I.—PHÆNOGAMOUS OR FLOWERING PLANTS. (continued 20)

Uses—The seeds are used in cattle medicines, occasionally as a condiment, but chiefly, we believe, to give a fiery pungency to cordials.

ORCHIDACEÆ.

SALEP.

Radix Salep, Radix Satyrii; Salep; F. Salep; G. Salepknollen.

Botanical Origin—Most, if not all, species of Orchis found in Europe and Northern Asia are provided with tubers which, when duly prepared, are capable of furnishing salep. Of those actually so used, the following are the more important, namely—Orchis mascula L., O. Morio L., O. militaris L., O. ustulata L., O. pyramidalis L., O. coriophora L., and O. longicruris Link. These species which have the tubers entire are natives of the greater part of Central and Southern Europe, Turkey, the Caucasus and Asia Minor.[2436]

The following species with palmate or lobed tubers have a geographical area no less extensive, namely O. maculata L., O. saccifera Brongn., O. conopsea L., and O. latifolia L. The last named reaches North-Western India and Tibet; and O. conopsea occurs in Amurland in the extreme east of Asia.

The salep of the Indian bazaars, known as Sālib misrī, for fine qualities of which the most extravagant prices are paid by wealthy orientals, is derived from certain species of Eulophia, as E. campestris Lindl., E. herbacea Lindl., and probably others.[2437]

History—Under the superstitious influence of the so-called doctrine of signatures,[2438] salep[2439] has had for ages a reputation in Eastern countries as a stimulant of the generative powers; and many Europeans who have lived in India, although not prepared to admit the extravagant virtues ascribed to it by Hindus and Mahommedans, yet regard it as a valuable nutrient in the sick-room.

The drug was known to Dioscorides and the Arabians, as well as to the herbalists and physicians of the middle ages, by whom it was mostly prescribed in the fresh state. Gerarde (1636) has given excellent figures of the various orchids whose tubers, says he, “our age useth.”

Geoffroy[2440] having recognized the salep imported from the Levant to be the tubers of an orchis, pointed out in 1740 how it might be prepared from the species indigenous to France.

Collection—The tubers are dug up after the plant has flowered, and the shrivelled ones having been thrown aside, those which are plump are washed, strung on threads and scalded. By this process their vitality is destroyed, and the drying is easily effected by exposure to the sun or to a gentle artificial heat. Though white and juicy when fresh, they become by drying hard and horny, and lose their bitterish taste and peculiar odour.

Salep is largely collected near Melassa (Milas) and Mughla (or Moola), south-east of Smyrna, and also brought there from Mersina, opposite the north-eastern cape (Andrea) of Cyprus. The drug found in English trade is mostly imported from Smyrna. That sold in Germany is partly obtained from plants growing wild in the Taunus mountains, Westerwald, Rhön, the Odenwald, and in Franconia. Salep is also collected in Greece, and used in that country and Turkey in the form of decoction, which is sweetened with honey and taken as an early morning drink.[2441] The salep of India is produced on the hills of Afghanistan, Beluchistan, Kabul and Bokhara;[2442] the Neilgherry Hills in the south, and even Ceylon are said likewise to afford it.

Description—Levant salep, such as is found in the English market, consists of tubers half an inch to an inch in length, of ovoid or oblong form, often pointed at the lower end, and rounded at the upper where is a depressed scar left by the stem; palmate tubers are unfrequent. They are generally shrunken and contorted, covered with a roughly granular skin, pale brown, translucent, very hard and horny, with but little odour and a slight not unpleasant taste. After maceration in water for several hours, they regain their original form and volume. German salep is more translucent and gummy-looking, and has the aspect of being more trimmed and prepared.

Microscopic Structure—The fresh tuber exhibits on transverse section a few outer rows of thin-walled cells rich in starch. These are followed by parenchyme of elongated colourless cells likewise containing starch, and isolated bundles of acicular crystals of oxalate of calcium. In this parenchyme, there are numerous larger cells filled with homogenous mucilage. Small vascular bundles are irregularly scattered throughout the tuber. In Orchis mascula and O. latifolia the starch grains are nearly globular, and about 25 mkm. in diameter. In dried salep the cell-walls are distorted and the starch grains agglomerated.

