra L., see preceding article, p. 179.
=History=—Inspissated liquorice juice was known in the time of Dioscorides, and may be traced in the writings of Oribasius and Marcellus Empiricus in the latter half of the 4th century, and in those of Paulus Ægineta in the 7th. It appears to have been in common use in Europe during the middle ages. In A.D. 1264, “Liquorice” is charged in the Wardrobe Accounts of Henry III.;[728] and as the article cost 3_d_. per lb., or the same price as grains of paradise and one-third that of cinnamon, we are warranted in supposing the extract and not the mere root is intended. Again, in the Patent of Pontage granted by Edward I., A.D. 1305, to aid in repairing the London Bridge, permission is given to lay toll on various foreign commodities including Liquorice.[729] A political song written in 1436[730] makes mention of Liquorice as a production of Spain, but the plant is not named as an object of cultivation by Herrera, the author of a work on Spanish agriculture in 1513.
Saladinus,[731] who wrote about the middle of the 15th century, names it among the wares kept by the Italian apothecaries; and it is enumerated in a list of drugs of the city of Frankfort written about the year 1450.[732]
Dorsten,[733] in the first half of the 16th century, mentions the liquorice plant as abundant in many parts of Italy, and describes the method of making the Succus by crushing and boiling the fresh root. Mattioli[734] states that the juice made into pastilli was brought every year from Apulia, and especially from the neighbourhood of Monte Gargano. Extract of liquorice was made at Bamberg in Germany, where the plant is still largely cultivated, as early as 1560.[735]
=Manufacture=—This is conducted on a large scale in Spain, Southern France, Sicily, Calabria, Austria, Southern Russia (Astracan and Kasan), Greece (Patras) and Asia Minor (Sokia and Nazli, near Smyrna); but the extract with which England is supplied is almost exclusively the produce of Calabria, Sicily and Spain.
The process of manufacture varies only by reason of the amount of intelligence with which it is performed, and the greater or less perfection of the apparatus employed. As witnessed by one of us (H.) at Rossano in Calabria in May, 1872, it may be thus described from notes made at the time. The factory employs about 60 persons, male and female. The root having been taken from the ground the previous winter, is stacked in the yard around the factory; it is mostly of the thickness of the fingers, with here and there a piece of larger size up to a diameter of nearly 2 inches; some of it sprouting.
[728] Rogers, Hist. of Agriculture and Prices, ii. (1866) 543.
[729] Chronicles of London Bridge, 1827. 155.
[730] Wright, Political Poems and Songs (Master of the Rolls series), ii. (1861) 160.
[731] Compendium Aromatariorum, Bonon. 1488.
[732] Flückiger, Die Frankfurter Liste, Halle, 1873, page 10, No. 204.
[733] Botanicon, Francof. 1540. 175.
[734] Comm. in lib. Diosc., Basil. 1574. 485.
[735] Gesner, Horti Germanici, Argent. 1561. 257, b.
As required, the root is taken within the building and crushed under a heavy millstone to a pulp, water-power being employed. It is then transferred to boilers and boiled with water over a naked fire. The decoction is run off and the residual root pressed in circular bags like those used in the olive-mills. The liquor which is received into cisterns below the floor is then pumped up into copper pans, in which the evaporation is conducted also over the naked fire—even to the very last, care being taken by constant stirring to avoid burning the extract. The extract or pasta is removed from the pan while warm, and taken in small quantities to an adjoining apartment where a number of women are employed in rolling it into sticks. It is first weighed into portions, each of which the woman seated at the end of a long table tears with her hand into about a dozen pieces. These are passed to the women sitting next who roll them with their hands into cylindrical sticks, the table on which the rolling is done being of wood, and the pasta moistened with oil to prevent its adhesion to the hands. Near the further end of the table are some frames made of marble or metal, clean and bright, so arranged as to bring the sticks when rolled in them to the proper length and thickness. When thus adjusted, they are carefully ranged on a board, and a woman then stamps them with the name of the manufacturer. Lastly the sticks laid on boards are stacked up in a room to dry.
In some establishments the vacuum-pan has been introduced for the inspissation of the decoction. At the great manufactory of Mr. A. O. Clarke at Sokia near Smyrna, all the processes are performed by steam power.
=Description=—Liquorice juice of good quality is met with in cylindrical sticks stamped at one end with the maker’s name or mark. They are of various sizes, but generally not larger than 6 to 7 inches long by about an inch in diameter. They are black, when new or warm slightly flexible, but breaking when struck, and then displaying a sharp-edged fracture, and shining conchoidal surface on which a few air bubbles are perceptible; thin splinters are translucent. The extract has a special odour and dissolves in the mouth with a peculiar strong sweet taste. By complete drying, it loses from 11 to 17 per cent. of water.
Several varieties of Stick Liquorice are met with in English commerce, and command widely different prices. The most famous is the Solazzi Juice, manufactured at Corigliano, a small town of Calabria in the gulf of Taranto, at an establishment belonging to the sons of Don Onorato Gaetani, duke of Laurenzano and prince of Piedimonte d’Alife, who inherited the manufacture from his father-in-law, the Cavaliere Domenico Solazzi Castriota. The Solazzi Juice destined for the English market is usually shipped at Naples; it has for many years been wholly consigned to two firms in London, and in quantity not always equal to the demand. Of the other varieties we may mention Barracco, manufactured at the establishment of Messieurs Barracco at Cotrone on the eastern coast of Calabria; Corigliano, produced at a factory at Corigliano, belonging to Baron Compagna. The sticks stamped Pignatelli are from the works of Vincenzo Pignatelli, prince of Strongoli, at Torre Cerchiora, where 300 to 400 workmen are employed.
The juice is also imported in a block form, having while warm and soft been allowed to run into the wooden case in which it is exported. This juice, which is known as Liquorice Paste, is largely imported from Spain and Asia Minor, but on account of a certain bitterness is unsuited for use as a sweetmeat.
=Chemical Composition=—Hard extract of liquorice, such as that just described, is essentially different in composition and properties from the Extract of Liquorice (Extractum Glycyrrhizæ) of the British Pharmacopœia.[736] The latter is a soft, hygroscopic substance, entirely soluble in cold water, whereas the so-called Spanish Juice when treated with cold water leaves a large residue undissolved.
It has been sometimes supposed that the presence of this residue indicates adulteration, but such is far from being the fact, as was conclusively shown by the researches of a French Commission appointed to investigate the process recommended by Delondre.[737] This commission subjected liquorice root to the successive action of cold water, boiling water, and lastly of steam. By the first menstruum 15 per cent., and by the second an additional 7½ per cent., were obtained of a hygroscopic extract much more soluble than commercial liquorice, and totally unsuitable for being moulded into sticks. The residue having been then exhausted by steam, 16 per cent. was obtained of an extract differing entirely from those of the previous operations. It was a dry friable substance, cracking and falling to pieces in the drying stove, having a sweet taste without acridity, not readily dissolving in the mouth, and very imperfectly soluble in cold water. This then was the substance required to give firmness to the more soluble matter, and to render possible the preparation of an extract possessing that degree of solubility and hardness which would render it an agreeable sweetmeat, as well as a permanent and stable commodity. In fact, by treating the root at once with steam according to Delondre’s process, the experimenters obtained 42 to 45 per cent. of extract having all the qualities desired in good Italian or Spanish Juice.
When the latter substance is suspended in water undisturbed, the soluble matter may be dissolved out, the stick still retaining its original form. Glycyrrhizin, which is but slightly soluble in cold water, remains to some extent in the residue, and by an alkaline solution may be afterwards extracted together with colouring matter and probably also pectin. The proportion of soluble matter which the best varieties of liquorice juice yield to cold water varies from about 60 to 70 per cent. A sample of Solazzi Juice recently examined by one of us, lost 8·4 per cent. when dried at 100° C.; it was then exhausted by 60 times its weight of cold water used in successive quantities, by which means 66·8 per cent. of soluble matter were removed. The residue consisted of minute starch granules, fragments of the root, and colouring matter partially soluble in ammonia. Small shreds of copper were also visible to the naked eye. The dried juice yielded 6·3 per cent. of ash.
[736] Made by treating the crushed root with cold water.
[737] Journ. de Pharm. xxx. (1856) 428; an abstract by Redwood in Pharm. Journ. xvi. (1857) 403.
Corigliano liquorice treated in the same manner gave 71·2 per cent. of extract soluble in cold water; Barracco liquorice 64·9.
The small liquorice lozenges known as Pontefract Cakes (Dunhill’s), not previously dried, gave 71 per cent. of matter soluble in cold water.
=Commerce=—The value of the imports of Liquorice into the United Kingdom has been for the last five years as follows:—
1868 1869 1870 1871 1872 £89,482 £83,832 £70,165 £55,129 £75,991
The last named sum represents a quantity of 28,000 cwt., of which 11,170 cwt. were furnished by Italy, and the remainder by Turkey, France, Spain and other countries.
The total exports of Liquorice Paste from Smyrna were estimated in 1872 as 1,200 to 1,400 tons (24,000 to 28,000 cwt.) per annum.
=Uses=—Stick liquorice is sucked as a remedy for coughs, and by children as a sweetmeat. It is also used in lozenges, and in some pharmacopœias is admitted as the raw material from which to prepare soft extract of liquorice.
The block liquorice, of which a large quantity is imported, is chiefly used in the manufacture of tobacco for smoking and chewing.
OLEUM ARACHIS
Ground-nut oil, Earth-nut oil, Pea-nut oil, Arachis oil; F. Huile d’Arachide ou de Pistache de terre; G. Erdnussöl.
=Botanical Origin=—Arachis hypogæa L., a diffuse herbaceous annual plant, having stems a foot or two long, and solitary axillary flowers with an extremely long filiform calyx-tube. After the flower withers, the torus supporting the ovary becomes elongated as a rigid stalk, which bends down to the ground and forces into it the young pod, which matures its seeds some inches below the surface. The ripe pod is oblong, cylindrical, about an inch in length, indehiscent, reticulated, and contains one or two, or exceptionally even four irregularly ovoid seeds.
The plant is cultivated for the sake of its nutritious oily seeds in all tropical and subtropical countries, but especially on the west coast of Africa. It is unknown in the wild state. De Candolle[738] regards it as a native of Brazil, to which region the other species of the genus exclusively belong. But the opinion of one of us[739] is strongly in favour of the plant being indigenous to Tropical Africa, and so is that also of Schweinfurth. Arachis is one of the most universally cultivated plants throughout Tropical Africa, from Senegambia to lake Tanganyika. In Europe it has not proved remunerative.
[738] Géographie Botanique, ii. (1855) 963.
[739] Flückiger, Ueber die Erdnuss—Archiv der Pharmacie, 190. (1869) 70-84, with figure.
=History=—The first writer to notice Ground-Nut appears to be Fernandez de Oviedo y Valdes, who lived in Hayti from A.D. 1513 to 1525; he mentions in his Cronica de las Indias[740] that the Indians cultivated very much the fruit Mani, a name still used for Arachis in Cuba and in South America. A little later, Monardes,[741] described a nameless subterraneous fruit, found about the river Maranon and held in great esteem by both Indians and Spaniards. But before, the French colonists sent in 1555 by Admiral Coligny to the Brazilian coast had become acquainted with the “Mandobi,” which Jean de Léry[742] described quite unmistakably. Good accounts and figures of it were given in the following century by Johannes de Laet (1625),[743] and by Marcgraf,[744] who calls it by its Brazilian name of Mundubi. It is enumerated by Stisser among the rare plants cultivated by him at Helmstedt (Brunswick), about the year 1697.[745]
It is only in very recent times that the value of the Ground-Nut has been recognized in Europe. Jaubert, a French colonist at Gorée near Cape Verde, first suggested about 1840 its importation as an oil-seed into Marseilles, where it now constitutes one of the most important articles of trade.[746]
=Description=—The fat oil of Arachis, as obtained by pressure without heat, is almost colourless, of an agreeable faint odour and a bland taste resembling that of olive oil. An inferior oil is obtained by warming the seeds before pressing them. The best oil has a sp. gr. of about 0·918; it becomes turbid at 3° C., concretes at -3° to -4°, and hardens at -7°. On exposure to air it is but slowly altered, being one of the non-drying oils. At length it thickens considerably, and assumes even in closed vessels a disagreeable rancid smell and taste.
=Chemical Composition=—The oil consists of the glycerides of four different fatty acids. The common Oleic Acid, C₁₈H₃₄O₂, that is to say its glycerin compound, is the chief constituent of Arachis oil. Hypogæic Acid, C₁₆H₃₀O₂, has been pointed out by Gössmann and Scheven (1854) as a new acid, whereas it is thought by other chemists to agree with one of the fatty acids obtained from whale oil. The melting point of this acid from Arachis oil is 34-35° C. The third acid afforded by the oil is ordinary Palmitic Acid, C₁₆H₃₂O₂, with a fusing point of 62° C. Arachic Acid, C₂₀H₄₀O₂, the fourth constituent, has also been met with among the fatty acids of butter and olive oil, and, according to Oudemans (1866), in the tallow of Nephelium lappaceum L., an Indian plant of the order Sapindaceæ.
When ground-nut oil is treated with hyponitric acid, which may be most conveniently evolved by heating nitric acid with a little starch, a solid mass is obtained, which yields by crystallization from alcohol Elaïdic and Gæidinic acids, the former isomeric with oleic, the latter with hypogæic acid.
=Production and Commerce=—The pods are exported on an immense and ever increasing scale from the West Coast of Africa. From this region, not less than 66 millions of kilogrammes, value 26 millions of francs (£1,040,000), were imported in 1867, almost exclusively into Marseilles. From the French possessions on the Senegal, 24 millions of kilogr. were exported in 1876.
[740] Lib. vii. cap. 5. Fol. 1074 f. (1547), as quoted by C. Ph. von Martius in Gelehrte Anzeigen der bayerischen Akademie, 1839. 969.
[741] Las Cosas que se traen de nuestras Indias Occidentales, Sevilla, 1569, part 2.
[742] Histoire d’un voyage faict en la Terre du Bresil, autrement dite Amérique, 1586. 204 (first edition La Rochelle, 1578).
[743] Histoire du Nouveau Monde, Leyde, 1640. 503.
[744] Hist. Rerum Nat. Brasil. 1648. 37.
[745] Botanica curiosa, Helmst. 1697. 38.
[746] Duval, Colonies et politique coloniale de la France, 1864. 101.—Mavidal, Le Sénégal, son état présent, son avenir, Paris, 1863. 171.—Carrère et Holle, La Sénégambie Française, 1855. 84.—Poiteau, in Annales des Sciences nat., Botanique, xix. (1853) 268.
The oil is exported from India where the ground-nut is also cultivated, though not on so large a scale as in Western Africa. In Europe it is manufactured chiefly at Marseilles, London, Hamburg and Berlin. The yield of the seeds varies from 42 to nearly 50 per cent. The softness of the seeds greatly facilitates their exhaustion, whether by mechanical power or by the action of bisulphide of carbon or other solvent.
=Uses=—Good arachis oil may be employed in pharmacy in the same way as olive oil, for which it is a valuable substitute, though more prone to rancidity. It has been introduced into the Pharmacopœia of India, and is generally used instead of olive oil in the Indian Government establishments. Its largest application is for industrial purposes, especially in soap-making.
RADIX ABRI
Indian Liquorice; F. Liane à réglisse, Réglisse d’Amérique.
=Botanical Origin=—Abrus precatorius L., a twining woody shrub[747] indigenous to India, but now found in all tropical countries.
=History=—The plant is mentioned in the Sanskrit medical writings of Susruta, whence we may infer that it has long been employed in India. Its resemblance to liquorice was remarked by Sloane (1700), who called it Phaseolus glycyrrhites. As a substitute for liquorice, the root has been often employed by residents in the tropical countries of both hemispheres. It was introduced into the Bengal Pharmacopœia of 1844, and into the Pharmacopœia of India of 1868.
The seeds, of the size of a small pea, well known for their polish and beautiful black and red colours, have given their name of Retti to a weight (= 2³/₁₆ grains) used by Hindu jewellers and druggists.
=Description=—The root is long, woody, tortuous and branching. The stoutest piece in our possession is as thick as a man’s finger, but most of it is much more slender. The cortical layer is extremely thin and of a light brown or almost reddish hue. The woody part breaks with a short fibrous fracture exhibiting a light yellow interior. The root has a peculiar, disagreeable odour, and a bitterish acrid flavour leaving a faintly sweet after-taste. When cut into short lengths it has a slight resemblance to liquorice, but may easily be distinguished by means of the microscope.
Mr. Moodeen Sheriff,[748] who says he has often examined the root of Abrus both fresh and dried, remarks that it is far from abounding in sugar as generally considered;—that it does not possess any sweetness at all until it attains a certain size, and that even then its sweet taste is not always well marked. As it is often mixed in the Indian bazaars with true liquorice, he thinks the latter may have sometimes been mistaken for it.
[747] Fig. in Bentley and Trimen, Medicinal Plants, part 25 (1878).
[748] Supplement to the Pharmacopœia of India, Madras, 1869. 16.—The author has kindly sent us specimens of the root. We are also indebted for authentic samples to Mr. Thwaites of the Royal Botanical Garden, Ceylon, and to Mr. Prestoe of the Botanical Garden, Trinidad. The last named gentleman remarks—“I do not find any liquorice property in the root, even fresh, but it is very strong in the green leaves.”
=Microscopic Structure=—On a transverse section the bark exhibits some layers of cork-cells, loaded with brown colouring matter, and then, within the middle zone of the bark, a comparatively thick layer of sclerenchymatous tissue. Strong liber-fibres are scattered through the interior of the cortical tissue, but are not distributed so as to form wedge-shaped rays as met with in liquorice. In the latter the sclerenchyme (thick-walled cells) is wanting. These differences are sufficient to distinguish the two roots.
=Chemical Composition=—The concentrated aqueous infusion of the root of Abrus has a dark brown colour and a somewhat acrid taste accompanied by a faint sweetness. When it is mixed with an alkaline solution of tartrate of copper, red cuprous oxide is deposited after a short time: hence we may infer that the root contains sugar. One drop of hydrochloric or other mineral acid mixed with the infusion produces a very abundant flocculent precipitate, which is soluble in alcohol. If the infusion of Abrus root is mixed with a very little acetic acid, an abundant precipitate is likewise obtained, but is dissolved by an excess. This behaviour is similar to that of glycyrrhizin (see p. 181).
Berzelius observed, so long ago as 1827, that the leaves of Abrus contain a sweet principle similar to that of liquorice.
=Uses=—The root has been used in the place of liquorice, for which it is in our opinion a very bad substitute.
SETÆ MUCUNÆ
Dolichi pubes vel setæ; Cowhage, Cow-itch[749]; F. Pois à gratter, Pois pouillieux; G. Juckborsten.
=Botanical Origin=—Mucuna pruriens DC. (Dolichos pruriens L., Stizolobium pruriens Pers., Mucuna prurita Hook.), a lofty climbing plant[750] with large, dark purple papilionaceous flowers, and downy legumes in size and shape not unlike those of a sweet pea, common throughout the tropical regions of both Africa, India and America.
=History=—The earliest notice we have found of this plant is that of Parkinson, who in his Theater of Plants, published in 1640, names it “Phaseolus siliquâ hirsutâ, the Hairy Kidney-Beane called in Zurrate [Surat] where it groweth, Couhage” It was subsequently described by Ray (1686), who saw the plant raised from West Indian seeds, in the garden of the Hatton family in Holborn.[751] Rheede figured it in the Hortus Malabaricus,[752] and it was also known to Rumphius and the other older botanists. We find it even in the pharmaceutical tariff of the county of Nürnberg, A.D. 1714.[753]
[749] These names and the following are also applied to the entire pods, or even to the plant.
[750] Fig. in Bentley and Trimen, Med. Plants, part 13 (1876).
[751] Hist. Plant. i. 887.
[752] Tom. viii. (1700) tab. 35, sub nom. Nāi Corana.
[753] Flückiger, Documente zur Geschichte der Pharmacie, Halle, 1876. 84.
The employment of cowhage as a vermifuge originated in the West Indies, and is quite unknown in the East. In England the drug began to attract attention in the latter part of the last century, when it was strongly recommended by Bancroft in his Natural History of Guiana (1769), and by Chamberlaine, a surgeon of London, who published an essay[754] descriptive of its effects which went through many editions. It was introduced into the Edinburgh Pharmacopœia of 1783, and into the London Pharmacopœia of 1809. At the present day it has been almost discarded from European medicine, but has been allowed a place in the Pharmacopœia of India (1868).
The name Cowhage is Hindustani, and in the modern way is written Kiwânch, which is generally derived from the Sanskrit Kapi-Kachchu, monkey’s itch (Dr. Rice); the corruption into Cow-itch is absurd. Mucuna is the Brazilian name of another species mentioned in 1648 by Marcgraf.[755]
=Description=—The pods are 2 to 4 inches long, about ⁴/₁₀ of an inch wide, and contain 4 to 6 seeds; they are slightly compressed and of a dark blackish brown. Each valve is furnished with a prominent ridge running from the apex nearly to the base, and is densely covered with rigid, pointed, brown hairs, measuring about ⅒ of an inch in length. The hairs are perfectly straight and easily detached from the valves, out of the epidermis of which they rise. If incautiously touched, they enter the skin and occasion an intolerable itching.
