Chapter XII: Part 12

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.