Chemical Composition—The most important constituent of salep is a sort of mucilage, the proportions of which according to Dragendorff (1865) amounts to 48 per cent.; but it is doubtless subject to great variation. Salep yields this mucilage to cold water, forming a solution which is turned blue by iodine, and mixes clearly with neutral acetate of lead like gum arabic. On addition of ammonia, an abundant precipitate is formed. Mucilage of salep precipitated by alcohol and then dried, is coloured violet or blue, if moistened with a solution of iodine in iodide of potassium. The dry mucilage is readily soluble in ammoniacal solution of oxide of copper; when boiled with nitric acid, oxalic, but not mucic acid is produced. In these two respects, the mucilage of salep agrees with cellulose, rather than with gum arabic. In the large cells in which it is contained, it does not exhibit any stratification, so that its formation does not appear due to a metamorphosis of the cell-wall itself. Mucilage of salep contains some nitrogen and inorganic matter, of which it is with difficulty deprived by repeated precipitation by alcohol.

It is to the mucilage just described that salep chiefly owes its power of forming with even 40 parts of water a thick jelly, which becomes still thicker on addition of magnesia or borax. The starch however assists in the formation of this jelly; yet its amount is very small, or even nil in the tuber bearing the flowering stem, whereas the young lateral tuber abounds in it. The starch so deposited is evidently consumed in the subsequent period of vegetation, thus explaining the fact that tubers are found, the decoction of which is not rendered blue by iodine. Salep contains also sugar and albumin, and when fresh, a trace of volatile oil. Dried at 110° C., it yields 2 per cent. of ash, consisting chiefly of phosphates and chlorides of potassium and calcium (Dragendorff).

Commerce—The shipments of salep from Smyrna are about 5000 okkas (one okka equal to 283·2 lb. avdp. = 128·5 kilogrammes) annually.

Uses—Salep possesses no medicinal powers; but from its property of forming a jelly with a large proportion of water, it has come to be regarded as highly nutritious,—a popular notion in which we do not concur. A decoction flavoured with sugar and spice, or wine, is an agreeable drink for invalids, but is not much used in England.[2443]

VANILLA.

Vanilla;[2444] F. and G. Vanille.

Botanical Origin—Vanilla planifolia Andrews—Indigenous to the hot regions (tierra caliente) of Eastern Mexico, diffused by cultivation through other tropical countries. The plant, which is rather fleshy and has large greenish inodorous flowers,[2445] grows in moist, shady forests, climbing the trees by means of its aërial roots.

History—The Spaniards found vanilla in use in Mexico as a condiment to chocolate, and by them it was brought to Europe; but it must have long remained very scarce, for Clusius, who received a specimen in 1602 from Morgan, apothecary to Queen Elizabeth, described it as Lobus oblongus aromaticus, without being in the least aware of its native country or uses.[2446] In the Thesaurus of Hernandez there is a figure and account of the plant under the name of Araco aromatico.[2447]

In the time of Pomet (1694) vanilla was imported by way of Spain, and was much used in France for flavouring chocolate and scenting tobacco. It had a place in the materia medica of the London Pharmacopœia of 1721, and was well known to the druggists of the first half of the 18th century, after which it seems to have gradually disappeared from the shops. Of late times it has been imported in great abundance, and is now plentifully used, not only by the chocolate manufacturer, but also by the cook and confectioner.

Cultivation—The culture of vanilla is very simple. Shoots about three feet long having been fastened to trees, and scarcely touching the ground, soon strike roots on to the bark, and form plants which commence to produce fruit in three years, and remain productive for thirty to forty.

The fertilization of the flower is naturally brought about by insect agency. This was practised as early as 1830 by Neumann in the Jardin des Plantes at Paris, and in 1837 by Morren,[2448] the director of the Botanical Garden of Liège, since which the production of the pods has been successfully carried on in all tropical countries[2449] without the aid of insects. Even in European forcing houses the plant produces fruits of full size, which for aroma bear comparison with those of Mexico.