=Microscopic Structure=—Under the microscope the hairs are seen to consist of a single, sharply pointed, conical cell, about ¹/₄₀ of an inch in diameter at the base, with uniform brownish walls 5 mkm. thick, which towards the apex are slightly barbed. Occasionally a hair shows one or two transverse walls. Most of the hairs contain only air; others show a little granular matter which acquires a greenish hue on addition of alcoholic solution of perchloride of iron. If moistened with chromic acid, no structural peculiarity is revealed that calls for remark. The walls however are somewhat separated into indistinct layers, the presence of which is confirmed by the refractive power displayed by the hairs in polarized light.
=Chemical Composition=—The hairs when treated with sulphuric acid and iodine assume a dark brown colour. Boiling solution of potash does not considerably swell or alter them. They are completely decolorized by concentrated nitric acid.
=Uses=—Cowhage is administered for the expulsion of intestinal worms, especially Ascaris lumbricoides and A. vermicularis, which it effects by reason of its mechanical structure. It is given mixed with syrup or honey in the form of an electuary.
The root and seeds are reputed medicinal by the natives of some part of India. The pods when young and tender may be cooked and eaten.
[754] On the efficacy of Stizolobium or Cowhage, Lond. 2nd ed. 1784.
[755] Hist. Nat. Brasil. 18.
SEMEN PHYSOSTIGMATIS
Faba Calabarica, Faba Physostigmatis; Calabar Bean, Ordeal Bean of Old Calabar, Eseré Nut, Chop-nut; F. Fève de Calabar; G. Calabarbohne.
=Botanical Origin=—Physostigma venenosum Balfour, a perennial plant resembling the common Scarlet Runner (Phaseolus multiflorus Lam.) of our gardens, but having a woody stem often an inch or two thick, climbing to a height of 50 feet or more. It grows near the mouths of the Niger and the Old Calabar River in the Gulf of Guinea.
The imported seeds germinate freely, but the plant, though it thrives vigorously in a hothouse, has not yet, we believe, flowered in Europe. It has already been introduced into India and Brazil. In the latter country Dr. Peckolt, late of Cantagallo, has raised plants which have blossomed abundantly, producing racemes of about 30 flowers each, pendent from the axils of the ternate leaves.
The flower, which is fully an inch across and of a purplish colour, has the form of Phaseolus, but is distinguished from that genus by two special characters, namely that it has the style developed beyond the stigma backwards as a broad, flat, hooked appendage,[756] and the seeds half surrounded by a deeply grooved hilum.
=History=—The pagan tribes of Tropical Western Africa compel persons accused of witchcraft to undergo the ordeal of swallowing some vegetable poison. One of the substances employed in this horrid custom is the seed under notice, which is administered in substance or in the form of emulsion, or even as a clyster. It was first made known in England by Dr. W. F. Daniell about the year 1840, and subsequently alluded to in a paper read by him before the Ethnological Society in 1846.[757] The highly poisonous effects of the bean were observed in 1855 by Christison[758] in his own person, and in 1858 by Sharpey, who administered it to frogs.
Before the seed became an object of commerce, it was regarded by the natives with some mystery and was reluctantly parted with to Europeans. It was moreover customary in Old Calabar to destroy the plant whenever found, a few only being reserved to supply seeds for judicial purposes, and of these seeds the store was kept in the custody of the native chief. In 1859, the Rev. W. C. Thomson, a missionary on the West Coast of Africa, forwarded the plant to Professor Balfour of Edinburgh, who figured and described it as a type of a new genus.[759]
[756] The name of the genus, from ϕύσα, a bladder, was formed under the notion that this appendage is hollow, which is not the fact.—Mucuna cylindrosperma Welwitsch, from Angola, is probably the same plant. See Holmes, Pharm. J. ix. (1879) 913.
[757] Edinb. New Phil. J. xl. (1846) 313.
[758] Edinb. Journ. of Medical Science, xx. (1855) 193; Pharm. Journ. xiv. (1855) 470.
[759] Trans. Roy. Soc. of Edinb. xxii. (1861) 305. t. 16-17; see also Baillon, Hist. des Plantes, ii. 206. figg. 153-155, and Bentley and Trimen, Med. Plants, part 6 (1876).
Fraser of Edinburgh (about 1863 or earlier) discovered the specific power of the seed in contracting the pupil, when the alcoholic extract is applied to the eye. These myotic effects, counteracting those of atropine and hyoscyamine, were further examined by many other experimenters on mammals or birds. The action of the poison when taken internally was found rapidly to affect the cardiac contractions and finally to paralyze the heart.
=Description=—The fruit of Physostigma is a dehiscent, oblong legume about 7 inches in length, containing 2 or 3 seeds. The latter, commonly known as Calabar Beans, are 1 to 1⅜ inches long, about ⁶/₈ of an inch broad, and ⁴/₈ to ⅝ of an inch in thickness, weighing on an average twenty seeds, 67 grains each.
They have an oblong, subreniform outline, one side being straight or but slightly incurved, the other boldly arched. The latter is marked by a broad furrow, ⅛ of an inch wide, bordered with raised edges, and running from the micropyle, which is a small funnel-shaped depression, quite round the opposite end of the seed. In the middle of this remarkable furrow the raphe is seen as a long raised suture running from end to end. The surface of the seed is somewhat rough, but has a dull polish; it is of a deep chocolate-brown, passing into a lighter tint on the ridges bordering the furrow. The latter is black, dull, and finely rugose.
When the seed is broken the cotyledons are found adherent to the testa, with a large cavity between them. The air thus included causes the seeds to float on water, but they sink immediately when broken. After digestion for some hours in warm water, the testa having been previously cracked, the whole seed softens and swells so that its structure may be easily studied. Each cotyledon is then seen to be marked on the hilum-side by a long shallow furrow, at one end of which, just below the micropyle, lies the plumule and radicle. A dark brown inner membrane, constituting part of the testa, surrounds the cotyledons.
The seeds have scarcely any taste, or not more than an ordinary bean; nor in the dry state have they any odour. After being boiled, or when their alcoholic tincture is evaporated, an odour suggesting cantharides is developed.
=Microscopic Structure=—The cotyledons are built up of large globular or ovoid cells, those of the outermost layer being smaller and of rather cubic form. This parenchyme is loaded with starch granules, frequently as much as 50 mkm. in diameter. Their interior part is less distinctly stratified than the outer; the hollow centre radiates in various directions around the axis of the ovate granule. Polarized light does not show a cross as in other more globular starch granules, but two elliptic curves approaching one another near the axis of the granule. Similar starch granules are commonly met with in the seeds of Leguminosæ.
In the Calabar seeds the starch is accompanied by numerous particles of albuminous matter becoming distinctly perceptible by addition of iodine, which imparts to them an orange colouration.
The shell of the seed is built up of four different layers; the prevailing layer consists of very long, simply cylindrical cells, densely packed so as to form only one radial row. Tison[760] has endeavoured to ascertain in what region of the seed the active principle is lodged; and he has arrived at the conclusion that its seat is the granular protoplasmic particles, which alone acquire an orange tint by the action of weak caustic alkalis.
[760] Histoire de la Fève de Calabar, Paris, 1873. 38.
=Chemical Composition=—Jobst and Hesse[761] proved in 1863 that the poisonous nature of Calabar bean depends upon an alkaloid, to which they gave the name Physostigmine. It is obtained by the method generally adopted for extracting analogous substances, that is, by precipitating one of its salts from an aqueous solution by bicarbonate of sodium, and dissolving out the base with ether or benzol. As extracted by these chemists, physostigmine is an amorphous mass of decidedly alkaline reaction, soluble in much water and in acids. On exposure to the air the solution soon becomes red, or sometimes intensely blue, a partial decomposition of the alkaloid taking place. The red coloration may even be observed in the aqueous infusion of a few cotyledons. It disappears by sulphuretted hydrogen or sulphurous acid, but returns if these reducing agents are allowed to evaporate.
Hesse[762] ascertained (1867) that physostigmine consists of C₃₀H₂₁N₃O₄; he now obtained it perfectly colourless and tasteless, softening at 40° C., fusing at 45°, but not supporting a heat of 100° C., without decomposition, which is manifested by a red coloration.
In 1865 Vée and Leven,[763] by treating the powdered unpeeled seed in nearly the same way, prepared an alkaloid which they called Eserine. It differs from Hesse’s physostigmine in that it forms colourless, rhomboidal, tabular crystals of a bitter taste, melting at 90° C. It dissolves easily in ether, alcohol, or chloroform, but very sparingly in water. The last named solution is alkaline, and reddens by exposure to the air.
It is assumed by some writers, as Tison,[764] that eserine is only the pure form of physostigmine; but at present we feel hardly warranted in admitting the identity of the two substances.
Harnack and Witkowski in 1876 ascertained the presence of another alkaloid in the seed, which they called Calabarine. It is nearly insoluble in ether and also very different from physostigmine in its physiological action, but somewhat similar to strychnine. Calabarine is consequently not to be found in those preparations of calabar bean which have been obtained or purified by means of ether.
Hesse (1878) exhausted the cotyledons of Physostigma with petroleum ether, and obtained crystals of a new indifferent substance C₂₆H₄₄+OH₂, which he called Phytosterin. It is closely allied to Cholesterin, but, in its solution in chloroform, devoid of rotatory power and melting at 133°. Cholesterin melts at 145°, and deviates, in its ethereal solution, the ray of polarized light to the left. Phytosterin also occurs in peas; Hesse suggests that the crystallized appearance of alkaloids as prepared by former observers was perhaps due to phytosterin.
From the cotyledons per se, cold water extracts mucilage, precipitable by neutral acetate of lead. The watery infusion contains also albumin, which may be coagulated by heat or by alcohol. The infusion is colourless, does not redden litmus, nor does it contain sugar in appreciable proportion; a few drops of solution of potash cause it to assume an orange colour. An infusion of the shell of the seed is already of this colour, but the tint is intensified by caustic alkali.
[761] Liebig’s Annalen der Chem. u. Pharm. 129 (1864) 115.
[762] Ibid. 141 (1867) 82; Chem. News, 22 March 1867, 149.
[763] Comptes Rendus, lx. (1865) 1194.
[764] Op. cit. chap. 2.
The cotyledons yield to boiling ether ½ to ⅓ per cent. of fatty oil, and after exhaustion by ether and alcohol, afford to cold water 12 per cent. of albuminous and mucilaginous constituents. The proportion of starch according to Teich[765] amounts to 48 per cent., the albuminous matter to 23 per cent. The entire seed furnishes 3 per cent. of ash, chiefly phosphate of potash. These constituents do not widely differ in proportion from those found in the common bean, which yields 23 to 25 per cent. of albuminous matters, and 32 to 38 per cent. of starch, besides 1 to 3 per cent. of oil.
[765] Chemische Untersuchung der Calabarbohne.—Inauguralschrift, St. Petersburg, 1867. We calculate the albuminous matters with reference to Teich’s analysis, which proved the kernels to contain 3·65 per cent. of nitrogen.
The shells of Calabar bean are stated by Fraser to be by no means devoid of active principle.
Vée asserts that if to a solution of eserine, a little potash, lime, or carbonate of sodium be added, there is developed a red colour which rapidly increases in intensity. This colour is transient, passing into yellow, green and blue. If chloroform is shaken with such coloured solution, it takes up the colour; ether on the other hand remains uncoloured.
=Uses=—Calabar has been hitherto chiefly employed as an ophthalmic medicine, for the purpose of contracting the pupil. It has however been occasionally administered in tetanus and in neuralgic, rheumatic, and other diseases.
=Adulteration=—Other seeds are sometimes fraudulently mixed with Calabar beans. We have noticed in particular those of a Mucuna and of the Oil Palm, Elæis guineensis Jacq. The slightest examination suffices for their detection.
KINO
Kino, Gum Kino, East Indian Kino; F. and G. Kino.
=Botanical Origin=—Pterocarpus Marsupium Roxb., a handsome tree 40 to 80 feet high, frequent in the central and southern parts of the Indian Peninsula and also in Ceylon, and affording a valuable timber. In the Government forests of the Madras Presidency, it is one of the reserved trees, the felling of which is placed under restrictions.
Pt. indicus Willd., a tree of Southern India, the Malayan Peninsula and the Indian and Philippine Islands, is capable of yielding kino, and is the source of the small supplies of that drug that were formerly shipped from Moulmein.
Several other plants afford substances bearing the name of Kino, which will be noticed at the conclusion of the present article.
=History=—The introduction of kino into European medicine is due to Fothergill, an eminent physician and patron of economic botany of the last century. The drug which Fothergill examined was brought from the river Gambia in West Africa as a rare sort of Dragon’s Blood, and was described by him in 1757[766] under the name of Gummi rubrum astringens Gambiense. It had been noticed at least twenty years before as a production of the Gambia, by Moore, factor to the Royal African Company, who says that the tree yielding it is called in the Mandingo language Kano.[767] Specimens of this tree were sent to England in 1805 by the celebrated traveller Mungo Park, and recognized some years later as identical with the Pterocarpus erinaceus of Poiret.
It seems probable that African kino continued to reach England for some years, for we find “Gummi rubrum astringens” regularly valued in the stock of a London druggist[768] from 1776 to 1792.
Duncan in the Edinburgh Dispensatory of 1803, while asserting that “kino is brought to us from Africa,” admits that some, not distinguishable from it, is imported from Jamaica. In a later edition of the same work (1811), he says that the African drug is no longer to be met with, and alludes to its place being supplied by other kinds, as that of Jamaica, that imported by the East India Company, and that of New South Wales derived from Eucalyptus resinifera Sm. It will thus be seen that at the commencement of the present century several substances, produced in widely distant regions, bore the name of Kino. That however which was principally used in the place of the old African drug, was East Indian Kino, the botanical origin of which was shown by Wight and by Royle[769] (1844-46) to be Pterocarpus Marsupium Roxb.,—a tree which, curiously enough, is closely allied to the kino tree of Tropical Africa.
This is the drug which is recognized as legitimate kino in all the principal pharmacopœias of Europe. It appears to have been first prepared for the European market in the early part of the present century, on a plantation of the East India Company called Anjarakandy, a few miles from Tellicherry on the Malabar Coast; but as we learn from our friend Dr. Cleghorn, it was not grown there but on the ghats a short distance inland.
=Extraction=—Kino is the juice of the tree, dried without artificial heat.[770] As it exudes, it has the appearance of red currant jelly, but hardens in a few hours after exposure to the air. In the Government forests of the Malabar Coast whence the supplies are obtained, permission to collect the drug is granted on payment of a small fee, and on the understanding that the tapping is performed skilfully and without damage to the timber. The method pursued is this:—A perpendicular incision with lateral ones leading into it, is made in the trunk, at the foot of which is placed a vessel to receive the outflowing juice. This juice soon thickens, and when sufficiently dried by exposure to the sun and air, is packed into wooden boxes for exportation.
=Description=—Malabar kino[771] consists of dark, blackish-red, angular fragments rarely larger than a pea, easily splitting into still smaller pieces, which are seen to be perfectly transparent, of a bright garnet hue, and amorphous under the microscope. In cold water they sink, but partially dissolve by agitation, forming a solution of very astringent taste, and a pale flocky residue. The latter is taken up when the liquid is made to boil, and deposited on cooling in a more voluminous form. Kino dissolves almost entirely in spirit of wine (·838), affording a dark reddish solution, acid to litmus paper, which by long keeping sometimes assumes a gelatinous condition. It is readily soluble in solution of caustic alkali, and to a large extent in a saturated solution of sugar.
[766] Medical Observations and Inquiries, i. (1757) 358.
[767] Travels into the Inland Parts of Africa, by Francis Moore, Lond. 1737. pp. 160. 209. 267.
[768] J. Gurney Bevan, Plough Court, Lombard Street.—The drug was priced in 1787 as having cost 16_s._, and in 1790-92, 21_s._ per lb.
[769] Pharm. Journ. v. (1846) 495.
[770] Cleghorn, Forests and Gardens of South India, 1861. 13.—Also from information communicated by him orally.
[771] Our sample obtained from Pt. Marsupium Roxb. on the Sigúr Ghat, Feb. 1868, was kindly submitted to us by Mr. McIvor of Ootacamund.—We find it to agree with commercial East Indian Kino.
=Chemical Composition=—Cold water forms with kino a reddish solution, which is at first not altered if a fragment of ferrous sulphate is added. But a violet colour is produced as soon as the liquid is cautiously neutralized. This can be done by diluting it with common water (containing bicarbonate of calcium) or by adding a drop of solution of acetate of potassium. Yet the fact of kino developing an intense violet colour in presence of a proto-salt of iron, may most evidently be shown by shaking it with water, and iron reduced by hydrogen. The filtered liquid is of a brilliant violet, and may be evaporated at 100° without turning green; the dried residue even again forms a violet solution with water. By long keeping the violet liquid gelatinizes. It is decolorized by acids, and turns red on addition of an alkali, whether caustic or bicarbonated. Catechu, as well as crystallized catechin, show the same behaviour, but these solutions quickly turn green on exposure to air.
Solutions of acids, of metallic salts, or of chromates produce copious precipitates in an aqueous solution of kino. Ferric chloride forms a dirty green precipitate, and is at the same time reduced to a ferrous salt. Dilute mineral acids or alkalis do not occasion any decided change of colour, but the former give rise to light brownish-red precipitates of Kino-tannic Acid. By boiling for some time an aqueous solution of kino-tannic acid, a red precipitate, Kino-red, is separated.
Kino in its general behaviour is closely allied to Pegu catechu, and yields by similar treatment the same products, that is to say, it affords Pyrocatechin when submitted to dry distillation, and Protocatechuic Acid together with Phloroglucin when melted with caustic soda or potash.
Yet in catechu the tannic acid is accompanied by a considerable amount of catechin, which may be removed directly by exhaustion with ether. Kino, on the other hand, yields to ether only a minute percentage of a substance, whose scaly crystals display under the microscope the character of Pyrocatechin, rather than that of catechin, which crystallizes in prisms. The crystals extracted from kino dissolve freely in cold water, which is not the case with catechin, and this solution assumes a fine green if a very dilute solution of ferric chloride is added, and turns red on addition of an alkali. This is the behaviour of catechin as well as of pyrocatechin; but the difference in solubility speaks in favour of the crystals afforded by kino being pyrocatechin rather than catechin.
We thought pyrocatechin must also occur in the mother plant of kino, but this does not prove to be the case, no indication of its presence being perceptible either in the fresh bark or wood.[772]
Etti (1878) extracted from kino colourless prisms of Kinoïn by boiling the drug with twice its weight of hydrochloric acid, about 1·03 sp. gr. On cooling, kino-red separates, very little of it remaining in solution together with kinoïn. The latter is extracted by exhausting the liquid with ether, which by evaporation affords crystals of kinoïn. They should be recrystallized from boiling water; they agree with the formula C₁₄H₁₂O₆, which is to be regarded as that of a methylated gallic ether of pyrocatechin, viz., C₆H₄ (OCH₃) C₇H₅O₅.
Kinoïn by heating it to 130° C. gives off water and turns red:
2 C₁₄H₁₂O₆ = OH₂ · C₂₈H₂₂O₁₁.
The latter product is an amorphous mass agreeing with kino-red; by heating it at 160-170° it again loses water, thus affording another anhydride.
Etti succeeded in preparing methylic chloride, pyrocatechin CH₄(OH)₂ as well as gallic acid C₇H₆O₅, by decomposing kinoïn.
We have prepared kinoïn from Australian kino (see page 198), but failed in obtaining it from Malabar kino, which however Etti states to have used. Kino affords about 1½ per cent. of kinoïn.
The solutions of kinoïn turn red on addition of ferric salts.
Commercial kino yielded us 1·3 per cent. of ash.
=Commerce=—The quantity of true kino collected in the Madras forests is comparatively small, probably not exceeding a ton or two annually. The drug is often shipped from Cochin.
=Uses=—Kino is administered as an astringent. It is said to be used in the manufacture of wines, and it might be employed if cheap enough in tanning and dyeing.
Other sorts of Kino.
1. Butea Kino, Butea Gum, Bengal Kino, Palas or Pulas Kino, Gum of the Palas or Dhak Tree.
This is an exudation from Butea frondosa Roxb. (Leguminosæ), a tree of India and Burma, well known under the name of Palas or Dhak, and conspicuous for its splendid, large, orange, papilionaceous flowers.[773] According to Roxburgh it flows during the hot season from natural fissures or from wounds made in the bark, as a red juice which soon hardens into a ruby-coloured, brittle, astringent gum.
[772] We have to thank Mr. Broughton, late of the Cinchona Plantations, Ootacamund, for determining this point. In the bark almost saturated with fresh liquid kino, he utterly failed to obtain any indication of pyrocatechin by the tests which he found to render it easily evident in dry kino.
[773] See Nees von Esenbeck, Plantæ medicinales, Düsseldorf, iii. (1833) tab. 79.