In vanilla plantations the pods are not allowed to arrive at complete maturity, but are gathered when their green colour begins to change. According to the statements of De Vriese,[2450] they are dried by a rather circuitous process, namely by exposing them to heat alternately uncovered, and wrapped in woollen cloths, whereby they are artificially ripened, and acquire their ultimate aroma and dark hue. They are then tied together into small bundles.

In Réunion the drying of the pods is performed since 1857 by dipping them previously in boiling water.

Description—The fruit when fresh is of the thickness of the little finger, obscurely triquetrous, opening longitudinally by two unequal valves. It is fleshy, firm, smooth, and plump; when cut transversely it exudes an inodorous slimy juice, abounding in spiculæ of oxalate of calcium.[2451] It is one-celled, with a three-sided cavity, from each wall of which projects a two-branched placenta, each branch subdividing into two backward-curling lobes. There are thus in all 12 ridges, which traverse the fruit lengthwise, and bear the seeds. Fine hair-like papillæ line as a thick fringe the three angles of the cavity, and secrete the odorous matter, which after drying is diffused through the whole pod. The papillæ likewise contain drops of oil, which is freely absorbed by the paper in which a pod is wrapped. That the odorous matter is not resident in the fleshy exterior mass we have ascertained by slicing off this portion of a fresh fruit and drying it separately; the interior alone proved to be fragrant.

The vanilla of commerce occurs in the form of fleshy, flexible, stick-like pods, 3 to 8 inches long, and ³/₁₀ to ⁴/₁₀ of an inch wide, of a compressed cylindrical form, attenuated and hooked at the stalk end. The surface is finely furrowed lengthwise, shining, unctuous, and often beset with an efflorescence of minute colourless crystals. The pod splits lengthwise into two unequal valves, revealing a multitude of minute, shining, hard, black seeds of lenticular form, imbedded in a viscid aromatic juice.

The finest vanilla is the Mexican. Bourbon Vanilla, which is the more plentiful, is generally shorter and less intense in colour, and commands a lower price.

Microscopic Structure—The inner half of the pericarp contains about 20 vascular bundles, arranged in a diffuse ring. The epidermis is formed of a row of tabular thick-walled cells, containing a granular brown substance. The middle layer of the pericarp is composed of large thin-walled cells, the outer of which are axially extended, while those towards the centre have a cubic or spherical form. All contain drops of yellowish fat and brown granular masses, which do not decidedly exhibit the reaction of tannin. The tissue further encloses needles of oxalate of calcium and prisms of vanillin.

On the walls of the outer cells of the pericarp[2452] are deposited spiral fibres, which occur still more conspicuously in the aërial roots and in the parenchyme of the leaves of other orchids. The placentæ are coated with delicate, thin-walled cells.

Chemical Composition—Vanilla owes the fragrance for which it is remarkable to Vanillin, which is found in a crystalline state in the interior or on the surface of the fruit, or dissolved in the viscid oily liquid surrounding the seeds. It was formerly regarded as cinnamic or benzoic acid, and then as cumarin, until Gobley (1858) demonstrated its peculiar nature.

The admirable researches of Tiemann and Haarmann performed in Hofmann’s laboratory at Berlin (1874-1876) have shown that vanillin is constituted according to the formula

OCH₃

C₆H₃ OH.

CHO

It is the aldehyde. It is the aldehyde of methyl-protocatechuic acid, and like other aldehydes yields a crystallized compound with the bisulphites of alkalis. This is obtained by shaking an ethereal extract (e) of vanilla, with a saturated solution of bisulphite of sodium. The vanillin compound remaining in aqueous solution is mixed with sulphuric acid and ether; the latter on evaporation affords crystals of vanillin. They melt at 81°, and may be sublimed by cautiously heating them. Vanillin is but sparingly soluble in cold water, and requires about 11 parts of it at 100° C. for solution; it strikes a fine dark violet with perchloride of iron.