Authentic specimens of this kino have been placed at our disposal by Mr. Moodeen Sheriff of Madras and by Dr. J. Newton of Bellary. That received from the first-named gentleman consists of flattish, angular fragments (the largest about ½ an inch across) and small drops or tears of a very dark, ruby-coloured gum, which when held to the light is seen to be perfectly transparent. The flat pieces have been mostly dried on leaves, an impression of the veins of which they retain on one side, while the other is smooth and shining. The substance has a pure astringent taste, but no odour. It yielded us 1·8 per cent. of ash and contained 13·5 per cent. of water. Ether removes from it a small quantity of pyrocatechin. Boiling alcohol dissolves this kino to the extent of 46 per cent.; the solution which is but little coloured, produces an abundant greyish-green precipitate with perchloride of iron, and a white one with acetate of lead. It may be hence inferred that a tannic acid, probably kino-tannic acid, constitutes about half the weight of the drug, the remainder of which is formed of a soluble mucilaginous substance which we have not isolated in a state of purity. By submitting the Butea kino of Mr. Moodeen Sheriff to dry distillation we obtained pyrocatechin.
The sample from Dr. Newton is wholly in transparent drops and stalactitic pieces, considerably paler than that just described, but of the same beautiful ruby tint. The fragments dissolve freely and almost completely in cold water, the solution being neutral and exhibiting the same reactions as the former sample.
Butea kino, which in India is used in the place of Malabar kino, was long confounded with the latter by European pharmacologists, though the Indian names of the two substances are quite different. It is not obtained exclusively from B. frondosa, the allied B. superba Roxb. and B. parviflora Roxb. affording a similar exudation.
2. African or Gambia Kino.—Of this substance we have a specimen collected by Daniell[774] in the very locality whence it was obtained by Moore in 1733 (see p. 195), and by Park at the commencement of the present century. The tree yielding it, which still bears the Mandingo name Kano, and grows to a height of 40 to 50 feet, is Pterocarpus erinaceus Poiret, a native of Tropical Western Africa from Senegambia to Angola. The juices exude naturally from crevices in the bark, but much more plentifully by incisions; it soon coagulates, becoming deep blood-red and remarkably brittle. That in our possession is in very small, shining, angular fragments, which in a proper light appear transparent and of a deep ruby colour. In solubility and chemical characters, we can trace no difference between it and the kino of the allied Pt. Marsupium Roxb. This kino does not now find its way to England as a regular article of trade. From the statement of Welwitsch, it appears that the Portuguese of Angola employ it under the name of Sangue de Drago.[775]
3. Australian, Botany Bay, or Eucalyptus Kino.—For some years past, the London drug market has been supplied with considerable quantities of kino from Australia; in fact at one period this kino was the only sort to be purchased.
[774] See his paper On the Kino Tree of West Africa, Pharm. Journ. xiv. (1855) 55.
[775] Madeiras e Drogas medicinaes de Angola, Lisboa, 1862, 37.
As it is the produce of numerous species of Eucalyptus, it is not surprising that it presents considerable diversity of appearance. The better qualities closely agree with Pterocarpus kino. They are in dark reddish-brown masses or grains, which when in thin fragments are seen to be transparent, of a garnet red hue and quite amorphous. The substance is mostly collected by the sawyers and wood-splitters. It is found within the trunks of trees of all sizes, in flattened cavities of the otherwise solid wood which are often parallel to the annual rings. In such place the kino, which is at first a viscid liquid, becomes inspissated and subsequently hard and brittle. It may also be obtained in a liquid state by incisions in the stems of growing trees: such liquid kino has occasionally been brought into the London market; it is a viscid treacle-like fluid, yielding by evaporation about 35 per cent. of solid kino.[776]
Authentic specimens of the kino of 16 species of Eucalyptus sent from Australia by F. von Müller, have been examined by Wiesner of Vienna.[777] He found the drug to be in most cases readily soluble in water or in spirit of wine, the solution being of a very astringent taste. The solution gave with sulphuric acid a pale red, flocculent precipitate of Kino-tannic Acid; with perchloride of iron (as in common kino) a dusky greenish precipitate,—except in the case of the kino of E. obliqua L’Hér. (Stringy-bark Tree), the solution of which was coloured dark violet.
Wiesner further states, that Eucalyptus kino affords a little Catechin[778] and Pyrocatechin. It contains no pectinous matter, but in some varieties a gum-like that of Acacia. In one sort, the kino of E. gigantea Hook,[779] gum is so abundant that the drug is nearly insoluble in spirit of wine.
By Etti’s process, as given at page 197, we obtained kinoïn from an Australian Kino, which contained numerous fragments of the wood. We noticed that both Australian and Malabar kino emitted a somewhat balsamic odour, when they were treated with hydrochloric acid.
From this examination, it is evident that the better varieties of Eucalyptus kino, such for instance as those derived from E. rostrata Schlecht. (Red or White Gum, or Flooded Gum of the colonists), E. corymbosa Sm. (Blood-wood) and E. citriodora Hook., possess the properties of Pterocarpus kino and might with no disadvantage be substituted for it.
[776] Victoria Exhibition, 1861.—Jurors’ Report on Class 3. p. 59.
[777] Zeitschrift des österreich. Apotheker-Vereines ix. (1871) 497; Pharm. Journ. Aug. 5, 1871. 102.
[778] In our opinion this is doubtful.
[779] Bentham unites this species to E. obliqua L’Hér (Flor. Austr. iii. 204).
LIGNUM PTEROCARPI
Lignum Santalinum rubrum, Santalum rubrum; Red Sanders Wood, Ruby Wood; F. Bois de Santal rouge; G. Rothes Sandelholz, Caliaturholz.
=Botanical Origin=—Pterocarpus santalinus Linn. fil.—A small tree not often exceeding 3½ to 4 feet in girth, and 20 to 25 feet in height; it is closely related to Pt. Marsupium Roxb., from which it differs chiefly in having broader leaflets always in threes. It is a native of the southern part of the Indian Peninsula, as Canara, Mysore, Travancore and the Coromandel Coast, but also occurs in Mindanao, in the southern Philippines. In India the districts in which the wood is at present chiefly obtained are the forests of the southern portion of the Kurnool Hills, Cuddapah and North Arcot (W. and N.W. of Madras). The tree is now being raised in regular plantations.[780]
The wood is a staple article of produce, and the felling of the trees is strictly controlled by the forest inspectors. The fine trunk-wood is highly valued by the natives for pillars in their temples and other buildings, as well as for turnery. The stumps and roots are exported to Europe as a dye-stuff, mostly from Madras.
=History=—It is difficult to tell whether the appellation Red Sandal-wood used in connexion with Yellow and White Sandal-wood by some of the earlier writers on drugs, was intended to indicate the inodorous dyewood under notice or the aromatic wood of a species of Santalum. Yet when Marco Polo[781] alludes to the sandal-wood imported into China, and to the red sandal (“Cendal vermeil”) which grows in the island of Necuveran (Nicobar), it is impossible to doubt that he intended by this latter name some such substance as that under notice.
Garcia de Orta, who wrote at Goa in the middle of the 16th century, clearly distinguished the fragrant sandal of Timor from the red inodorous wood of Tenasserim and the Coromandel Coast. It is remarkable that the wood of Pt. santalinus is distinguished to the present day in all the languages of India by names signifying red-coloured sandal-wood, though it has none whatever of the peculiarities of the odorous wood of Santalum. Red Sanders Wood was formerly supposed to possess medicinal powers: these are now disregarded, and it is retained in use only as a colouring agent.
During the middle ages, it was used as well as alkanet for culinary purposes, such as the colouring of sauces and other articles of food. The price in England between 1326 and 1399 was very variable, but on an average exceeded 3_s._ per lb.[782] Many entries for the purchase of Red Sanders along with spices and groceries, occur in the accounts of the Monastery of Durham, A.D. 1530-34.[783]
=Description=—The wood found in English commerce is mostly that of the lower parts of the stem and that of the thickest roots. It appears in the market in ponderous, irregular logs, rarely exceeding the thickness of a man’s thigh and commonly much smaller, 3, 4 or 5 feet in length; they are without bark or sapwood, and are externally of a dark colour. The internal wood is of a deep, rich, blood-red, exhibiting in transverse section zones of a lighter tint, and taking a fine polish.
At the present day, druggists generally buy the wood rasped into small chips, which are of a deep reddish-brown hue, tasteless and nearly without odour.
[780] (Beddome), Report of the Conservator of Forests, for 1869-70, Madras, 1870, pp. 3. 39. 123; for figure of the tree, see Flora Sylvatica of Southern India of the same author, tab. xxii.
[781] Pauthier, Livre de Marco Polo, 580—Pt. indicus Willd. grows in the adjacent Andaman Islands.
[782] Rogers, Agriculture and Prices in England, 1866, i. 631, ii. 545, &c.—The average price of a sheep during the same period was about 1_s._ 6_d._
[783] Durham Household Book, Surtees Soc. 1844. 215; also Pegge, Form of Cury, Lond. 1780. p. xv.
=Microscopic Structure=—The wood is built up for the greater part of long pointed cells, having thick walls (libriform). Through this ligneous tissue, there are scattered small groups of very large vessels. In a direction parallel to the circumference of the stem, there are less coloured small parenchymatous layers, running from one vascular bundle to another. The whole tissue is finally traversed by very narrow medullary rays, which are scarcely perceptible to the unaided eye. The parenchymatous cells are each loaded with one crystal of oxalate of calcium, which are so large that, in a piece of the wood broken longitudinally, they may be distinguished without a lens. The colouring matter is contained especially in the walls of the vessels and the ligneous cells.
=Chemical Composition=—Cold water or fatty oil (almond or olive) abstracts scarcely anything from the wood, and hot water but very little. On the other hand, ether, spirit of wine, alkaline solutions, or concentrated acetic acid, readily dissolves out the colouring matter. Essential oils of bitter almond or clove take up a good deal of the red substance; that of turpentine none at all. This resinoid substance, termed Santalic Acid or Santalin,[784] is said to form microscopic prismatic crystals of a fine ruby colour, devoid of odour and taste, fusing at 104° C., insoluble in water but neutralizing alkalis and forming with them uncrystallizable salts.
Weidel (1870) exhausted the wood with boiling water, containing a little potash, and obtained by means of hydrochloric acid a red precipitate, which was redissolved in boiling alcohol and then furnished colourless crystals of Santal, C₈H₆O₃. They are devoid of odour or taste, not soluble in water, benzol, chloroform, bisulphide of carbon, and but sparingly in ether. Santal yields with potash a faintly yellow solution which soon turns red and green. The wood afforded Weidel not more than 3 per mille of santal.
Cazeneuve (1874)[785] mixed 4 parts of the wood with 1 part of slaked lime, and exhausted the dried powder with ether containing a little alcohol. After the evaporation of the ether, a small amount of colourless crystals of Pterocarpin was obtained, which were purified by recrystallization from boiling alcohol. They melt at 83° C., and are abundantly soluble in chloroform, in bisulphide of carbon, very little in cold alcohol, not at all in water. Pterocarpin agrees with the formula C₁₇H₁₆O₅. It yields a red solution with concentrated sulphuric acid, and a green with nitric acid 1·4 sp. gr. By submitting it to destructive distillation pyrocatechin appears to be formed.
Franchimont (1879) assigns the formula C₁₇H₁₆O₆ to another principle of Red Sanders Wood, which he isolated by means of alcohol. It is an amorphous substance, melting at 105°. By extracting the wood with a solution of carbonate of sodium, Hagenbach (1872) obtained a fluorescent solution. Red Sanders Wood yielded us of ash only 0·8 per cent.
=Commerce=—In the official year 1869-70, Red Sanders Wood produced to the Madras Government a revenue of 26,015 rupees (£2,601). The quantity taken from the forests was reported as 1,161,799 lb.
[784] Gmelin, Chemistry, xvi. (1864) 259; the formula assigned to santalic acid (C₁₅H₁₄O₅) appears to be doubtful. Weidel in proposing the formula C₁₄H₁₂O₄ points out that it may be allied to alizarin, C₁₄H₈O₄.
[785] See Dictionnaire de Chimie, art. Santaline, p. 1434, and for particulars: Cazeneuve, Recherche et extraction des alcaloïdes, etc. Paris, 1875. 66. It would appear that the author obtained about 4 per mille of pterocarpin from the wood.
=Uses=—Red Sanders Wood is scarcely employed in pharmacy except for colouring the Compound Tincture of Lavender; but it has numerous uses in the arts. The latter applies also to the wood of Pterocarpus angolensis DC., which is largely exported from the French colony of Gaboon; it is the “Santal rouge d’Afrique of the French,” or Barwood of the English commerce.
BALSAMUM TOLUTANUM
Balsam of Tolu; F. Baume de Tolu; G. Tolubalsam.
=Botanical Origin=—Myroxylon Toluifera H B K. (Toluifera Balsamum Miller, Myrospermum toluiferum A. Rich.),[786] an elegant and lofty evergreen tree with a straight stem, often as much as 40 to 60 feet from the ground to the first branch. It is a native of Venezuela, and New Granada,—probably also of Ecuador and Brazil.
=History=—The first published account of Balsam of Tolu, is that of the Spanish physician Monardes, who in his treatise on the productions of the West Indies, which in its complete form first appeared at Seville in 1574,[787] relates how the early explorers of South America observed that the Indians collected this drug by making incisions in the trunk of the tree. Below the incisions they affixed shells of a peculiar black wax to receive the balsam, which being collected in a district near Cartagena called Tolu, took its name from that place. He adds that it is much esteemed both by Indians and Spaniards, that the latter buy it at a high price, and that they have lately brought it to Spain, where it is considered to be as good as the famous Balsam of Mecca.
Francisco Hernandez, who lived in 1561-1577 in Mexico, stated[788] that the balsam of the province of Tolu was thought to be quite as useful as, if not superior to, “balsamum indicum,” i.e. peruvianum.
A specimen agreeing with this description was given to Clusius[789] in 1581 by Morgan, apothecary to Queen Elizabeth, but the drug was certainly not common till a much later period. In the price-list of drugs of the city of Frankfort of 1669, Balsamus tolutanum (sic) is expressly mentioned,[790] but there can be but little doubt that Balsamum Americanum resinosum[791] or siccum or durum as occurring in many other tariffs of the 17th century, printed in Germany, was also the balsam under notice;[792] in a similar list emanating from the city of Basle in 1646,[793] we noticed B. indicum album, B. peruvianum and B. siccum,—the last with the explanatory words, “trockner Balsam in der Kürbsen” (i.e. in gourds), meaning probably balsam of Tolu.
[786] Fig. in Bentley and Trimen, Med. Plants, part 23 (1877) under the name of Toluifera Balsamum. Though the change of names may be justified by the strict rules of priority, we are of opinion that at present it would be fraught with more of inconvenience than advantage.—Myroxylon punctatum Klotzsch, a tree stated to grow nearly all over the northern part of South America, is referred to the same species by Bentley and Trimen.
[787] Historia de las cosas que se traen de nuestras Indias occidentales, cap. del Balsamo de Tolu.
[788] Nova Plantarum, animal. et mineral. mexicanorum. Historia, Reccho’s edition, Romæ, 1651. fol. 53.
[789] Exoticor. etc. 1605. lib. x. fol. 305.
[790] Pharm. Journ. vi. (1876) 102.
[791] Pharmaceutical tariff (“Taxa”) of the city of Wittenberg 1632 (in the Hamburg library).
[792] Flückiger, Documente zur Geschichte der Pharmacie, Halle, 1876. 49. 50. 53.—Balsamum Peruvianum first occurs in the tariff of the city of Worms of 1609.—Documente, p. 39; Pharm. Journ. l. c.
[793] Contained in the Medicine Tariffs, in the library of the British Museum, bound together in one volume ({777. c.}/5). They include Schweinfurt 1614, Bremen 1644, Basle 1647, Rostock 1659, Quedlinburg 1665, Frankfort on Main 1669 (quoted above).
As to the tree, of which Monardes figured a broken pod, leaflets of it, marked 1758, exist in Sloane’s herbarium. Humboldt and Bonpland saw it in several places in New Granada during their travels (1799-1804), but succeeded only in gathering a few leaves. Among recent collectors, Warszewicz, Triana, Sutton Hayes, and Seemann were successful only in obtaining leaves. Weir in 1863 was more happy, for by causing a large tree of nearly 2 feet diameter to be felled, he procured good herbarium specimens including pods, but no flowers. Owing to this tree having been much wounded for balsam, its foliage and fruits were singularly small and stunted, and its branches overgrown with lichens.
That which botanists had failed to do, has been accomplished by an ornithologist, Mr. Anton Goering, who, travelling in Venezuela to collect birds and insects, made it a special object, at the urgent request of one of us (H.), to procure complete specimens of the Balsam of Tolu tree. By dint of much perseverance and by watching for the proper season, Mr. Goering obtained in December 1868 excellent flowering specimens and young fruits, and subsequently mature seeds from which plants have been raised in England, Ceylon and Java.
=Extraction=—The most authentic information we possess on this subject is derived from Mr. John Weir, plant collector to the Royal Horticultural Society of London, who when about to undertake a journey to New Granada in 1863, received instructions to visit the locality producing Balsam of Tolu. After encountering considerable difficulties, Mr. Weir succeeded in observing the manner of collecting the balsam in the forest near Plato, on the right bank of the Magdalena. Mr. Weir’s information[794] may be thus summarized:—
The balsam tree has an average height of 70 feet with a straight trunk, generally rising to a height of 40 feet before it branches. The balsam is collected by cutting in the bark two deep sloping notches, meeting at their lower ends in a sharp angle. Below this =V=-shaped cut, the bark and wood is a little hollowed out, and a calabash of the size and shape of a deep tea-cup is fixed. This arrangement is repeated, so that as many as twenty calabashes may be seen on various parts of the same trunk. When the lower part has been too much wounded to give space for any fresh incisions, a rude scaffold is sometimes erected, and a new series of notches made higher up. The balsam-gatherer goes from time to time round the trees with a pair of bags of hide, slung over the back of a donkey, and empties into them the contents of the calabashes. In these bags the balsam is sent down to the ports where it is transferred to the cylindrical tins in which it reaches Europe. The bleeding of the trees goes on for at least eight months of the year, causing them ultimately to become much exhausted, and thin in foliage.
In some districts, as we learn from another traveller, it is customary to let the balsam flow down the trunk into a receptacle at its base, formed of the large leaf of a species of Calathea.
[794] Journ. of the R. Hort. Soc., May 1864; Pharm. Journ. vi. (1865) 60.
From the observations of Mr. Weir, it appears that the balsam tree is plentifully scattered throughout the Montaña around Plato and other small ports on the right bank of the Magdalena. He states that he saw at least 1,500 lb. of the drug on its way for exportation. From another source, we know that it is largely collected in the valley of the Sinu, and in the forests lying between that river and Cauca. None is collected in Venezuela.
=Description=—Balsam of Tolu freshly imported is a light brown, slow-flowing resin, soft enough to be impressible with the finger, but viscid on the surface.[795] By keeping, it gradually hardens so as to be brittle in cold weather, but it is easily softened by the warmth of the hand. Thin layers show it to be quite transparent and of a yellowish brown hue. It has a very agreeable and delicate odour, suggestive of benzoin or vanilla, especially perceptible when the resin is warmed, or when its solution in spirit is allowed to evaporate on paper. Its taste is slightly aromatic with a barely perceptible acidity, though its alcoholic solution decidedly reddens litmus.
In very old specimens, such as those which during the last century reached Europe in little calabashes[796] of the size and shape of an orange, the balsam is brittle and pulverulent, and exhibits when broken a sparkling, crystalline surface. This old balsam is of a fine deep amber tint and superior fragrance.
When Balsam of Tolu is pressed between two warmed plates of glass so as to obtain it in a thin even layer, and then examined with a lens, it exhibits an abundance of crystals of cinnamic acid. Balsam of Tolu dissolves easily and completely in glacial acetic acid, acetone, alcohol, chloroform or solution of caustic potash; it is less soluble in ether, scarcely at all in volatile oils, and not in benzol or bisulphide of carbon. The solution in acetone is devoid of rotatory power in polarized light.
=Chemical Composition=—The balsam consists partly of an amorphous resin, not soluble in bisulphide of carbon, which is supposed to be the same as the dark resin precipitated by the bisulphide from balsam of Peru. Scharling (1856) assigned the formula C₁₈H₂₀O₅ to that part of the balsam which is soluble in potash.
If Tolu balsam is boiled with water, it yields to it cinnamic and benzoic acid, which we have (1877) perfectly succeeded in separating by repeated recrystallization from water; we have before us good specimens of either, showing not only different melting points (133° C. and 121° C.), but as to our crystals of benzoïc acid, isolated from the balsam as stated above, we find that they also do not evolve bitter almond oil when mixed with sulphuric acid and chromate of potassium. The acids may also be removed by boiling bisulphide of carbon.
Busse[797] showed that benzylic ethers of both benzoic and cinnamic acid are also constituents of the balsam, the cinnamate of benzyl being present in larger quantity.
Upon distilling the balsam with water, it affords 1 per cent. of Tolene, C₁₀H₁₆, boiling at about 170° C. This liquid rapidly absorbs oxygen from the air. By destructive distillation, the balsam affords the same substances as those obtainable from balsam of Peru, among which Phenol and Styrol have been observed.
[795] I have seen it imported very fluid into London by way of New York.—Sept. 1878.—F. A. F.
[796] The gourds, “Kürbsen,” of the list of Basle of 1647.
[797] Berichte der Deutschen Chemischen Gesellschaft, 1876. 833.
=Commerce=—The balsam is exported from New Granada, packed in cylindrical tins holding about 10 lb. each. The quantity shipped from Santa Marta in 1870 was 2,002 lb.; in 1871, 2,183 lb.; in 1872, 1,206 lb. In 1876 from the port of Savanilla 27,180 kilogrammes are stated to have been exported.
=Uses=—Balsam of Tolu has no important medicinal properties. It is chiefly used as an ingredient in a pleasant-tasting syrup and in lozenges.
=Adulteration=—We have twice met with spurious Balsam of Tolu, but in neither instance did the fraudulent drug bear any great resemblance to the genuine.
Colophony, which might be mixed with the balsam, can be detected by warm bisulphide of carbon which dissolves it, but removes from the pure drug almost exclusively cinnamic and benzoic acid.
BALSAMUM PERUVIANUM.
Balsam umindicum nigrum; Balsam of Peru; F. Baume de Pérou, Baume de San Salvador; G. Perubalsam.
=Botanical Origin=—Myroxylon Pereiræ Klotzsch (Myrospermum Pereiræ Royle), a tree attaining a height of about 50 feet, and throwing out spreading, ascending branches at 6 to 10 feet from the ground.[798]
It is found in a small district of the State of Salvador in Central America (formerly part of Guatemala), lying between 13°·35 and 14°·10 N. lat., and 89° and 89°·40 W. long., and known as the Costa del Balsamo or Balsam Coast. The trees grow naturally in the dense forests; those from which the balsam is obtained are, if in groups, sometimes enclosed, in other cases only marked, but all have their distinct owners. They are occasionally rented for a term of years, or a contract is made for the produce of a certain number.
The principal towns and villages around which balsam is produced, are the following:—Juisnagua, Tepecoyo or Coyo, Tamanique, Chiltiuapan, Talnique, Jicalapa, Teotepeque, Comasagua and Jayaque. All the lands on the Balsam Coast are Indian Reservation Lands.
The Balsam of Peru tree was introduced in 1861 into Ceylon, where it flourishes with extraordinary vigour.
[798] We are not yet prepared to accept the opinion of Baillon, that M. Pereiræ is specifically identical with M. Toluifera, though we admit they are very closely related. According to our observations, the two trees exhibit the following differences:—
M. Toluifera. | M. Pereiræ. | Trunk tall and bare, | Trunk throwing off branching at 40 to 60 feet | ascending branches from the ground, and forming | at 6 to 10 feet from a roundish crown of foliage. | the ground. | Calyx rather tubular. | Calyx widely cup-shaped, shallow. | Racemes dense, | Racemes loose, 3 to 4½ inches long. | 6 to 7 inches long. | Legume scarcely narrowed | Legume much narrowed towards the stalk-end. | towards the stalk-end.
See also Bentley and Trimen, Medicinal Plants, part 10 (1876), Toluifera Pereiræ.
=History=—As in the case of Balsam of Tolu, it is to Monardes of Seville that we are indebted for the earliest description of the drug under notice. In a chapter headed Del Balsamo,[799] he states that at the time he wrote (1565) the drug was not new, for that it had been received into medicine immediately after the discovery of New Spain. As the conquest of Guatemala took place about 1524, we may conclude that the balsam was introduced into Europe soon afterwards.
Monardes further adds, that the balsam was in such high estimation that it sold for 10 to 20 ducats (£4 10_s._ to £9) the ounce; and that when taken to Rome, it fetched even 100 ducats for the same quantity. The inducement of such enormous prices brought plenty of the drug to Europe, and its value, as well as its reputation, was speedily reduced.
The description given by Monardes of extracting the balsam by boiling the chopped wood of the trunk and branches, raises a doubt as to whether the drug he had in view was exactly that now known; but he never was in America, and may have been misinformed. Evidence that our drug was in use, is afforded by Diego Garcia de Palacio, who, in his capacity of Auditor of the Royal Audiencia of Guatemala, wrote an account to Philip II., king of Spain, describing the geography and productions of this portion of his majesty’s dominions. In this interesting document, which bears date 1576 and has only recently been published,[800] Palacio tells the king of the great balsam trees of Guaymoco and of the coasts of Tonala,[801] and of the Indian method of promoting the exudation of the balsam by scorching the trunk of the tree. Prior to the conquest of the country by the Spaniards and for a short time after, balsam formed part of the tribute paid to the Indian chiefs of Cuscatlan, to whom it was presented in curiously ornamented earthen jars.
The idea of great virtues attaching to the balsam is shown by the fact that, in consequence of representations made by missionary priests in Central America, Pope Pius V. granted a faculty to the Bishops of the Indies, permitting the substitution of the balsam of Guatemala for that of Egypt, in the preparation of the chrism used in the Roman Catholic Church. This document, bearing date August 2, 1571, is still preserved in the archives of Guatemala.[802]
In the 16th century, the balsam tree grew in the warm regions of Panuco and Chiapan in Mexico, whence it was introduced into the famous gardens of Hoaxtepec near the city of Mexico, described by Cortes in his letter to Charles V. in 1552.[803]
A rude figure of the tree, certainly a Myroxylon and probably the species under notice, was published in the Thesaurus Rerum Medicarum Novæ Hispaniæ of Hernandez,[804] who also says that it had been transferred to the “Hoaxtepecences hortos” of the Mexican kings “delitiarum et magnificentiæ gratia.”
[799] Occurring in the first book of the work quoted in the Appendix, which was published separately at Seville in 1565.
[800] Squier, Documents and Relations concerning the Discovery and Conquest of America, New York, 1859.—Frantzius, San Salvador und Honduras im Jahre 1576. Berlin, 1873.
[801] The ancient name of the Balsam Coast; Guaymoco is a village between Sonsonate and San Salvador. The pillars of wood of Myroxylon in the church are, perhaps, says Squier, the very same as those mentioned with admiration by Palacio.
[802] It may be found in extenso in the original Latin in _Pharm. Journ._ ii. (1861) 447 as well as in Hanbury’s Science Papers, 1876. 294.
[803] Clavigero, Hist. of Mexico, English trans. i. (1787) pp. 32. 379.
[804] Rome, 1628; 2nd ed. 1651. fol. 51; the book written in the town of Mexico, bears at the same time also the title given in the Appendix.
Balsam of Peru was well known in German pharmacy in the beginning of the 17th century (see article Balsamum Tolutanum).
The exports of Guatemala being shipped chiefly at Acajutla, were formerly carried to Callao, the port of Lima, whence they were transmitted to Spain. This circumstance led to the balsam acquiring the misleading name of Peru, and in part to the notion that it was a production of South America.
The history of Balsam of Peru was much amplified by a communication of the late Dr. Charles Dorat, of Sonsonate, Salvador, in 1860 to the American Journal of Pharmacy, and by still further information accompanied by drawings and specimens, transmitted to one of us in 1863.[805] These statements have lastly been confirmed again on the spot by Mr. Theophilus Wyss, a Swiss apothecary, established in San Miguel la Union, San Salvador.[806]
=Extraction of the Balsam=—Early in November or December, or after the last rains, the stems of the balsam trees are beaten with the back of an axe, a hammer or other blunt instrument, on four sides, a similar extent of bark being left unbruised between the parts that are beaten. The bark thus injured soon cracks in long strips, and may be easily pulled off. It is sticky as well as the surface below it, and there is a slight exudation of fragrant resin, but not in sufficient quantity to be worth collecting. To promote an abundant flow, it is customary, five or six days after the beating, to apply lighted torches or bundles of burning wood to the injured bark, whereby the latter becomes charred. About a week later, the bark either drops or is taken off, and the stem commences to exude the balsam. This is collected by placing rags (of any kind or colour), so as entirely to cover the bare wood. As these rags in the course of some days become saturated with the exudation, they are collected, thrown into an earthen vessel of water, and gently boiled and stirred until they appear nearly clean, the balsam separating and sinking to the bottom. This process goes on for some hours, the exhausted rags being from time to time taken out, and fresh ones thrown in. As the rags are removed they are wrung out in a sort of rope bag, and the balsam so saved is added to the stock. When the boiler has cooled, the water is decanted, and the balsam is poured into tecomates or gourds, ready for the market.
The balsam prepared by means of rags is termed “balsamo de trapo;” a little balsam of inferior quality is also produced, according to Wyss, by boiling the bark with water. This method affords “Tacuasonte” or “balsamo de cascara,” which is sometimes mixed with the balsamo de trapo. Tacuasonte means prepared without fire.
[805] Hanbury in Pharm. Journ. v. (1864) 241. 315; also Science Papers, 294-309.
[806] See my paper, with map, in Schweizerische Wochenschrift für Pharmacie, 1878. 219 (Library of the Pharm. Soc., London).—In the Catalogue of the contributions of San Salvador to the Paris exhibition, p. 33, Dr. D. J. Guzman gives: “Détails sur le moyen, d’extraire et travailler le Balsamo negro du Salvador,” which are far from satisfactory.—F. A. F.
The Indians work a tree a second year, by bruising the bark that was left untouched the previous year. As the bark is said to be renewed in the short space of two years, it is possible to obtain from the same tree an annual yield of about 2 lb. of balsam for many years, provided a few years of rest be occasionally allowed. Clay or earth is sometimes smeared over the bare wood.
The trees sometimes exude spontaneously a greenish gum-resin of slightly bitter taste, but totally devoid of balsamic odour. It has been analyzed by Attfield (see opposite page).
=Secretion of the Balsam=—No observations have yet been made as to the secretion of the balsam in the wood, or the part that is played by the operation of scorching the bark. Neither the unscorched bark nor the wood, as we have received them, possess any aromatic odour.
The old accounts speak of a very fragrant resin, far more valuable than the ordinary balsam, obtained by incisions. We have made many inquiries for it, but without the least success. Such a resin is easily obtainable from the trunk of M. Toluifera.
=Description=—Balsam of Peru is a liquid having the appearance of molasses, but rather less viscid. In bulk it appears black, but when examined in a thin layer, it is seen to be of a deep orange-brown and perfectly transparent. It has a balsamic, rather smoky odour, which is fragrant and agreeable when the liquid is smeared on paper and warmed. It does not much affect the palate, but leaves a disagreeable burning sensation in the fauces.
The balsam has a sp. gr. of 1·15 to 1·16. It may be exposed to the air for years without undergoing alteration or depositing crystals. It is not soluble in water, but yields to it a little cinnamic and traces of benzoic acid; from 6 to 8 parts of crystallized carbonate of sodium are required to neutralize 100 parts of the balsam. It is but partially and to a small extent dissolved by dilute alcohol, benzol, ether or essential or fatty oils, not at all by petroleum ether. The balsam mixes readily with glacial acetic acid, anhydrous acetone, absolute alcohol or chloroform. Its rotatory power is very insignificant.
=Chemical Composition=—The peculiar process by which balsam of Peru is obtained, causes it to contain a variety of substances not found in the more natural resin of Myroxylon Toluifera; hence the two drugs, though derived from plants most closely allied, possess very different properties.
Three parts of the balsam mix readily with one part of bisulphide of carbon, yet a further addition of the latter will cause the separation of a brown flocculent resin. If the balsam be mixed with thrice its weight of bisulphide, a coherent mass of dark resin, sometimes amounting to about 38 per cent. of the balsam, is precipitated. The bisulphide of carbon forms then a perfectly transparent brown liquid. If this solution is shaken with water, the latter removes Cinnamic and Benzoic acids. To separate them, ammonia is cautiously added, yet not in excess.[807] The solution of cinnamate and benzoate thus obtained and duly concentrated, yields both these acids in white crystals on addition of acetic or hydrochloric acid.
[807] By saturating the acid aqueous liquid with ammonia, it assumes a transient bright yellow hue; an excess of ammonia transforms the whole mixture into an emulsion, from which the cinnameïn again separates but imperfectly.
The resin separated by means of bisulphide of carbon as above stated, is a black brittle amorphous mass, having no longer the specific odour of the balsam. It is soluble in caustic alkalis, also in alcohol; the solution in the latter which may be considerably purified by charcoal, reddens litmus, and is abundantly precipitated by an alcoholic solution of neutral acetate of lead. Kachler (1869) by melting this resin with potash obtained about ⅔ of its weight of protocatechuic acid.[808] By destructive distillation, it furnishes benzoic acid, styrol, C₈H₈, and toluol, C₇H₈.
As to the solution obtained with bisulphide of carbon, it forms, after the bisulphide has evaporated, a brownish aromatic liquid of about 1·1 sp. gr., termed Cinnameïn. This substance may also be obtained by distillation, yet less easily, on account of its very high boiling point, about 300° C.
Cinnameïn, C₁₆H₁₄O₂, is resolved by concentrated caustic lye into benzylic alcohol, C₇H₁₄O₂, and cinnamic acid, C₉H₈O₂, whence it follows that cinnameïn is Benzylic Cinnamate. This is, according to Kraut (1858, 1869, 1870) and to Kachler (1869, 1870), the chief constituent of the balsam. The former chemist obtained from it nearly 60 per cent. cinnameïn. Kachler assigns to the balsam the following composition: 46 per cent. of cinnamic acid, 32 of resin, 20 of benzylic alcohol. These latter figures however are not quite consistent: 46 parts of cinnamic acid (molecular weight = 148) would answer to 73 parts of benzylic cinnamate; and 20 parts of benzylic alcohol require on the other hand only (mol. weight = 108) 27·4 parts of cinnamic acid in order to form benzylic cinnamate (mol. = 238).
Benzylic cinnamate, prepared as above stated, is a thick liquid, miscible both with ether or alcohol, not concreting at -12° C., boiling at 305° C., yet under ordinary circumstances not without decomposition. By exposure to air, it slowly acquires an acid reaction; by prolonged action of potash, especially in an alcoholic solution, toluol is also formed. In this process, cinnamate of potassium finally forms a crystalline mass, while an oily mixture of benzylic alcohol and toluol, the so-called “Peruvin” constitutes the liquid part of the whole.
Grimaux (1868) has artificially prepared benzylic cinnamate by heating an alkaline cinnamate with benzylic chloride. Thus obtained, that substance forms crystals, which melt at 39° C., and boil at 225 to 235° C. They consequently differ much from cinnameïn.
Delafontaine (1868) is of the opinion, that cinnameïn contains besides benzylic cinnamate, cinnamylic cinnamate, C₃₆H₃₂O₄, the same substance as described under the name of styracin in the article Styrax liquida. He states that he obtained benzylic and cinnamylic alcohol when he decomposed cinnameïn by an alkali. The two alcohols however were separated only by fractional distillation.
From the preceding investigations it must be concluded, that the bark of the tree contains resin and probably benzylic cinnamate. The latter is no doubt altered by the process of collecting the balsam, which is followed on the Balsam Coast. To this are probably due the free acids in the balsam and its dark colour.
Another point of considerable interest is the fact, that the tree exudes a gum-resin, containing according to Attfield 77·4 per cent. of resin,[809] which is non-aromatic and devoid of cinnamic acid, and therefore entirely distinct from balsam of Peru. The leaves of the tree contain a fragrant oil.
[808] Numerous resins as benzoin, guaiacum, dragon’s blood, myrrh, etc., and many other substances are capable of affording the same acid.
[809] Pharm. Journ. v. (1864) 248.
=Commerce=—The balsam is shipped chiefly at Acajutla. It used formerly to be packed in large earthenware jars, said to be Spanish wine-jars, which, wrapped in straw, were sewed up in raw hide. These packages have of late been superseded by metallic drums, which have the advantage of being much less liable to breakage. We have no exact statistics as to the quantity exported from Central America. In the catalogue of San Salvador (quoted above, page 207, note 2) p. 39, the value of the balsam exported in 1876 from that country is stated to have been 78,189 dollars. The value of tobacco amounted to 69,717 dollars, that of coffee to 1⅓ millions of dollars, indigo to 2¼ millions.
=Uses=—Occasionally prescribed in the form of ointment as a stimulating application to old sores, sometimes internally for the relief of asthma and chronic cough. It is said to be also employed for scenting soap.
=Adulteration=—We have before us a sample of an adulterated balsam, which, we are told, is largely prepared at Bremen. It is less aromatic, less rich in acids, and contains usually much less than 38 per cent. of resin separable, as above stated, by means of bisulphide of carbon. At first sight however the adulterated drug is not so easily recognized.
Other sorts of Balsam of Peru.
The value anciently set upon balsam for religions and medicinal uses, led to its being extracted from the pods and also from trees no longer employed for the purpose; and many of the products so obtained have attracted the attention of pharmacologists.[810] Parkinson writing in 1640 observes that—“there have been divers other sorts of liquours, called Balsamum for their excellent vertues, brought out of the West Indies, every one of which for a time after their first bringing was of great account with all men and bought at great prices, but as greater store was brought, so did the prices diminish and the use decay ...”
In Salvador, the name Balsamo blanco (White Balsam) is applied to the soft resin contained in the large ducts of the legume of Myroxylon Pereiræ. This, when pressed out, forms a golden yellow, semi-fluid, granular, crystalline mass, hardening by age, having a rather unpleasant odour suggestive of melilot. Stenhouse (1850) obtained from it the neutral resin Myroxocarpin, C₂₄H₃₄O₃, in thin colourless prisms, an inch or more in length. We have succeeded in extracting it directly from the pods. This White Balsam, which is distinctly mentioned in the letter of Palacio in 1576 (see p. 206), is a scarce and valuable article, never prepared for the market. A large jar of it was sent to Pereira in 1850;[811] Guzman[812] and Wyss state that it is known in the country as “Balsamito,” or “Balsamo catolico or Virgin Balsam.”
[810] Guibourt, Hist. des Drog. iii. (1850) 440.
[811] Pharm. Journ. x. (1851) 286.
[812] In the Catalogue alluded to, page 207, note 2.
A fragrant balsamic resin is collected, though in but very small quantity, from Myroxylon peruiferum Linn. f., a noble tree of New Granada, Ecuador, Peru, Bolivia, and Brazil. A fine sample of this substance, accompanied by herbarium and other specimens, was presented to one of us (H.) by Mr. J. Correa de Méllo of Campinas (Brazil); it is a resin having a general resemblance to Balsam of Tolu, but of somewhat deeper and redder tint, and greater hardness. Pressed between two slips of warmed glass, it does not exhibit any crystals.
In a treatise on Brazil written by a Portuguese friar about 1570-1600,[813] mention is made of the “Cabueriba” (Cabure-iba), from which a much-esteemed balsam was obtained by making incisions in the stem, and absorbing the exudation with cotton wool, somewhat in the same way as Balsam of Peru is now collected in Salvador. This tree is Myrocarpus frondosus Allem., now called Cabriuva preta. The genus is closely allied to Myroxylon.
Another fragrant oleo-resin, which has doubtless been confounded with that of a Myroxylon, is obtained in Central America from Liquidambar styraciflua L., either by incision or by boiling the bark.
SEMEN BONDUCELLÆ
Semen Guilandinæ; Bonduc Seeds, Grey Nicker Seeds or Nuts; F. Graines de Bonduc ou du Cniquier, Pois Quéniques, Pois Guénic.
=Botanical Origin=—Cæsalpinia Bonducella Roxb. (Guilandina Bonducella L.), a prickly, pubescent, climbing shrub[814] of wide distribution, occurring in Tropical Asia, Africa and America, especially near the sea. The compressed, ovate, spiny legume is 2 to 3 inches long, and contains one or two, occasionally three or four, hard, grey, globular seeds.
The plant is often confounded with C. Bonduc Roxb., a nearly allied but much rarer species, distinguished by being nearly glabrous, having leaflets very unequal at the base, no stipules, erect bracts, and yellow seeds.
=History=—“Pūti-Karanja” stinking Karanja, in Susruta (I.223, 1) is the plant under notice. The word Bunduk, occurring in the writings of the Arabian and Persian physicians, also in Constantinus Africanus, mostly signifies hazel-nut.[815] One of these authors, Ibn Baytar,[816] who flourished in the 13th century, further distinguished a drug called Bunduk Hindi (Indian hazel-nut), giving a description which indicates it plainly as the seed under notice. Both Bunduk and Bunduk Hindi are enumerated in the list of drugs of Noureddeen Mohammed Abdullah Shirāzy,[817] physician to the Mogul emperor Shah Jehan, A.D. 1628-1661.
The pods of C. Bonducella were figured by Clusius in 1605, under the name of Lobus echinodes, and the plant both by Rheede[818] and Rumphius. Piso and Marcgraf (1648) noticed it in Brazil and gave some account of it with a bad woodcut, under the designation of Inimbóy (now Inimboja), or in Portuguese Silva do Praya.
[813] Purchas, His Pilgrimes, iv. (1625) 1308.
[814] Fig. in Bentley and Trimem, Med. Plants, part 24 (1877).
[815] The word also means a little ball or a round stone. Bunduk Hindi is frequently used by Arabic authors to denote also Areca nut.
[816] Sontheimer’s translation, i. 177.
[817] Ulfaz Udwiyeh, translated by Gladwin, 1793. No. 543. 551.
[818] Hort. Malab. ii. (1679) tab. 22, sub nom. Caretti.
In recent times, Bonduc seeds have been employed on account of their tonic and antiperiodic properties by numerous European practitioners in the East, and have been included in the Pharmacopœia of India, 1868.