The said chemists have further demonstrated that vanillin may be formed artificially. In the sapwood of pines there occurs a substance called Coniferin, C₁₆H₂₂O₈ + 2 H₂O, first observed in 1861 by Hartig. By means of emulsin coniferin taking up H₂O, can be resolved into sugar and another crystallizable substance:—C₁₆H₂₂O₈ + H₂O = C₆H₁₂O₆ + C₁₀H₁₂O₃. The second substance thus derived may be collected by means of ether, which dissolves neither coniferin nor sugar. By oxidizing it, or coniferin itself, by bichromate of potassium and sulphuric acid, Vanillin is obtained. The latter has been for sometime manufactured in that way by Tiemann, but now eugenol (see p. 285) is used for that purpose. Another source for vanillin is benzoin (p. 409).

The amount of vanillin was stated by Haarmann and Tiemann to be 1·69 per cent. in Mexican vanillin, from 1·9 to 2·48 in the Bourbon variety, and 2·75 in that from Java. The so-called Vanillon affords only 0·4 to 0·7 per cent. of vanillin.

From the above-mentioned ethereal solution (e), after it has been deprived of vanillin, vanillate of sodium may be removed by a dilute solution of carbonate of sodium. On acidulating the aqueous solution crystals of vanillic acid,

OCH₃

C₆H₃ OH.

COOH

are precipitated. If the ether of the solution (e), after it has been treated with carbonate of sodium, is allowed to evaporate, a mixture of fatty substances and a resin are obtained. The latter has a peculiar odour, somewhat suggestive of castoreum; vanillic acid is almost inodorous.

Leutner (1872) also found in vanilla fatty and waxy matter 11·8, resin 4·0, gum and sugar 16·5 per cent.; and obtained by incineration of the drug 4·6 per cent. of ash.

Production and Commerce—The chief seats of vanilla-production in Mexico are the slopes of the Cordilleras, north-west of Vera Cruz, the centre of the culture being Jicaltepec, in the vicinity of Nautla.[2453] The finest specimens were contributed in 1878 to the Paris Exhibition from Agapito, Fonticilla, Misantla, Papantla, also from Teziutlan, province of Puebla. There are likewise “Baynillales,” plantations of vanilla, on the western declivity of the Cordilleras in the State of Oaxaca, and in lesser quantity in those of Tabasco, Chiapas, and Yucatan. The eastern parts of Mexico exported in 1864, by way of Vera Cruz and Tampico, about 20,000 kilo. of vanilla, chiefly to Bordeaux. Since then the production seems to have much declined, the importation into France having been only 6,896 kilo. in 1871, and 1,938 in 1872.[2454]

The cultivation of vanilla in the small French colony of Réunion or Bourbon (40 miles long by 27 miles broad), introduced by Marchant in 1817 from Mauritius, has of late been very successful, notwithstanding many difficulties occasioned by the severe cyclones which sweep periodically over the island, and by microscopic fungi which greatly injured the plant. In 1849 the export of vanilla from Réunion was 3 kilogrammes, in 1877 it reached 30,973 kilogrammes. The neighbouring island of Mauritius also produces vanilla, of which it shipped in 1872 7,139 lbs., in 1877 the quantity was 20,481 lbs. There is likewise a very extensive cultivation of vanilla in Java.

Vanilla comes into the market chiefly by way of France, which country, according to the official statistics, imported in 1871, 29,914 kilo. (65,981 lbs.); in 1872, 26,587 (58,643 lbs.); in 1874 that quantity amounted to 34,906 kilo.

Uses—Vanilla has long ceased to be used in medicine, at least in this country, but is often sold by druggists for flavouring chocolate, ices, creams, and confectionery.

IRIDACEÆ.

RHIZOMA IRIDIS.

Radix Iridis Florentinæ; Orris Root; F. Racine d’Iris; G. Veilchenwurzel.

Botanical Origin—This drug is derived from three species of Iris, namely:—

1. Iris germanica L., a perennial plant with beautiful large deep blue flowers, common about Florence and Lucca, ascending to the region of the chestnut. It is also found dispersed throughout Central and Southern Europe, and in Northern India and Morocco; and is one of the commonest plants of the gardens round London, where it is known as the Blue Flag.