=Description=—The seeds are somewhat globular or ovoid, a little compressed, ⁴/₁₀ to ⁸/₁₀ of an inch in diameter and weighing 20 to 40 grains. They are of a bluish or greenish grey tint, smooth, yet marked by slightly elevated horizontal lines of a darker hue. The umbilicus is surrounded by a small, dark brown, semilunar blotch opposite the micropyle. The hard shell is from ¹/₂₅ to ²/₂₅ of an inch thick, and contains a white kernel; representing from 40 to 50 per cent. of the weight of the seed. It separates easily from the shell, and consists of the two cotyledons and a stout radicle. When a seed is soaked for some hours in cold water, a very thin layer can be peeled from the surface of the testa. The kernel is bitter, but with the taste that is common to most seeds of the family Leguminosæ.
=Microscopic Structure=—The outer layer of the testa, the epidermis above alluded to, is composed of two zones of perpendicular, closely packed cells, the outer measuring about 130 mkm., the inner 100 mkm. in length and only 5 to 7 mkm. in diameter. The walls of these cylindrical cells are thickened by secondary deposits, which in transverse section show usually four or more channels running down nearly perpendicularly through the whole cell.
The spongy parenchyme, which is covered by this very distinct outer layer, is made up of irregular, ovate, subglobular or somewhat elongated cells with large spaces between them, loaded with brown masses of tannic matter, assuming a blackish hue when touched with perchloride of iron. The thick walls of these cells frequently exhibit, chiefly in the inner layers, undulated outlines. The tissue of the cotyledons is composed of very large cells, swelling considerably in water, and containing some mucilage (as may be ascertained when thin slices are examined in oil), small starch granules, fatty oil, and a little albuminous matter.
=Chemical Composition=—According to the medical reports alluded to in the Pharmacopœia of India (1868), Bonduc seeds, and still more the root of the plant, act as a powerful antiperiodic and tonic.
The active principle has not yet been adequately examined. It may perhaps occur in larger proportion in the bark of the root, which is said to be more efficacious than the seeds in the treatment of intermittent fever.[819]
In order to ascertain the chemical nature of the principle of the seeds, one ounce of the kernels[820] was powdered and exhausted with slightly acidulated alcohol. The solution after the evaporation of the alcohol was made alkaline with caustic potash, which did not produce a precipitate. Ether now shaken with the liquid, completely removed the bitter matter, and yielded it in the form of an amorphous white powder, devoid of alkaline properties. It is sparingly soluble in water, but readily in alcohol, forming intensely bitter solutions; an aqueous solution is not precipitated by tannic acid. It produces a yellowish or brownish solution with concentrated sulphuric acid, which acquires subsequently a violent hue. Nitric acid is without manifest influence. From these experiments, we may infer that the active principle of the Bonduc seed is a bitter substance not possessing basic properties.
[819] Waring, Bazaar Medicines, Travancore, 1860. 18.
[820] Kindly furnished us by Dr. Waring.
=Uses=—The powdered kernels either per se, or mixed with black pepper (Pulvis Bonducellæ compositus Ph. Ind.), are employed in India against intermittent fevers and as a general tonic.
The fatty oil of the seeds is sometimes extracted and used in India; it was shown at the Madras Exhibitions of 1855 and 1857.
LIGNUM HÆMATOXYLI
Lignum Campechianum v. Campescanum; Logwood, Peachwood; F. Bois de Campèche, Bois d’Inde; G. Campecheholz, Blauholz.
=Botanical Origin=—Hæmatoxylon campechianum L., a spreading tree[821] of moderate size, seldom exceeding 40 feet in height, native of the bay of Campeachy, Honduras and other parts of Central America. It was introduced into Jamaica by Dr. Barham[822] in 1715, and is now completely naturalized in that and other of the West Indian Islands.
=History=—Hernan Cortes in his letter to the Emperor Charles V., giving an account of his expedition to Honduras in 1525,[823] refers to the Indian towns of Xiculango and Tabasco as carrying on a trade in cacao, cotton cloth, and colours for dyeing,—in which last phrase there may be an allusion to logwood. We have sought for some more definite notice of the wood in the Historia de las Indias of Oviedo,[824] the first chronicler of America, but without much success.
Yet the wood must have been introduced into England in the latter half of the 16th century, for, in 1581, an Act of Parliament[825] was passed, abolishing its use and ordering that any found should be forfeited and burned. In this Act the obnoxious dye is described as “a certain kind of ware or stuff called Logwood alias Blockwood ... of late years ... brought into this realm of England.” The object of this measure was to protect the public against the bad work of the dyers, who, it seems, were unable at that period to obtain durable colours by the use of logwood. Eighty years later the art of dyeing had so far improved that logwood was again permitted,[826] the colours produced by it being declared as lasting and serviceable as those made by any other sort of dyewood whatsoever.
The wood is mentioned by De Laet (1633) as deriving its name from the town of Campeachy, whence, says he, it is brought in great plenty to Europe.[827]
[821] Fig. in Bentley and Trimen, Med. Plants, part 5 (1876).
[822] Hortus Americanus, Kingston, Jamaica, 1794. 91.
[823] Fifth Letter of Hernan Cortes to the Emperor Charles V., Lond. (Hakluyt Society) 1868. 43.
[824] The first edition bears date 1535. We have used the modern one of Madrid, 1851-55, 4to., and may refer in particular to tom. i. lib. ix. c. 15, iii. lib. xxxi. c. 8 and c. 11.—See Appendix: Fernandez.
[825] 23 Eliz. c. 9.
[826] 13-14 Car. ii. c. 11. sect. 26 (A.D. 1662), by which the Act of Elizabeth was repealed.
[827] Novus Orbis, 1633. 274 and 265.
As a medicine, logwood was not employed until shortly before the year 1746, when it was introduced into the London Pharmacopœia under the name of Lignum tinctile Campechense.
=Description=—The tree is fit to be felled when about ten years old; the dark bark and the yellowish sapwood are chipped off, the stems cut into logs about three feet long, and the red heartwood alone exported. By exposure to air and moisture, the wood acquires externally a blackish-red colour; internally it remains brownish red. It splits well, although of a rather dense and tough texture.
The transverse section of a piece of logwood exhibits to the naked eye a series of very narrow concentric zones, formed by comparatively large pores, and of small parenchymatous circles separated by the larger and darker rings of the proper woody tissue. The numerous medullary rays are visible only by means of a lens. The wood has a pleasant odour.
For use in pharmacy, logwood is always purchased in the form of chips, which are produced by the aid of powerful machinery. The chips have a feeble, seaweed-like odour, and a slightly sweet, astringent taste, better perceived in a watery decoction than by chewing the dry wood, which however quickly imparts to the saliva its brilliant colour.
=Microscopic Structure=—Under a high magnifying power, the concentric zones are seen to run not quite regularly round the centre, but in a somewhat undulating manner, because they do not correspond, as in our indigenous woods, to regular periods of annual growth. The vascular bundles contain only a few vessels, and are transversely united by small lighter parenchymatous bands. The latter are made up of large, cubic, elongated or polygonal cells, each loaded with a crystal of oxalate of calcium. The large punctuated vessels having frequently 150 mkm. diameter, are surrounded by this woody parenchyme, while the prevailing tissue of the wood is composed of densely packed prosenchyme, consisting of long cylindrical cells (libriform) with thick, dark red-brown walls having small pores.
The medullary rays are of the usual structural character, running transversely in one to three straight rows; in a longitudinal section, the single rays show from 4 to 40 rows succeeding each other perpendicularly. No regular arrangement of the rays is obvious in a longitudinal section made in a tangential direction. The colouring matter is chiefly contained in the walls of the ligneous tissue and the vessels, and sometimes occurs in crystals of a greenish hue within the latter, or in clefts of the wood.
=Chemical Composition=—Logwood was submitted to analysis by Chevreul as early as the year 1810,[828] since which period all contributions to a knowledge of the drug refer exclusively to its colouring principle Hæmatoxylin, which Chevreul obtained in a crystallized state and called Hématine. The very interesting properties of this substance have been chiefly examined by Erdmann (1842) and by O. Hesse (1858-59).
[828] Annals de Chimie, lxxxi. (1812) 128.
Erdmann obtained from logwood 9 to 12 per cent. of crystallized hæmatoxylin, which he showed to have the formula C₁₆H₁₄O₆. In a pure state it is colourless, crystallizing with 1 or with 3 equivalents of water, and is readily soluble in hot water or in alcohol, but sparingly in cold water or in ether. It has a persistent sweet taste like liquorice. The crystals of hæmatoxylin acquire a red colour by the action of sunlight, as likewise their aqueous solution. They are decomposed by ozone but not by pure and dry oxygen. In presence of alkalis, hæmatoxylin exposed to the air quickly yields dark purplish violet solutions, which soon acquire a yellowish or dingy brownish colour; hence in analytical chemistry hæmatoxylin is used as a test for alkalis.
By the combined action of ammonia and oxygen, dark violet crystalline scales of Hæmateïn, C₁₆H₁₄O₆ + 3 OH₂, are produced.[829] They show a fine green hue, which is also very commonly observable on the surface of the logwood chips of commerce. Hæmateïn may again be transformed into hæmatoxylin by means of hydrogen or of sulphurous acid.
Hæmatoxylin separates protoxide of copper from an alkaline solution of the tartrate, and deviates the ray of polarized light to the right hand. It is not decomposed by concentrated hydrochloric acid; by melting hæmatoxylin with potash, pyrogallol (pyrogallic acid, C₆H₆O₃) is obtained. Alum and the salts of lead throw down precipitates from solutions of hæmatoxylin, the latter being of a bluish-black colour. Logwood affords upon incineration 3·3 per cent. of ash.
The colouring matter being abundantly soluble in boiling water, an Extract of Logwood is also prepared on a large scale. It occurs in commerce in the form of a blackish brittle mass, taking the form of the wooden chest into which it is put while soft. The extract shares the chemical properties of hæmatoxylin and hæmateïn: whether it also contains gum requires investigation.
=Production and Commerce=—The felling and shipping of logwood in Central America have been described by Morelet,[830] who states that in the woods of Tabasco and Yucatan the trade is carried on in the most irrational and reckless manner. By advancing money to the natives, or by furnishing them with spirits, arms, or tools, the proprietors of the woods engage them to fell a number of trees in proportion to their debts. This is done in the dry season, the rainy period being taken for the shipment of the logs, which are conveyed chiefly to the island of Carmen in the Laguna de Terminos in South-western Yucatan, and to Frontera on the mouths of the Tabasco river, at which places European ships receive cargoes of the wood.
In 1877 the export of Laguna de Terminos amounted to 528,605 quintals (one quintal = 46 kilogrammes), that from Port-au-Prince, Hayti, in 1872, nearly to 90,000 tons.
Four sorts of logwood are found in the London market, namely Campeachy, quoted[831] at £8 10_s._ to £9 10_s._ per ton; Honduras, £6 10_s._ to £6 15_s._; St. Domingo, £5 15_s._ to £6; Jamaica, £5 2_s._ 6_d._ to £5 10_s._ The imports into the United Kingdom were valued in 1872 at £233,035. The quantities imported during that and the previous three years were as follows:—
1869 1870 1871 1872 50,458 tons. 62,187 tons. 39,346 tons. 46,039 tons.
[829] Benedikt, in 1875, assigned them the formula C₄₈H₃₉O₁₈N + 9 OH₂.
[830] Voyage dans l’Amérique centrale, l’île de Cuba et le Yucatan, Paris, 1857.
[831] Public Ledger, 28 Feb. 1874.
In 1876 the import was 64,215 tons, valued at £415,857. The largest quantity is supplied by the British West India Islands. Hamburg also imports annually about 20,000 tons of logwood.
=Uses=—Logwood in the form of decoction is occasionally administered in chronic diarrhœa, and especially in the diarrhœa of children. Cases have occurred in which its use has been followed by phlebitis. Its employment in the art of dyeing is far more important.
=Adulteration=—The woods of several species of Cæsalpinia imported under the name of Brazil Wood and used for dyeing red, bear an external resemblance to logwood, with which it is said they are sometimes mixed in the form of chips. They contain a crystallizable colouring principle called Brasilin, C₂₂H₂₀O₇, or, according to Liebermann and Burg (1876), C₁₆H₁₄O₅, which affords with alkalis red and not bluish or purplish solutions, and yields trinitrophenol, C₆H₂(NO₂) 3OH (picric acid), when boiled with nitric acid, while hæmatoxylin yields oxalic acid only. The best source for brasilin is the wood of Cæsalpinia Sappan L., a tree of the East Indies, well known as Bakam, Brazil Wood, Lignum Brasile, Verzino of the Italians, an important object of commerce during the middle ages.[832]
FOLIA SENNÆ
Senna Leaves; F. Feuilles de Séné; G. Sennesblätter.
=Botanical Origin=—The Senna Leaves of commerce are afforded by two species of Cassia[833] belonging to that section of the genus which is distinguished by having leaves without glands, axillary racemes elongating as inflorescence advances, membranaceous bracts which in the young raceme conceal the flower buds but drop off during flowering, and a short, broad, flat legume.
The senna plants are low perennial bushy shrubs, 2 to 4 feet high, having pari-pinnate leaves with leaflets unequal at the base, and yellow flowers. The pods contain 6 or more seeds in each, suspended on alternate valves by long capillary funicles. These run towards the pointed end of the seed, but are curved at their attachment to the hilum just below. The seeds are compressed and of an obovate-cuneate or oblong form, beaked at the narrower end.[834]
The species in question are the following:—
1. Cassia acutifolia Delile[835]—a shrub about 2 feet high, with pale subterate or obtusely angled, erect or ascending branches, occasionally slightly zigzag above, glabrous at least below. Leaves usually 4-5-jugate; leaflets oval or lanceolate, acute, mucronate, usually more or less distinctly puberulous or at length glabrous, pale or subglaucous at least beneath, subsessile. Stipules subulate, spreading or reflexed, 1-2 lines long. Racemes axilliary, erect, rather laxly many-flowered, usually considerably exceeding the subtending leaf. Bracts membranous, ovate or obovate, caducous. Pedicels at length 2-3 lines. Sepals obtuse, membranous. Two of the anterior anthers much exceeding the rest of the fertile stamens. Legume flat, very broadly oblong, but slightly curved upwards, obliquely stipitate, broadly rounded at the extremity with a minute or obsolete mucro indicating the position of the style on the upper edge; 1½-2¼ inches long, ¾-1 inch broad; valves chartaceous, obsoletely or thinly puberulous, faintly transverse-veined, unappendaged. Seeds obovate-cuneate, compressed; cotyledons plane, extending the large diameter of the seed in transverse section.[836]
[832] See Yule, Marco Polo, ii. (1874). 369.
[833] Some writers have removed these plants from Cassia to a separate genus named Senna, but such subdivision is repudiated by the principal botanists. The intricate synonymy of the senna plants has been well worked out by J. B. Batka in his memoir entitled Monographie der Cassien-Gruppe Senna (Prag, 1866), of which we have made free use. We have also had the advantage of the recent Revision of the Genus Cassia by Bentham (Linn. Trans., xxvii. 1871. 503) and of the labours of Oliver on the same subject in his Flora of Tropical Africa, ii. (1871) 268-282.
[834] On the structure of the seed, see Batka, Pharm. Journ. ix. (1850) 30.
[835] Synonyms—C. Senna β. Linn.; C. lanceolata Nectoux; C. lenitiva Bisch.; Senna acutifolia Batka.
[836] We borrow the above description from Prof. Oliver.
The plant is a native of many districts of Nubia (as Sukkot, Mahas, Dongola, Berber), Kordofan and Sennaar; grows also in Timbuktu and Sokoto, and is the source of Alexandrian Senna.
2. C. angustifolia Vahl[837]—This species is closely related to the preceding, the general description of which is applicable to it with the following exceptions. In the present plant the leaflets, which are usually 5-8-jugate, are narrower, being oval-lanceolate, tapering from the middle towards the apex; they are larger, being from one to nearly 2 inches long, and are either quite glabrous or furnished with a very scanty pubescence. The legume is narrower (7-8 lines broad), with the base of the style distinctly prominent on its upper edge.
The plant abounds in Yemen and Hadramaut in Southern Arabia; it is also found on the Somali coast, in Sind and the Punjab. In some parts of India it is now cultivated for medicinal use.
The uncultivated plant of Arabia supplies the so-called Bombay Senna of commerce, the true Senna Mekki of the East. The cultivated and more luxuriant plant, raised originally from Arabian seeds, furnishes the Tinnevelly Senna of the drug market.
=History=—According to the elaborate researches of Carl Martius,[838] a knowledge of senna cannot be traced back earlier than the time of the Elder Serapion, who flourished in the 9th or 1Oth century; and it is in fact to the Arabian physicians that the introduction of the drug to Western Europe is due. Isaac Judæus,[839] who wrote probably about A.D. 850-900 and who was a native of Egypt, mentions senna, the best kind of which he says is that brought from Mecca.
Senna (as Ssinen or Ssenen) is enumerated among the commodities liable to duty at Acre in Palestine at the close of the 12th century.[840] In France in 1542, a pound of senna was valued in an official tariff[841] at 15 sols, the same price as pepper or ginger.
The Arabian and the mediæval physicians of Europe used both the pods and leaves, preferring however the former. The pods (Folliculi Sennæ) are still employed in some countries.
[837] Synonyms—C. lanceolata Roxb.; C. elongata Lem. Lis.; Senna officinalis Roxb.; S. angustifolia Batka.
[838] Versuch einer Monographie der Sennesblätter, Leipz. 1867.
[839] Opera Omnia, Lugd. 1515, lib. 2. Practices, c. 39.
[840] Recueil des Historiens des Croisades, Lois, ii. (1843) 177.
[841] Fontanon, Edicts et Ordonnances des Roys de France, éd. 2, ii. (1585) 349.
Cassia obovata Coll.[842] was the species first known to botanists, and it was even cultivated in Italy for medicinal use during the first half of the 16th century. Hence the term Italian Senna used by Gerarde and others. In the records of the “Cinque savii alla mercanzia” at Venice we found an order bearing date 1526 to the effect that Senna leaves of Tuscany were inadmissible; the same was applied in 1676 to the drug from Tripoli in Barbaria, that from Cairo being exclusively permitted.
=Production=—According to Nectoux,[843] whose observations relate to Nubia at the close of the last century, the peasants make two senna harvests annually, the first and more abundant being at the termination of the rains,—that is in September; while the other, which in dry seasons is almost nil, takes place in April.
The gathering consists in simply cutting down the shrubs, and exposing them on the rocks to the burning sun till completely dry. The drug is then packed in bags made of palm leaves holding about a quintal each, and conveyed by camels to Es-souan and Darao, whence it is transported by water to Cairo. By many travellers it is stated that Senna jebeli, i.e. mountain senna (C. acutifolia), finds its way to the ports of Massowhah and Suakin, and thence to Cairo and Alexandria.
Cassia obovata, which is called by the Arabs Senna baladi, i.e. indigenous or wild senna, grows in the fields of durra (Sorghum) at Karnak and Luxor, and in the time of Nectoux was held in such small esteem that it fetched but a quarter the price of the Senna jebeli brought by the caravans of Nubia and the Bisharrin Arabs. It is not now collected.
=Description=—Three kinds of senna are distinguished in English commerce:—
1. Alexandrian Senna—This is furnished by Cassia acutifolia and is imported in large bales. It used formerly always to arrive in a very mixed and dirty state, containing, in addition to leaflets of senna, a variable proportion of leafstalks and broken twigs, pods and flowers; besides which there was almost invariably an accompaniment of the leaves, flowers and fruits of Solenostemma Argel Hayne (p. 220), not to mention seeds, stones, dust and heterogeneous rubbish. Such a drug required sifting, fanning and picking, by which most of these impurities could be separated, leaving only the senna contaminated with leaves of argel. But Alexandrian Senna has of late been shipped of much better quality. Some we have recently seen (1872) was, as taken from the original package, wholly composed of leaflets of C. acutifolia in a well-preserved condition; and even the lower qualities of senna are never now contaminated with argel to the extent that was usual a few years ago.
[842] It is a glaucous shrub with obovate leaflets, broadly rounded and mucronulate, reniform legume terminated by persistent style, and marked along the middle of each valve by a series of crest-shaped ridges corresponding to the seeds. It is more widely distributed in the Nile region than the other species, and is also found in Sindh and Gujerat and (naturalized) in the West Indies. Its leaflets (also pods) may occasionally be picked out of Alexandrian Senna.
[843] Voyage dans la Haute Egypte ... avec des observations sur les diverses espèces de Séné qui sont répandues dans le commerce, Paris, 1808. fol.
The leaflets, the general form of which has already been described (p. 216), are ¾ to 1¼ inches long, rather stiff and brittle, generally a little incurled at the edges, conspicuously veined, the midrib being often brown. They are covered with a very short and fine pubescence which is most dense on the midrib. The leaves have a peculiar opaque, light yellowish green hue, a somewhat agreeable tea-like odour, and a mucilaginous, not very marked taste, which however is sickly and nauseous in a watery infusion.
2. Arabian Moka, Bombay or East Indian Senna—This drug is derived from Cassia angustifolia, and is produced in Southern Arabia. It is shipped from Moka, Aden and other Red Sea ports to Bombay, and thence reaches Europe.
Arabian senna is usually collected and dried without care, and is mostly an inferior commodity, fetching in London sometimes as low a price as ½_d._ to ¼_d._ per lb. Yet so far as we have observed, it is never adulterated, but consists wholly of senna leaflets, often brown and decayed, mixed with flowers, pods, and stalks. The leaflets have the form already described (p. 217); short adpressed hairs are often visible on their under surface.
3. Tinnevelly Senna—Derived from the same species as the last, but from the plant cultivated in India, and in a state of far greater luxuriance than it exhibits in the drier regions of Arabia where it grows wild. It is a very superior and carefully collected drug, consisting wholly of the leaflets. These are lanceolate, 1 to 2 inches in length, of a yellowish green on the upper side, of a duller tint on the under, glabrous or thinly pubescent on the under side with short adpressed hairs. The leaflets are less rigid in texture than those of Alexandrian senna, and have a tea-like, rather fragrant smell, with but little taste.
Tinnevelly senna has of late fallen off in size, and some importations in 1873 were not distinguishable from Arabian senna, except from having been more carefully prepared. The drug is generally shipped from Tuticorin in the extreme south of India.
=Chemical Composition=—The analysis of senna with a view to the isolation of its active principle has engaged the attention of numerous chemists, but as yet the results of their labours are not quite satisfactory.
Ludwig (1864) treated an alcoholic extract of senna with charcoal, and obtained from the latter by means of boiling alcohol two bitter principles, Sennacrol, soluble in ether, and Sennapicrin, not dissolved by ether.
Dragendorff and Kubly (1866) have shown the active substance of senna to be a colloid body, easily soluble in water but not in strong alcohol. When a syrupy aqueous extract of senna is mixed with an equal volume of alcohol, and the mucilage thus thrown down has been removed, the addition of a further quantity of alcohol occasions the fall of a dark brown, almost tasteless, easily alterable substance, which is indued with purgative properties. It was further shown that this precipitate was a mixture of calcium and magnesium salts of phosphoric acid and a peculiar acid. The last named, separated by hydrochloric acid, has been called Cathartic Acid; it is a black substance which in the mouth is at first insipid, but afterwards tastes acid and somewhat astringent. In water or strong alcohol it is almost insoluble, and entirely so in ether or chloroform; but it dissolves in warm dilute alcohol. From this solution it is precipitable by many acids, but not by tannic.
Groves[844] in 1868, unaware of the researches of Dragendorff and Kubly, arrived at similar results as these chemists, and proved conclusively that a cathartate of ammonia possesses in a concentrated form the purgative activity of the original drug.
The exactness of the chief facts relative to the solubility in weak alcohol of the active principle of senna set forth by the said chemists, was also remarkably supported by the long practical experience of T. and H. Smith of Edinburgh.[845]
When cathartic acid is boiled with alcohol and hydrochloric acid, it is resolved into sugar and Cathartogenic Acid.
The alcoholic solution from which the cathartates have been separated contains a yellow colouring matter which was called Chrysoretin by Bley and Diesel (1849), but identified as Chrysophan[846] by Martius, Batka and others. Dragendorff and Kubly regard the identity of the two substances as doubtful.
The same alcoholic solution which contains the yellow colouring matter just described, also holds dissolved a sugar which has been named Catharto-mannite. It forms warty crystals, is not susceptible of alcoholic fermentation, and does not reduce alkaline cupric tartrate. The formula assigned to it is C₄₂H₄₄O₃₈.
Senna contains tartaric and oxalic acids with traces of malic acid. The large amount of ash, 9 to 12 per cent., consisting of earthy and alkaline carbonates, also indicates the presence of a considerable quantity of organic acids.
=Commerce=—Alexandrian Senna, the produce of Nubia and the regions further south, was formerly a monopoly of the Egyptian Government, the enjoyment of which was granted to individuals in return for a stipulated payment: hence it was known in continental trade as Séné de la palte, while the depots were termed paltes and those who farmed the monopoly paltiers.[847] All this has long been abolished, and the trade is now free, the drug being shipped from Alexandria.
Arabian senna is brought into commerce by way of Bombay. The quantity of senna imported thither from the Red Sea and Aden in the year 1871-72 was 4,195 cwt., and the quantity exported during the same period, 2,180 cwt.[848]
=Uses=—Senna leaves are extensively employed in medicine as a purgative.
=Adulteration=—The principal contamination to which senna is at present liable arises from the presence of the leaves of Solenostemma Argel Hayne, a plant of the order Asclepiadeæ, 2 to 3 feet high, growing in the arid valleys of Nubia. Whether these leaves are used for the direct purpose of adulteration, or under the notion of improving the drug, or in virtue of some custom or prejudice, is not very evident. It is certain however that druggists have been found who preferred senna that contained a good percentage of argel.
[844] Pharm. Journ. x. (1869) 196.
[845] Ibid. 315.
[846] See Art. Radix Rhei.
[847] From Italian appaltare, to let or farm.
[848] Statement of the Trade and Navigation of the Presidency of Bombay for 1871-72, pt. ii. 21. 98.
Nectoux, to whom we owe the first exact account of the argel or hárgel plant,[849] describes it as never gathered with the senna by accident or carelessness, but always separately. In fact he saw, both at Esneh and Phile, the original bales of argel as well as those of senna: and at Boulak near Cairo, at the beginning of the present century, the argel used to be regularly mixed with senna in the proportion of one to four.
The leaves of argel after a little practice are very easily recognized; but their complete separation from senna by hand-picking is a tedious operation. They are lanceolate, equal at the base, of the same size as senna leaflets but often larger, of a pallid, opaque, greyish-green, rigid, thick, rather crumpled, wrinkled and pubescent, not distinctly veined. They have an unmistakeably bitter taste. The small, white, star-like flowers, or more often the flower buds, in dense corymbs are found in plenty in the bales of Alexandrian senna. The slender, pear-shaped follicles, when mature 1½ inches long, with comose seeds are less frequent. It has been shown by Christison[850] that argel leaves administered per se have but a feeble purgative action, though they occasion griping. It is plain therefore that their admixture with senna should be deprecated.
The leaves or leaflets of several other plants were formerly mixed occasionally with senna, as those of the poisonous Coriaria myrtifolia L., a Mediterranean shrub, of Colutea arborescens L., a native of Central and Southern Europe, and of the Egyptian Tephrosia Apollinea Delile. We have never met with any of them.[851]
FRUCTUS CASSIÆ FISTULÆ
Cassia Fistula; Purging Cassia; F. Casse Canefice, Fruit du Caneficer; G. Röhrencassie.
=Botanical Origin=—Cassia Fistula L. (Cathartocarpus Fistula Pers., Bactyrilobium Fistula Willd.) a tree indigenous to India, ascending to 4000 feet in the outer Himalaya, but now cultivated or subspontaneous in Egypt, Tropical Africa,[852] the West Indies and Brazil. It is from 20 to 30 feet high (in Jamaica even 50 feet) and bears long pendulous racemes of beautiful fragrant, yellow flowers. Some botanists have established for this tree and its near allies a separate genus, on account of its elongated, cylindrical indehiscent legume, but by most it is retained in the genus Cassia.
[849] Op. cit. (See p. 218).
[850] Dispensatory, ed. 2. 1848. 850.
[851] The reader will find figures of these leaves contrasted with Senna in Pereira’s Elem. of Mat. Med. ii. part ii (1853) 1866.
[852] Schweinfurth found it in 6° N. lat. and 28-29° E. long., in the country of the Dor, where the tree may also be indigenous.
=History=—The name Casia or Cassia was originally applied exclusively to a bark related to cinnamon which, when rolled into a tube or pipe, was distinguished in Greek by the word σῦριγζ, and in Latin by that of fistula. Thus Scribonius Largus,[853] a physician of Rome during the reigns of Tiberius and Claudius, with the latter of whom he is said to have visited Britain, A.D. 43, uses the expression “Casiæ rufæ fistularum” in the receipt for a collyrium. Galen[854] describing the different varieties of cassia, mentions that called Gizi[855] (γίζεις) as being quite like cinnamon or even better; and also names a well-known cheaper sort, having a strong taste and odour which is called fistula, because it is rolled up like a tube.
Oribasius, physician to the Emperor Julian in the latter half of the 4th and beginning of the 5th century, describes Cassia fistula as a bark of which there are several varieties, having pungent and astringent properties (“omnes cassiæ fistulæ vires habent acriter exalfacientes et stringentes”), and sometimes used in the place of cinnamon.[856]
It is doubtless the same drug which is spoken of by Alexander Trallianus[857] as Κασίας σῦριγζ (casia fistula) in connexion with costus, pepper and other aromatics; and named by other Greek writers as Κασία συριγγώδης (casia fistularis). Alexander still more distinctly calls it also Κασία αἰγυπτία.[858]
The tree under examination and its fruit were exactly described in the beginning of the 13th century by Abul Abbâs Annâbatî of Sevilla;[859] the fruit, the Cassia Fistula of modern medicine, is noticed by Joannes Actuarius, who flourished at Constantinople towards the close of the 13th century; and as he describes it with particular minuteness,[860] it is evident that he did not consider it well known. The drug is also mentioned by several writers of the school of Salernum. The tree would appear to have found at an early period its way to America, if we are correct in referring to it the Cassia Fistula enumerated by Petrus Martyr among the valuable products of the New World.[861] The drug was a familiar remedy in England in the time of Turner, 1568.[862]
The tree was figured in 1553 by the celebrated traveller Belon who met with it in the gardens of Cairo, and in 1592 by Prosper Alpinus who also saw it in Egypt.
=Description=—The ovary of the flower is one-celled with numerous ovules, which as they advance towards maturity become separated by the growth of intervening septa. The ripe legume is cylindrical, dark chocolate-brown, 1½ to 2 feet long by ¾ to 1 inch in diameter, with a strong short woody stalk, and a blunt end suddenly contracted into a point. The fibro-vascular column of the stalk is divided into two broad parallel seams, the dorsal and ventral sutures, running down the whole length of the pod, The sutures are smooth, or slightly striated longitudinally; one of them is formed of two ligneous bundles coalescing by a narrow line. If the legume is curved, the ventral suture commonly occupies its inner or concave side. The valves of the pods are marked by slight transverse depressions (more evident in small specimens) corresponding to the internal divisions, and also by inconspicuous transverse veins.
[853] Compositiones Medicamentorum, cap. 4. sec. 36.
[854] De Antidot. i. c. 14.
[855] Noticed likewise among the commodities liable to duty at Alexandria in the 2nd century.—Vincent, Commerce of the Ancients, ii. 712.
[856] Physica Hildegardis, Argent. 1533. 227.
[857] Libri xii. J. Guinterio interprete, Basil., 1556. lib. vii. c. 8.
[858] Puschmann’s edition (quoted in the appendix) i. 435.
[859] Meyer, Geschichte der Botanik, iii. (1856). 226.
[860] “Quemadmodum si ventrem mollire fuerit animus, pruna, et præcipué Damascena adjicimus, atque quippiam feré nigræ nominatæ casiæ. Est autem fructus ejus fistulus et oblongus, nigrum intus humorem concretum gestans, qui haudquaquam una continuitate coaluit, sed ex intervallo tenuibus lignosisque membranulis dirimitur, habens ad speciei propagationem, grana quædam seminalia, siliquæ illi quæ nobis innotuit, adsimilia.”—Methodus Medendi, lib. v. c. 2.
[861] De nuper sub D. Carolo repertis insulis, Basil. 1521.
[862] Herball, part. 3. 20.
Each of the 25 to 100 seeds which a legume contains, is lodged in a cell formed by very thin woody dissepiments. The oval, flattish seed from ³/₁₀ to ⁴/₁₀ of an inch long, of a reddish-brown colour, contains a large embryo whose yellowish veined cotyledons cross diagonally, as seen on transverse section, the horny white albumen. One side is marked by a dark line (the raphe). A very slender funicle attaches the seed to the ventral suture.
In addition to the seeds, the cells contain a soft saccharine pulp which in the recent state fills them up, but in the imported pods appears only as a thin layer, spread over the septum, of a dark viscid substance of mawkish sweet taste. It is this pulp which is made use of in pharmacy.
=Microscopic Structure=—The bands above described running along the whole pod, are made up of strong fibro-vascular bundles mixed with sclerenchymatous tissue. The valves consist of parenchymatous cells, and the whole pod is coated with an epidermis exhibiting small tabular cells, which are filled with dark granules of tannic matter. A few stomata are also met with. The thin brittle septa of the pod are composed of long ligneous cells, enclosing here and there crystals of oxalate of calcium.
The pulp itself, examined under water, is seen to consist of loose cells, not forming a coherent tissue. They enclose chiefly granules of albuminoid matters and stellate crystals of oxalate of calcium. The cell-wall assumes, on addition of iodine, a blue hue if they have been previously washed by potash lye. The seeds are devoid of starch, but yield a copious amount of thick mucilage, which surrounds them like a halo if they are macerated in water.
=Chemical Composition=—No peculiar principle is known to exist either in the woody or the pulpy portion of cassia fistula. The pulp contains sugar in addition to the commonly occurring bodies noticed in the previous section.
=Uses=—The pulp separated from the woody part of the pods by crushing the latter, digesting them in hot water, and evaporating the strained liquor, is a mild laxative in common domestic use in the South of Europe,[863] but in England scarcely ever now administered except in the form of the well-known Lenitive Electuary (Confectio sennæ) of which it is an ingredient.
=Commerce=—Cassia fistula is shipped to England from the East and West Indies, but chiefly from the latter. The pulp per se has been occasionally imported, but it should never be employed when the legumes for preparing it can be obtained.
=Substitutes=—The pods of some other species of Cassia share the structure above described and have been sometimes imported.
[863] Thus there were imported into Leghorn in 1871, 103 tons of Cassia Fistula and Tamarinds.—Consular Reports, 1873, part i.
Those of C. grandis L. f. (C. brasiliana Lamarck), a tree of Central America and Brazil, are of much larger size, showing when broken transversely an elliptic outline, whose longer diameter exceeds an inch. The valves have very prominent sutures and transverse branching veins. The pulp is bitter and astringent.
The legumes of Cassia moschata H B K.,[864] a tree 30 to 40 feet high, growing in New Granada and known there as Cañafistola de purgar, bear a close resemblance to those of Cassia Fistula L., except that they are a little smaller and rather less regularly straight. They contain a sweetish astringent pulp of a bright brown hue. When crushed and exposed to the heat of a water-bath, they emit a pleasant odour like sandal-wood. The pulp is coloured dark blackish green by perchloride of iron.
TAMARINDI PULPA
Tamarindus, Fructus Tamarindi; Tamarinds; F. Tamarins; G. Tamarinden.
=Botanical Origin=—Tamarindus indica L.—The tamarind is a large handsome tree, growing to a height of 60 to 80 feet, and having abruptly pinnate leaves of 10 to 20 pairs of small oblong leaflets, constituting an abundant and umbrageous foliage. Its purplish flower buds and fragrant, red-veined, white blossoms, ultimately assuming a yellowish tinge, contribute to its beautiful aspect and cause it to be generally cultivated in tropical countries.
T. indica appears to be truly indigenous to Tropical Africa between 12° N. and 18° S. lat. It grows not only in the Upper Nile regions (Sennaar, Kordofan, Abyssinia), but also in some of the remotest districts visited by Speke, Grant, Kirk, and Stanley, and as far south as the Zambesi. According to F. von Müller,[865] it occurs in Tropical Australia.
It is found throughout India, and as it has Sanskrit names it may even be really wild in at least the southern parts of the peninsula. It grows in the Indian islands, and Crawfurd[866] has adduced reasons to show that it is probably a true native of Java. The mediæval Arabian authors describe it as growing in Yemen, India, and Nigritia.
The tamarind has been naturalized in Brazil, Ecuador and Mexico. Hernandez,[867] who resided in the latter country from 1571 to 1575, speaks of it as “nuper ... ad eas oras translata.” It abounds in the West Indies where it was also introduced together with ginger by the Spaniards at an early period. The tree found in these islands bears shorter and fewer-seeded pods than that of India, and hence was formerly regarded as a distinct species, Tamarindus occidentalis Gärtn.
[864] Hanbury in Linn. Trans. xxiv. 161. p. 26; Pharm. Journ. v. (1864) 348; Science Papers, p. 318.
[865] Exposition intercoloniale,—Notes sur la Végétation de l’Australie, Melb., 1866. 8.
[866] Dict. of Indian Islands, 1856. 425.
[867] Nova plantarum, animalium et mineralium historia, Romæ, 1651. 83.
=History=—The tamarind was unknown to the ancient Greeks and Romans; nor have we any evidence that the Egyptians were acquainted with it,[868] which is the more surprising considering that the tree appears indigenous to the Upper Nile countries, and that its fruit is held in the greatest esteem in those regions.[869]
The earliest mention of tamarind occurs in the ancient Sanskrit writings where it is spoken of under several names.[870] From the Hindus, it would seem that the fruit became known to the Arabians, who called it Tamare-hindi, i.e. Indian Date. Under this name it was mentioned by Isaac Judæus,[871] Avicenna,[872] and the Younger Mesue,[873] and also by Alhervi,[874] a Persian physician of the 10th century who describes it as black, of the flavour of a Damascene plum, and containing fibres and stones.
It was doubtless from the Arabians that a knowledge of the tamarind, as of so many other eastern drugs, passed during the middle ages into Europe through the famous school of Salernum. Oxyphœnica (Ὀζυϕοίνικα) and Dactyli acetosi are names under which we meet with it in the writings of Matthæus Platearius and Saladinus, the latter of whom, as well as other authors of the period, considered tamarinds as the fruit of a wild palm growing in India.
The abundance of tamarinds in Malabar, Coromandel, and Java was reported to Manuel, king of Portugal, in the letter of the apothecary Pyres[875] on the drugs of India, written in Cochin, January 27th, 1516. A correct description of the tree was given by Garcia de Orta about fifty years later.
=Preparation=—Tamarinds undergo a certain preparation before being brought into commerce.
In the West Indies, the tree matures its fruit in June, July and August, and the pods are gathered when fully ripe, which is known by the fragility of the outer shell. This latter, which easily breaks between the finger and thumb, is then removed, and the pods deprived of shelly fragments are placed in layers in a cask, and boiling syrup is poured over them till the cask is filled. When cool, the cask is closed and is then ready for sale. Sometimes layers of sugar are placed between the fruits previous to the hot syrup being added.[876]
East Indian tamarinds are also sometimes preserved with sugar, but usually they are exported without such addition, the outer shell being removed and the fruits being pressed together into a mass.
[868] Sir Gardner Wilkinson (Ancient Egyptians, i. 1841, 78) says that tamarind stones have been found in the tombs of Thebes; but on consulting Dr. Birch and the collections in the British Museum we have obtained no confirmation of the fact.
[869] Barth speaks of it as an invaluable gift of Providence: Reisen und Entdeckungen in Nord-und Centralafrica, Gotha, 1858. i. 614; iii. 334. 400; iv. 173.—The same says Rohlfs, Reisen durch Nordafrica, Gotha (1872) 23.
[870] Susrutas Ayurvedas, ed. Hessler, i. (1844) 141, iii. (1850) 171.
[871] Opera Omnia, Lugd. 1515, lib. ii. Practices, c. 41.
[872] Opera, Venet. 1564. ii. 339.
[873] Opera, Venet. 1561. 52.
[874] Fundamenta Pharmacologiæ, ed. Seligmann, Vindob. 1830, 49.
[875] Journ. de Soc. Pharm. Lusit. ii. (1838) 36.—See also Appendix.
[876] Lunan, Hortus Jamaicensis, ii. (1814) 224; Macfadyen, Flora of Jamaica, 1837. 335.
In the Upper Nile regions (Darfur, Kordofan, Sennaar) and in Arabia, the softer part of tamarinds is, for the sake of greater permanence and convenience of transport, kneaded into flattened round cakes, 4 to 8 inches in diameter and an inch or two thick, which are dried in the sun. They are of firm consistence and quite black, externally strewn with hair, sand, seeds and other impurities; they are largely consumed in Egypt and Central Africa, and sometimes find their way to the south of Europe as Egyptian Tamarinds.
=Description=—The fruit is an oblong, or linear-oblong, strictly compressed, curved or nearly straight, pendulous legume, of the thickness of the finger and 3 to 6 inches in length, supported by a woody stalk. It has a thin but hard and brittle outer shell or epicarp, which does not split into valves or exhibit any very evident sutures. Within the epicarp is a firm, juicy pulp, on the surface of which and starting from the stalk are strong woody ramifying nerves; one of these extends along the dorsal (or concave) edge, two others on either side of the ventral (or convex) edge, while between these two there are usually 2, 3, or 4 less regular and more slender nerves,—all running towards the apex and throwing out branching filaments. The brownish or reddish pulp has usually an acid taste, though there are also sweetish varieties.
The seeds, 4 to 12 in number, are each of them enclosed in a tough, membraneous cell (endocarp), surrounded by the pulp (sarcocarp). They are flattened and of irregular outline, being roundish, ovate, or obtusely four-sided, about ⁶/₁₀ of an inch long by ³/₁₀ thick, with the edge broadly keeled or more often slightly furrowed. The testa is of a rich brown, marked on the flat sides of the seed by a large scar or oreole, of rather duller polish than the surrounding portion which is somewhat radially striated. The seed is exalbuminous, with thick hard cotyledons, a short straight included radicle, and a plumule in which the pinnation of the leaves is easily perceptible.
Tamarinds are usually distinguished in trade as West Indian and East Indian, the former being preserved with sugar, the latter without.
1. West Indian Tamarinds, Brown or Red Tamarinds.—A bright reddish-brown, moist, saccharine mass consisting of the pulpy internal part of the fruit, usually unbroken, mixed with more or less of syrup. It has a very agreeable and refreshing taste, the natural acidity of the pulp being tempered by the sugar. It is this form of tamarinds that is usually found in the shops.
2. East Indian Tamarinds, Black Tamarinds.—These differ from the last described in that they are preserved without the use of sugar. They are found in the market in the form of a firm, clammy, black mass, consisting of the pulp mixed with the seeds, stringy fibres, and some remains of the outer shell. The pulp has a strong acid taste.
Notwithstanding the rather uninviting appearance of East Indian tamarinds, they afford a good pulp, which may be satisfactorily used in making the Confectio Sennæ of pharmacy. In fact, on the continent this sort of tamarind alone is employed for medicinal purposes.
=Microscopic Structure=—The soft part of tamarind consists of a tissue of thin-walled cells of considerable size, which is traversed by long fibro-vascular bundles. In the former a few very small starch granules are met with, and more numerous crystals, which are probably bitartrate of potassium.
=Chemical Composition=—Water extracts from unsweetened tamarinds, sugar together with acetic, tartaric and citric acids, the acids being combined for the most part with potash. The neutralized solution reduces alkaline cupric tartrate after a while without heat, and therefore probably contains grape sugar. On evaporation, cream of tartar and sugar crystallize out. The volatile acids of the fatty series, the presence of which in the pulp has been pointed out by Gorup-Besanez, have not been met with by other chemists. Tannin is absent as well as oxalic acid. We have ascertained that in East Indian tamarinds, citric acid is present in but small quantity. No peculiar principle to which the laxative action of tamarinds can be attributed is known.
The fruit-pulp diffused in water forms a thick, tremulous, somewhat glutinous and turbid liquid. It was examined as early as the year 1790 by Vauquelin under the name of “vegetable jelly,”—the first described among the pectic class of bodies.
The hard seeds have a testa which abounds in tannin, and after long boiling is easily separated, leaving the cotyledons soft. These latter have a bland mucilaginous taste, and are consumed in India as food during times of scarcity.
=Commerce=—Tamarinds are shipped in comparatively small quantities from several of the West Indian islands, and also from Guayaquil.
The export from the Bombay Presidency in the year 1871-72 was 6286 cwt., which quantity was shipped chiefly to the Persian Gulf, Sind, and ports of the Red Sea.[877] 128,144 centners were re-exported in 1877 from Trieste.
=Uses=—In medicine, tamarinds are considered to be a mild laxative; they are sometimes used to make a refrigerant drink in fever. In hot countries, especially the interior of Africa, they are regarded as of the highest value for the preparation of refreshing beverages. The Black Tamarinds are said to be used in the manufacture of tobacco.
[877] Statement of the Trade and Navigation of the Presidency of Bombay, 1871-72, pt. ii. 65.
BALSAMUM COPAIBA
Copaiba; Balsam of Copaiba or Copaiva, Balsam Capivi; F. Baume ou Oléo-résine de Copahu; G. Copaivabalsam.
=Botanical Origin=—The drug under notice is produced by trees belonging to the genus Copaifera, natives of the warmer countries of South America. Some are found in moist forests, others exclusively in dry and elevated situations. They vary in height and size, some being umbrageous forest trees, while others have only the dimension of shrubs; it is from the former alone that the oleo-resin is obtained.
The following are reputed to furnish the drug, but to what extent each contributes is not fully known.
1. Copaifera officinalis L. (C. Jacquini Desf.), a large tree of the hot coast region of New Granada as far north as Panama, of Venezuela and the island of Trinidad.
2. C. guianensis Desf., a tree of 30 to 40 feet high, very closely related to the preceding, native of Surinam, Cayenne, also of the Rio Negro between Manaos and Barcellos (Spruce). According to Bentham it seems to be the same species as the C. bijuga of Hayne.[878]
3. C. coriacea Mart. (C. cordifolia Hayne), a large tree found in the caatingas or dry woods of the Brazilian provinces of Bahia and Piauhy.
4. C. Langsdorffii Desf.[879] (C. nitida Hayne, C. Sellowii Hayne,? C. Jussieui Hayne), a polymorphous species, varying in the form and size of leaflets, and also in dimensions, being either a shrub, a small bushy tree, or a large tree of 60 feet high. Bentham admits, besides the type, three varieties:—β. glabra (C. glabra Vogel), γ. grandifolia, δ. laxa (C. laxa Hayne). The tree grows on dry campos, caatingas and other places in the provinces of S. Paulo, Minas Geraes, Goyaz, Mato Grosso, Bahia and Ceará; it is therefore distributed over a vast area. According to Gardner,[880] the Brazilian traveller, it yields an abundance of balsam.
In addition to these species, must be mentioned a tree described by Hayne and commonly cited under the name of Copaifera multijuga, as a special source of the drug shipped from Pará.[881] As its name implies, it is remarkable for the number of leaflets (6 to 10 pairs) on each leaf. But it is only known from some leaves in the herbarium of Martius which Bentham, who has examined them, informs us are unlike those of any Copaifera known to him, though certainly the leaflets are dotted with oil-vessels as in some species. In the absence of flowers and fruits, there is no sufficient evidence to prove that it belongs even to the genus Copaifera. It is not mentioned by Martius in his Systema Materiæ Medicæ Brasiliensis (1843) as a source of the drug.
=History=—Among the early notices of Brazil is a treatise by a Portuguese friar who had resided in that country from 1570 to 1600. The manuscript found its way to England, was translated, and was published by Purchas[882] in 1625. Its author notices many of the natural productions of the country, and among others Cupayba which he describes as a large tree from whose trunk, when wounded by a deep incision, there flows in abundance a clear oil much esteemed as a medicine.
Balsam. Copæ. yvæ is already enumerated in the 6th edition of the Pharmacopœa of Amsterdam, A.D. 1636.[883]
Father Cristoval d’Acuña,[884] who ascended the Amazon from Pará, arriving at Quito in 1638, mentions that the country affords very large Cassia fistula, excellent sarsaparilla, and the oils of Andirova (Carapa guianensis Aublet, Meliaceæ), and Copaiba, as good as balsam for curing wounds.
Piso and Marcgraf,[885] who in 1636 accompanied the Count of Nassau to the Dutch establishments in Brazil, each give an account of the Copaiba and the method of obtaining its oleo-resin. The former states that the tree grows in Pernambuco and the island of Maranhon, whence the balsam is conveyed in abundance to Europe.
[878] Hayne (1827) enumerated and figured 15 species, some of them founded on very imperfect materials. Bentham in the Flora Brasiliensis of Martius and Endlicher (fasc. 50, Leguminosæ, ii. 1870. pp. 239-244) admits only 11, one of which is doubtful as to the genus.
[879] Fig. in Bentley and Trimen, Med. Plants, part 32 (1878); Langsdorffii, not Lansdorffi, is to be written; see Pharm. Journ. ix. (1879) 773.
[880] MS. attached to specimens in the Kew Herbarium.
[881] “Alle Arten geben mehr oder weniger Balsam, und den meisten giebt die in der Provinz Para vorkommende Copaifera multijuga.”—Hayne, Linnæa, i. (1826) 429.
[882] Pilgrimes and Pilgrimage, Lond. iv. (1625) 1308.
[883] Pharm. Journ. vi. (1876) 1021.
[884] Nuevo Descubrimiento del gran Rio de las Amazonas, Madrid, 1641, No. 30.
[885] Hist. Nat. Brasiliæ:, 1648, Piso, 56, Marcgraf, 130.
The drug was formerly brought into European commerce by the Portuguese, and used to be packed in earthen pots pointed at the lower end; it often arrived in a very impure condition.[886] In the London Pharmacopœia of 1677, it was called Balsamum Capivi, which is still its most popular name.
=Secretion=—Karsten states that he observed resiniferous ducts, frequently more than an inch in diameter, running through the whole stem. He is of the opinion that the cell-walls of the neighbouring parenchyme are liquefied and transformed into the oleo-resin.[887] We are not able to offer any argument in favour of this opinion.
In the vessels already alluded to, the balsam sometimes collects in so large a quantity, that the trunk is unable to sustain the inward pressure, and bursts. This curious phenomenon is thus referred to in a letter addressed to one of us by Mr. Spruce:—“I have three or four times heard what the Indians assured me was the bursting of an old capivi-tree, distended with oil. It is one of the strange sounds that sometimes disturb the vast solitudes of a South American forest. It resembles the boom of a distant cannon, and is quite distinct from the crash of an old tree falling from decay which one hears not unfrequently.”
A similar phenomenon is known in Borneo. The trunks of aged trees of Dryobalanops aromatica contain large quantities of oleo-resin or Camphor Oil,[888] which appears to be sometimes secreted under such pressure that the vast trunk gives way. “There is another sound,” says Spenser St. John,[889] “only heard in the oldest forests, and that is as if a mighty tree were rent in twain. I often asked the cause, and was assured it was the camphor tree splitting asunder on account of the accumulation of camphor in some particular portion.”
=Extraction=—Balsam Capivi is collected by the Indians on the banks of the Orinoco and its upper affluents, and carried to Ciudad Bolivar (Angostura); some of this balsam reaches Europe by way of Trinidad. But it is obtained much more largely on the tributaries of the Caisquiari and Rio Negro (the Siapa, Içanna, Uaupés, etc.) and is sent down to Pará. Most of the northern tributaries of the Amazon, as the Trombetas and Nhamundá, likewise furnish a supply. According to Spruce, in the Amazon valley it is the tall virgin forest, Caaguaçú of the Brazilians, Monte Alto of the Venezuelans, that yields most of the oils and gum-resins, and not the low, dry caatingas, or the riparial forests. The same observant traveller tells us that in Southern Venezuela, capivi is known only as el Aceite de palo (wood-oil), the name Balsamo being that of the so-called Sassafras Oil, obtained from a species of Nectandra.
[886] Valmont de Bomare, Dict. d’Hist. Nat. i. (1775) 387.
[887] Botanische Zeitung, xv. (1857) 316.
[888] Motley in Hooker’s Journ. of Botany, iv. (1852) 201.
[889] Life in the Forests of the Far East, ii. (1862) 152.
Balsam Copaiba is also largely exported from Maracaibo where, according to Engel,[890] it is produced by C. officinalis, the Canime of the natives.
The finest sort, called by the collectors white copaiba, is met with in the province of Pará, where Cross[891] saw a tree of a circumference of more than 7 feet at 3 feet from the ground. Its trunk was clear of branches to a height of at least 90 feet. The collector commenced the work by hewing out with his axe a hole or chamber in the trunk about a foot square, at a height of two feet from the ground. The base or floor of the chamber should be carefully and neatly cut with a gentle upward slope, and it should also decline to one side, so that the balsam on issuing may run in a body until it reaches the outer edge. Below the chamber a pointed piece of bark is cut and raised, which, enveloped with a leaf, serves as a spout for conveying the balsam from the tree to the tin.[892] The balsam, continues Cross, came flowing in a moderate sized cool current, full of air bubbles. At times the flow stopped for several minutes, when a singular gurgling noise was heard, after which followed a rush of balsam. When coming most abundantly a pint jug would have been filled in the space of one minute. The whole of the wood cut through by the axeman was bedewed with drops of balsam; the bark is apparently devoid of it. Trees of the largest size in good condition will sometimes yield four “potos,” equal to 84 English imperial pints.
=Description=—Copaiba is more or less viscid fluid, varying in tint from a pale yellow to a light golden brown, of a peculiar aromatic, not unpleasant odour, and a persistent, acrid, bitterish taste. Pará copaiba newly imported is sometimes nearly colourless and almost as fluid as water.[893] The balsam is usually quite transparent, but there are varieties which remain always opalescent. Its sp. gr. varies from 0·940 to 0·993, according as the drug contains a greater or less proportion of volatile oil. Copaiba becomes more fluid by heat; if heated in a test tube to 200° C. for some time, it does not lose its fluidity on cooling. It is sometimes slightly fluorescent, it dissolves in several times its weight of alcohol 0·830 sp. gr., and generally in all proportions in absolute alcohol,[894] acetone, or bisulphide of carbon, and is perfectly soluble in an equal volume of benzol. Glacial acetic acid readily dissolves the resin but not the essential oil.
Copaiba that is rich in resin of an acid character, unites with the oxides of baryum, calcium, or magnesium, to form a gradually hardening mass, provided a small proportion of water is present. Thus 8 to 16 parts of balsam will combine as a stiff compound when gently warmed with 1 part of moistened magnesia; and still more easily with lime or baryta.
[890] Zeitschrift der Gesellschaft für Erdkunde zu Berlin, v. (1870) 435.
[891] Report to the Under Secretary of State for India, on the investigation and collecting of plants and seeds of the india-rubber trees of Pará and Ceara, and Balsam of Copaiba. March 1877,—8.
[892] See figure in the above Report.
[893] We saw such as this which had been imported into London in 1873; though regarded by the dealers with suspicion, we are not of opinion that it was sophisticated.
[894] Such is the case with some very authentic specimens collected for one of us in Central America by De Warszewicz, but other samples which we had up reason to suppose adulterated, left a certain amount of white residue when treated with twice their weight of alcohol sp. gr. 0·796.
Buignet has first shown (1861) that copaiba varies in its optical power. A sample from Trinidad examined by one of us was strongly dextrogyre, and also several samples imported in 1877 from Maturin (near Aragua, Venezuela), and Maracaibo into Hamburg, whereas we found Pará balsam to be levogyre.[895]
The Pará and Maranham balsams are regarded in wholesale trade as distinct sorts, and experienced druggists are able to distinguish them apart by odour and appearance, and especially by the greater consistence of the Maranham drug. Maracaibo balsam is reckoned as another variety, but is now rarely seen in the English market. West Indian copaiba is usually said to be of inferior quality, but except that it is generally opalescent, we know not on what precise grounds.
=Chemical Composition=—The balsam is a solution of resin in volatile oil; the latter constitutes about 40 to 60 per cent. of the balsam,[896] according to the age of the latter and its botanical origin. The oil has the composition C₁₅H₂₄; its boiling point is 245° C. or even higher. It smells and tastes like the balsam, and dissolves in from 8 to 30 parts of alcohol 0·830 sp. gr. The oil exhibits several modifications differing in optical as well as in other physical properties, but numerous samples of the drug, either dextrogyre or levogyre, invariably afforded us essential oils deviating to the left; their sp. gr. varies from about 0·88 to 0·91.
After the oil of copaiba has been removed by distillation, there remains a brittle amorphous resin of an acid character soluble both in benzol and amylic alcohol, and yielding only amorphous salts. Sometimes copaiba contains a small amount of crystallizable resin-acid, as first pointed out in 1829 by Schweitzer. By exposing a mixture of 9 parts of copaiba and two parts of aqueous ammonia (sp. gr. 0·95) to a temperature of-10° C., Schweitzer obtained crystals of the acid resin termed Copaivic Acid. They were analysed in 1834 by H. Rose, and exactly measured and figured by G. Rose. Hess (1839) showed that Rose’s and his own analyses assign to copaivic acid the formula C₂₀H₃₂O₂. It agrees with Maly’s abietic acid from colophony in composition, but not in any other way. Copaivic acid is readily soluble in alcohol, and especially in warmed copaiba itself; much less in ether. We have before us crystals, no doubt of copaivic acid, which have been spontaneously deposited in an authentic specimen of the oleo-resin of Copaifera officinalis from Trinidad, which we have kept for many years. The crystals may be easily dissolved by warming the balsam; on cooling the liquid, they again make their appearance after the lapse of some weeks. After recrystallization from alcohol they fuse at 116-117 C°., forming an amorphous transparent mass which quickly crystallizes if touched with alcohol.
An analogous substance, Oxycopaivic Acid, C₂₀H₂₈O₃, was examined in 1841 by H. von Fehling, who met with it as a deposit in Pará Copaiba. And lastly Strauss (1865) extracted Metacopaivic Acid, C₂₂H₃₄O₄, from the balsam imported from Maracaibo. He boiled the latter with soda-lye, which separated the oil; the heavier adjacent liquid was then mixed with chloride of ammonium, which threw down the salts of the amorphous resin-acid, leaving in solution those of the metacopaivic acid. The latter acid was separated by hydrochloric acid and recrystallization from alcohol. We succeeded in obtaining metacopaivic acid by washing the balsam with a dilute solution of carbonate of ammonium, and precipitating by hydrochloric acid. The precipitate dissolved in dilute alcohol yields the acid in small crystals, but to the amount of only about one per cent.
[895] Flückiger in Wiggers and Husemann’s Jahresbericht for 1867. 162, and for 1868. 140.
[896] Or 18 to 65 per cent., sp. gr. 0·915 to 0·995, according to Siebold (1877).
These resin-acids have a bitterish taste and an acid reaction; their salts of lead and silver are crystalline but insoluble; metacopaivate of sodium may be crystallized from its watery solution.
=Commerce=—The balsam is imported in barrels direct from Pará and Maranham, sometimes from Rio de Janeiro, and less often from Demerara, Angostura, Trinidad, Maracaibo, Savanilla, and Cartagena. It often reaches England by way of Havre and New York. In 1875 there were exported 10,150 kilogrammes from Savanilla, 99,800 lb. from Ciudad Bolivar (Angostura), and 65,243 kilos. from Pará.
=Uses=—Copaiba is employed in medicine on account of its stimulant action on the mucous membranes, more especially those of the urino-genital organs.
=Adulteration=—Copaiba is not unfrequently fraudulently tampered with before it reaches the pharmaceutist; and owing to its naturally variable composition, arising in part from its diverse botanical origin, its purity is not always easily ascertained.
The oleo-resin usually dissolves in a small proportion of absolute alcohol: should it refuse to do so, the presence of some fatty oil other than castor oil may be surmised. To detect an admixture of this latter, one part of the balsam should be heated with four of spirit of wine (sp. gr. 0·838). On cooling, the mixture separates into two portions, the upper of which will contain any castor oil present, dissolved in alcohol and the essential oil. On evaporation of this upper layer, castor oil may be recognized by its odour; but still more positively by heating it with caustic soda and lime, when œnanthol will be formed, the presence of which may be ascertained by its peculiar smell. By the latter test an admixture of even one per cent. of castor oil can be proved.
The presence of fatty oil in any considerable quantity is likewise made evident by the greasiness of the residue, when the balsam is deprived of its essential oil by prolonged boiling with water.
The admixture of some volatile oil with copaiba can mostly be detected by the odour, especially when the balsam is dropped on a piece of warmed metal. Spirit of wine may also be advantageously tried for the same purpose. It dissolves but very sparingly the volatile oil of copaiba: the resins of the latter are also not abundantly soluble in it. Hence, if shaken with the balsam, it would remove at once the larger portion of any essential oil that might have been added. For the recognition of Wood Oil if mixed with copaiba, see page 233, note 1.
=Substitutes=—Under this head two drugs deserve mention, namely Gurjun Balsam or Wood Oil, described at p. 88, and Oleo-resin of Hardwickia pinnata Roxb.—The tree, which is of a large size, belongs to the order Leguminosæ and is nearly related to Copaifera. According to Beddome,[897] it is very common in the dense moist forests of the South Travancore Ghats, and has also been found in South Canara. The natives extract the oleo-resin in exactly the same method as that followed by the aborigines of Brazil in the case of copaiba,—that is to say, they make a deep notch reaching to the heart of the trunk, from which after a time it flows out.
[897] Flora Sylvatica for Southern India, Madras, part 24 (1872), 255.
This oleo-resin, which has the smell and taste of copaiba, but a much darker colour, was first examined by one of us in 1865, having been sent from the India Museum as a sample of Wood Oil; it was subsequently forwarded to us in more ample quantity by Dr. Bidie of Madras. It is a thick, viscid fluid, which, owing to its intense tint, looks black when seen in bulk by reflected light; yet it is perfectly transparent. Viewed in a thin layer by transmitted light, it is light yellowish-green, in a thick layer vinous-red,—hence is dichromic. It is not fluorescent, nor is it gelatinized or rendered turbid by being heated to 130° C., thus differing from Wood Oil.[898] Broughton[899] obtained by prolonged distillation with water an essential oil to the extent of 25 per cent. from an old specimen, and of more than 40 per cent. from one recently collected. The oil was found to have the same composition as that of copaiba, to boil at 225° C., and to rotate the plane of polarization to the left. The resin[900] is probably of two kinds, of which one at least possesses acid properties. Broughton made many attempts, but without success, to obtain from the resin crystals of copaivic acid.
The balsam of Hardwickia has been used in India for gonorrhœa, and with as much success as copaiba.
GUMMI ACACIÆ
Gummi Arabicum; Gum Arabic; F. Gomme Arabique; G. Arabisches Gummi, Acacien-Gummi, Kordofan-Gummi.
=Botanical Origin=—Among the plants abounding in mucilage, numerous Acaciæ of various countries are in the first line. The species particularly known for affording the largest quantities of the finest gum arabic is Acacia Senegal[901] Willdenow (syn. Mimosa Senegal L., A. Verek Guillemin et Perrottet), a small tree not higher than 20 feet, growing abundantly on sandy soils in Western Africa, chiefly north of the river Senegal, where it constitutes extensive forests. It is called by the negroes Verek. The same tree is likewise found in Southern Nubia, Kordofan, and in the region of the Atbara in Eastern Africa, where it is known as Hashab. It has a greyish bark, the inner layers of which are strongly fibrous, small yellowish flowers densely arranged in spikes 2 to 3 inches long, and exceeding the bipinnate leaves, and a broad legume 3 to 4 inches in length containing 5 to 6 seeds.
[898] It may be further distinguished from Wood Oil as well as from copaiba, if tested in the following simple manner:—Put into a tube 19 drops of bisulphide of carbon and one drop of the oleo-resin, and shake them together. Then add one drop of a mixture of equal parts of strong sulphuric and nitric (1·42) acids. After a little agitation the appearance of the respective mixtures will be as follows:—
Copaiba—Colour faint reddish-brown, with deposit of resin on sides of tube.
Wood Oil—Colour intense purplish-red, becoming violet after some minutes.
Oleo-resin of Hardwickia—No perceptible alteration; the mixture pale greenish yellow.
By this test the presence in copaiba of one-eighth of its volume of Wood Oil may be easily shown.
[899] Beddome, op. cit.
[900] See also Hazlett, Madras Monthly Journ. of Med. Science, June 1872.
[901] Figures in Guillemin and Perrottet Floræ Senegamb. tent. 1830, p. 246, tab. 56; also Bentley and Trimen, Med. Plants, part 17 (1877).
According to Schweinfurth,[902] it is this tree exclusively that yields the fine white gum of the countries bordering the Upper Nile, and especially of Kordofan. He states that only brownish or reddish sorts of gum are produced by the Talch, Talha or Kakul, Acacia stenocarpa Hochstetter, by the Ssoffar, A. fistula Schweinf. (A. Seyal Delile, var. Fistula), as well as by the Ssant or Sont, A. nilotica Desfont (A. arabica Willd.). These trees grow in north-eastern Africa; the last named is, moreover, widely distributed all over tropical Africa as far as Senegambia,[903] Mozambique and Natal, and also extends to Sindh, Gujarat[904] and Central India. We find even the first sort, “Karami,” of gum exported from the Somali coast,[905] to be inferior to good common Arabic gum. Hildebrandt (1875) mentions that gum is there largely collected from Acacia abyssinica Hochst. and A. glaucophylla Steudel.
=History=—The history of this drug carries us back to a remote antiquity. The Egyptian fleets brought gum from the gulf of Aden as early as the 17th century B.C. Thus in the treasury of king Rhampsinit (Ramses III.) at Medinet Abu, there are representations of gum-trees, together with heaps of gum. The symbol used to signify gum, is read Kami-en-punt. i.e. gum from the country of Punt. This, in all probability, includes both the Somali coast as well as that of the opposite parts of Arabia (see article Olibanum, p. 136). Thus, gum is of frequent occurrence in Egyptian inscriptions; sometimes mention is made of gum from Canaan. The word kami is the original of the Greek κόμμι, whence through the Latin our own word gum.[906]
The Egyptians used gum largely in painting; an inscription exists which states that in one particular instance a solution of Kami (gum) was used to render adherent the mineral pigment called chesteb,[907] the name applied to lapis lazuli or to a glass coloured blue by cobalt.
Turning to the Greeks, we find that Theophrastus in the 3rd and 4th century B.C. mentioned Κόμμι as a product of the Egyptian Ἂκανθα, of which tree there was a forest in the Thebaïs of Upper Egypt. Strabo also, in describing the district of Arsinöe, the modern Fayûm, says that gum is got from the forest of the Thebaïc Akanthe.
Celsus in the 1st century mentions Gummi acanthinum; Dioscorides and Pliny also describe Egyptian gum, which the latter values at 3 denarii [2_s._] per lb.
In those times gum no doubt used to be shipped from north-eastern Africa to Arabia; there is no evidence showing that Arabia itself had ever furnished the chief bulk of the drug. The designation gum arabic occurs in Diodorus Siculus (2, 49) in the first century of our era, also in the list of goods of Alexandria mentioned in our article on Galbanum.
[902] Aufzählung und Beschreibung der Acacien-Artendes Nilgebiets.—Linnæa, i. (1867) 308-376, with 21 plates. Schweinfurth’s observations are strongly confirmed by an account of the commerce of Khartum in the Zeitschrift für Erdkunde, ii. (1867, Berlin) 474.
[903] The A. Adansonii Guill. et Perr. is the same tree.
[904] The “Kikar” of the Punjaub, or “Babul” or “Babur” of Central India.
[905] As presented to me by Capt. Hunter of Aden, July 1877.—F. A. F..
[906] We have to thank Professor Dümichen for most of the information relating to Egypt, which may be partly found in his own works, and partly in those of Brugsch, Ebers, and Lepsius.
[907] Lepsius, Abhandl. der Akademie der Wissensch. zu Berlin for 1871, p. 77. 126. Metalle in den Aegyptischen Inschriften.
Gum was employed by the Arabian physicians and by those of the school of Salerno, yet its utility in medicine and the arts was but little appreciated in Europe until a much later period. For the latter purpose at least the gummy exudations of indigenous trees were occasionally resorted to, as distinctly pointed out about the beginning of the 12th century, by Theophilus or Rogker:[908] “gummi quot exit de arbore ceraso vel pruno.“
During the middle ages, the small supplies that reached Europe were procured through the Italian traders from Egypt and Turkey. Thus Pegolotti,[909] who wrote a work on commerce about A.D. 1340, speaks of gum arabic as one of the drugs sold at Constantinople by the pound not by the quintal. Again, in a list of drugs liable to duty at Pisa in 1305,[910] and in a similar list relating to Paris in 1349,[911] we find mention of gum arabic. It is likewise named by Pasi,[912] in 1521, as an export from Venice to London.
Gum also reached Europe from Western Africa, with which region the Portuguese had a direct trade as early as 1449.
=Production=—Respecting the origin of gum in the tribe Acaciæ, no observations have been made similar to those of H. von Mohl on tragacanth.[913]
It appears that gum generally exudes from the trees spontaneously, in sufficient abundance to render wounding the bark superfluous. The Somali tribes of East Africa, however, are in the habit of promoting the outflow by making long incisions in the stem and branches of the tree.[914] In Kordofan the lumps of gum are broken off with an axe, and collected in baskets.
The most valued product, called Hashabi gum, from the province of Dejara in Kordofan, is sent northward from Bara and El Obeid to Dabbeh on the Nile, and thence down the river to Egypt; or it reaches the White Nile at Mandjara.
A less valuable gum, known as Hashabi el Jesire, comes from Sennaar on the Blue Nile; and a still worse from the barren table-land of Takka, lying between the eastern tributaries of the Blue Nile and the Atbara and Mareb; and from the highlands of the Bisharrin Arabs between Khartum and the Red Sea. This gum is transported by way of Khartum or El Mekheir (Berber), or by Suakin on the Red Sea. Hence, the worst kind of gum is known in Egypt as Samagh Savakumi (Suakin Gum).
According to Munzinger,[915] a better sort of gum is produced along the Samhara coast towards Berbera, and is shipped at Massowa. Some of it reaches Egypt by way of Jidda, which town being in the district of Arabia called the Hejaz, the gum thence brought receives the name of Samagh Hejazi; it is also called Jiddah or Gedda Gum. The gums of Zeila, Berbera and the Somali country about Gardafui, are shipped to Aden, or direct to Bombay. A little gum is collected in Southern Arabia, but the quantity is said to be insignificant.[916]
[908] Schedula diversarum artium, Ilg’s edition in Eitelberger’s Quellenschriften für Kunstgeschichte, vii. (1874) 60.
[909] Della Decima e di varie altre gravezze imposte dal commune di Firenze, iii. (1766) 18.
[910] Bonaini, Statuti inediti della città di Pisa, Firenze, iii. (1857) 106. 114.
[911] Ordonnances des Rois de France, ii. (1729) 310.
[912] Tariffa de pesi e misure, Venet. 1521. 204. First edition, 1503.
[913] See, however, Möller, Academy of Vienna, Sitzungsberichte, June 1875.
[914] Vaughan (Drugs of Aden), Pharm. Journ. xii. (1853) 226.
[915] Private information to F. A. F..
[916] Vaughan, l.c.
In the French colony of Senegal, gum, which is one of its principal productions, is collected chiefly in the country lying north of the river, by the Moors who exchange it for European commodities. The gathering commences after the rainy season in November when the wind begins to set from the desert, and continues till the month of July. The gum is shipped for the most part to Bordeaux. The quantity annually imported into France since 1828 from Senegal is varying from between 1½ to 5 millions of kilogrammes.
=Description=—Gum arabic does not exhibit any very characteristic forms like those observable in gum tragacanth. The finest white gum of Kordofan, which is that most suitable for medicinal use, occurs in lumps of various sizes from that of a walnut downwards. They are mostly of ovoid or spherical form, rarely vermicular, with the surface in the unbroken masses, rounded,—in the fragments, angular. They are traversed by numerous fissures, and break easily and with a vitreous fracture. The interior is often less fissured than the outer portion. At 100° C. the cracks increase, and the gum becomes extremely friable. In moist air, it slowly absorbs about 6 per cent. of water.
The finest gum arabic is perfectly clear and colourless; inferior kinds have a brownish, reddish or yellowish tint of greater or less intensity, and are more or less contaminated with accidental impurities such as bark. The finest white gum turns black and assumes an empyreumatic taste, when it is kept for months at a temperature of about 98° C., either in an open vessel, or enclosed in a glass tube, after having been previously dried over sulphuric acid or not.
An aqueous solution of gum deviates the plane of polarization 5° to the left in a column 50 mm. long; but after being long kept, it becomes strongly acid, the gum having been partly converted into sugar, and its optical properties are altered. An alkaline solution of cupric tartrate is not reduced by solution of gum even at a boiling heat, unless it contains a somewhat considerable proportion of sugar, extractable by alcohol, or a fraudulent admixture of dextrin.
We found the sp. gr. of the purest pieces of colourless gum dried in the air at 15° C., to be 1·487; but it increases to 1·525, if the gum is dried at 100°.
The foregoing remarks apply chiefly to the fine white gum of Kordofan, the Picked Turkey Gum or White Sennaar Gum of druggists. The other sorts which are met with in the London market are the following:—
1. Senegal Gum—As stated above, this gum is an important item of the French trade with Africa, but is not much used in England. Its colour is usually yellowish or somewhat reddish, and the lumps, which are of large size, are often elongated or vermicular. Moreover Senegal gum never exhibits the numerous fissures seen in Kordofan gum, so that the masses are much firmer and less easily broken. In every other respect, whether chemical or optical, we find[917] Senegal gum and Kordofan gum to be identical; and the two, notwithstanding their different appearance, are produced by one and the same species of Acacia, namely Acacia Senegal.
2. Suakin Gum, Talca or Talha Gum, yielded by Acacia stenocarpa, and by A. Seyal var. Fistula, is remarkable for its brittleness, which occasions much of it to arrive in the market in a semi-pulverulent state. It is a mixture of nearly colourless and of brownish gum, with here and there pieces of a deep reddish-brown. Large tears have a dull opaque look, by reason of the innumerable minute fissures which penetrate the rather bubbly mass. It is imported from Alexandria.
3. Morocco, Mogador or Brown Barbary Gum—consists of tears of moderate size, often vermiform, and of a rather uniform, light, dusky brown tint. The tears which are internally glassy become cracked on the surface and brittle if kept in a warm room; they are perfectly soluble in water. The above mentioned Acacia nilotica is supposed to be the source of the gum exported from Morocco, and also from Fezzan.
Gums of various kinds, including the resin Sandrac, were exported from Morocco in the year 1872 to the extent of 5110 cwt., a quantity much below the average.[918]
4. Cape Gum—This gum, which is uniformly of an amber brown, is produced in plenty in the Cape Colony, as a spontaneous exudation of Acacia horrida Willd. (A. Karroo Hayne, A. capensis Burch.), a large tree, the Doornboom, Wittedoorn or Karródoorn of the Cape colonists, the commonest tree of the lonely deserts of South Africa. The Blue Book of the Cape Colony, published in 1873, states the export of gum in 1872 as 101,241 lb.
5. East India Gum—The best qualities consist of tears of various sizes, sometimes as large as an egg, internally transparent and vitreous, of a pale amber or pinkish hue, completely soluble in water. This gum is largely shipped from Bombay, but is almost wholly the produce of Africa; the imports into Bombay from the Red Sea ports, Aden and the African Coast in the year 1872-73, were 14,352 cwt. During the same year the shipments from Bombay to the United Kingdom amounted to 4,561 cwt.[919]
6. Australian Gum, Wattle Gum—This occurs in large hard globular tears and lumps, occasionally of a pale yellow, yet more often of an amber or of a reddish-brown hue. It is transparent and entirely soluble in water; the mucilage is strongly adhesive, and said to be less liable to crack when dry than that of some other gums. The solution, especially that of the darker and inferior kinds, contains a little tannin, evidently derived from the very astringent bark which is often attached to the gum.
A. pycnantha Benth.; A. decurrens Willd. (A. mollissima Willd., A. dealbata Link), Black or Green Wattle-tree of the colonists, and A. homalophylla A. Cunn., are the trees which furnish the gum arabic of Australia.[920]
[917] Flückiger, in the Jahresbericht of Wiggers and Husemann, 1869. 149.
[918] Consular Reports, August, 1873. 917.
[919] Statement of the Trade and Navigation of the Presidency of Bombay for 1872-73, pt. ii. 34. 77.
[920] P. von Müller, Select Plants for industrial culture in Victoria. 1876; 2. 4.
=Chemical Characters and Composition=—At ordinary temperatures gum dissolves very slowly and without affecting the thermometer in an equal weight of water, forming a thick, glutinous, slightly opalescent liquid, having a mawkish taste and decidedly acid reaction. At higher temperatures the dissolution of gum is but slightly accelerated, and water does not take up a much larger quantity even at 100°. The finest gum dried at 100° C. forms with two parts of water a mucilage of sp. gr. 1·149 at 15° C.
This solution mixes with glycerine, and the mixture may be evaporated to the consistence of a jelly without any separation taking place. Solid gum in lumps, on the contrary, is but little affected by concentrated glycerine. In other liquids, gum is insoluble or only slightly soluble, unless there is a considerable quantity of water present. Thus 100 parts of spirit of wine containing 22 volumes per cent. of alcohol, dissolve 57 parts of gum; spirit containing 40 per cent. of alcohol takes up 10 parts, and spirit of 50 per cent. only 4 parts. Aqueous alcohol of 60 per cent. no longer dissolves gum, but extracts from it a small quantity (⅓ to ½ per cent. according to the variety) of resin colouring matter, glucose, calcium chloride, and other salts.
Neutral acetate of lead does not precipitate gum arabic mucilage; but the basic acetate forms, even in a very dilute solution, a precipitate of definite constitution.
Soluble silicates, borates, and ferric salts render gum solution turbid, or thicken it to a jelly. It is not a compound of gum with any of these substances which is formed, but in the cases of the first, basic silicates separate. No alteration is produced by silver salts, mercuric chloride or iodine. Ammonium oxalate throws down the lime contained in a solution of gum. Gum dissolves in an ammoniacal solution of cupric oxide. Acted upon by nitric acid, mucic acid is produced.
Small, air-dried lumps of gum lose by desiccation over concentrated sulphuric acid (or by heating them in the water-bath) 12 to 16 per cent. of water. If gum independently of its amount of lime, be presented by the formula C₁₂H₂₂O₁₁ + 3H₂O, the loss of 3 molecules of water will correspond to a decrease in weight of 13·6 per cent.; in carefully selected colourless pieces, we have found it to amount to 13·14 per cent. At a temperature of about 150° C., gum parts with another molecule of water, and partly loses its solubility and assumes a brownish hue and empyreumatic taste. Gum already by keeping it for a week at a temperature not exceeding 95° C. gradually acquires a decidedly empyreumatic taste. We have also observed, on the other hand, a fine white gum affording an imperfect solution which was glairy, like the mucilage of marshmallow, but in no other respect could we find that it differed from ordinary gum. On exposing it for some days to a temperature of 95° C., it afforded a solution of the usual character.
When gum arabic is dissolved in cold water and the solution is slightly acidulated with hydrochloric acid, alcohol produces it in a precipitate of Arabin or Arabic Acid. It may be also prepared by placing a solution of gum (1 gum + 5 water), acidulated with hydrochloric acid, on a dialyser, when the calcium salt will diffuse out, leaving behind a solution of arabin.
Solution of arabin differs from one of gum in not being precipitated by alcohol. Having been dried, it loses its solubility, merely swelling in water, but not dissolving even at a boiling heat. If an alkali is added, it forms a solution like ordinary gum. Neubauer who observed these facts (1854-57) showed that gum arabic is essentially an acid calcium salt of arabic acid.
Arabic Acid dried at 100° C. has the composition C₁₂H₂₂O₁₁, and gives up H₂O when it unites with bases. It has however a great tendency to form salts containing a large excess of acid. An acid calcium arabate of the composition (C₁₂H₂₁O₁₁)₂Ca + 3 (C₁₂H₂₂O₁₁ + 5 OH) would afford by incineration 4·95 per cent. of calcium carbonate. Nearly this amount of ash is in fact sometimes yielded by gum. The most carefully selected colourless pieces of it yield from 2·7 to 4 per cent. of ash, consisting mainly of calcium carbonate, but containing also carbonates of potassium and magnesium. Phosphoric acid appears never to occur in gums.
Natural gum may therefore be regarded as a salt of arabic acid having a large excess of acid, or perhaps as a mixture of such salts of calcium, potassium and magnesium. It is to the presence of these bases, which are doubtless derived from the cell-wall from which the gum exuded, that gum owes its solubility.
It still remains unexplained why certain gums, not unprovided with mineral constituents, merely swell up in water without dissolving, thus materially differing from gum arabic. There is also a marked difference between gum arabic and many other varieties of gum or mucilage, which immediately form a plumbic compound if treated with neutral acetate of lead. The type of the swelling, but not really soluble gums, is Tragacanth, but there are a great many other substances of the same class, some of them perfectly resembling gum arabic in external appearance. The name of Bassora gum has also been applied to the latter kinds.
=Commerce=—The imports of Gum Arabic into the United Kingdom have been as follows:—
1871 1872 76,136 cwt. 42,837 cwt. value £250,088. value £123,080.
The country whence by far the largest supplies are shipped, is Egypt.
=Uses=—Gum is employed in medicine rather as an adjuvant than as possessing any remedial powers of its own.
=Substitutes=—A great number of trees are capable of affording gums more or less similar to gum arabic. There is to be mentioned for instance Prosopis glandulosa Torrey, a tree growing from 30 to 40 feet in height, occurring very abundantly in Texas, and extending as far west as the Colorado and the gulf of California. It is universally known by its Mexican name Mesquite. It belongs to the same suborder of the Mimosæ like the Acaciæ tribe of the Adenanthereæ. Mesquite gum agrees not with the fine description, but with the inferior sorts of gum arabic, and is sometimes used in America,[921] since 1854, in the manufacture of confectionery and the arts.
Feronia Gum, or Wood Apple Gum. This is the produce of Feronia Elephantum Correa, a spiny tree, 50 to 60 feet high, of the order of Aurantiaceæ, common throughout India from the hot valleys of the Himalaya to Ceylon, and also found in Java. There exudes from its bark abundance of gum, which appears not to be collected for exportation per se, but rather to be mixed indiscriminately with other gum, as that of Acacia.
[921] See Proceedings of Am. Pharm. Assoc. 1875. 647; Am. Journ. of Pharm. 1878. 480.
Feronia gum sometimes forms small roundish transparent, almost colourless tears, more frequently stalactitic or knobby masses, of a brownish or reddish colour, more or less deep. In an authentic sample, for which we are indebted to Dr. Thwaites of Ceylon, horn-shaped pieces about ½ an inch thick and two inches long also occur.
Dissolved in two parts of water, it affords an almost tasteless mucilage, of much greater viscosity than that of gum arabic made in the same proportions. The solution reddens litmus, and is precipitated like gum arabic by alcohol, oxalate of ammonium, alkaline silicates, perchloride of iron, but not by borax. Moreover, the solution of Feronia gum is precipitated by neutral acetate of lead or caustic baryta, but not by potash. If the solution is completely precipitated by neutral acetate of lead, the residual liquid will be found to contain a small quantity of a different gum, identical apparently with gum arabic, inasmuch as it is not thrown down by acetate of lead. If the lime is precipitated from the Feronia mucilage by oxalate of potassium, the gum partially loses its solubility and forms a turbid liquid.
From the preceding experiments, it follows that a larger portion of Feronia gum is by no means identical with gum arabic. The former, when examined in a column of 50 mm. length, deviates the rays of polarized light 0°·4 to the right,—not to the left as gum arabic. This was, we believe, the first instance of a dextrogyre gum;[922] Scheibler has afterwards shown (1873) that there are also dextrogyre varieties among the African gum from Sennar. Gum arabic may be combined with oxide of lead; the compound (arabate of lead) contains 30·6 per cent. of oxide of lead, whereas the plumbic compound of Feronia gum, dried at 110° C., yielded us only 14·76 per cent. of PbO. The formula (C₁₂H₂₁O₁₁)₂Pb + 2(C₁₂H₂₂O₁₁) supposes 14·2 per cent. of oxide of lead.
Feronia gum repeatedly treated with fuming nitric acid produces abundant crystals of mucic acid. We found our sample of the gum to yield 17 per cent. of water, when dried at 110° C. It left 3·55 per cent. of ash.