2. I. pallida Lam., a plant differing from the preceding by flowers of a delicate pale blue, growing wild in stony places in Istria. It is abundant about Florence and Lucca in the region of the olive, but is a doubtful native.

3. I. florentina L., closely allied to I. pallida, yet bearing large white flowers, is indigenous to the coast region of Macedonia and the south-western shores of the Black Sea, Hersek, in the Gulf of Ismid, and about Adalia in Asia Minor. It also occurs in the neighbourhood of Florence and Lucca, but in our opinion only as a naturalized plant.[2455]

These three species, but especially I. germanica and I. pallida, are cultivated for the production of orris root in the neighbourhood of Florence. They are planted on the edges of terraces and on waste, stony places contiguous to cultivated ground. I. florentina is seldom found beyond the precincts of villas, and is far less common than the other two.

History—In ancient Greece and Rome, orris root was largely used in perfumery; and Macedonia, Elis, and Corinth were famous for their unguents of iris.[2456] Theophrastus and Dioscorides were well acquainted with orris root; the latter, as well as Pliny, remarks that the best comes from Illyricum, the next from Macedonia, and a sort still inferior from Libya; and that the root is used as a perfume and medicine. Visiani[2457] considers that Iris germanica is the Illyrian iris of the ancients, which is highly probable, seeing that throughout Dalmatia (the ancient Illyricum) that species is plentiful, and I. florentina and I. pallida do not occur. At what period the two latter were introduced into Northern Italy we have no direct evidence, but it was probably in the early middle ages. The ancient arms of Florence, a white lily or iris on a red shield,[2458] seem to indicate that that city was famed for the growth of these plants. Petrus de Crescentiis[2459] of Bologna, who flourished in the 13th century, mentions the cultivation of the white as well as of the purple iris, and states at what season the root should be collected for medicinal use.

But the true Illyrian drug was held to be the best; and Valerius Cordus[2460] laments that it was being displaced by the Florentine, though it might easily be obtained through the Venetians.

Orris root mixed with anise was used in England as a perfume for linen as early as 1480 (p. 311), under which date it is mentioned in the Wardrobe Accounts of Edward IV.

All the species of iris we have named were in cultivation in England in the time of Gerarde,—that is, the latter end of the 16th century. The starch of the rhizome was formerly reckoned medicinal, and directions for its preparation are to be found in the Traicté de la Chymie of Le Febvre, i. (1660) 310.

Production—The above-mentioned species of iris are known to the Tuscan peasantry by the one name of Giaggiolo. The rhizomes are collected indiscriminately, the chief quantity being doubtless furnished by the two more plentiful species, I. germanica and I. pallida. They are dug up in August, are then peeled, trimmed, and laid out in the sunshine to dry, the larger bits cut off being reserved for replanting. At the establishment of Count Strozzi, founded in 1806 at Pontasieve near Florence, which lies in the midst of the orris district, the rhizomes, collected from the peasants by itinerant dealers, are separated into different qualities, as selected (scelti) and sorts (in sorte), and are ultimately offered in trade either entire, or in small bits (frantumi), parings (raspature), powder (polvere di giaggiolo o d’ ireos), or manufactured into orris peas.

The growing of orris is only a small branch of industry, the crops being a sort of side-product, but it is nevertheless shared between the tenant and landowner as is usual on the Tuscan System of husbandry.[2461]

In the mountainous neighbourhood of Verona, the rhizomes of Giglio celeste or Giglio selvatico, i.e., Iris germanica, are collected and chiefly brought to the small places of Tregnano and Illasi, north-east of Verona. The peasants distinguish the selected long roots (radice dritta), the knotty roots (radice groppo) which are used for the issue-peas, and the fragments (scarto) employed in perfumery.

Some orris root is also exported from Botzen in southern Tyrol.

Description.—The rootstock is fleshy, jointed and branching, creeping horizontally near the surface of the ground. It is formed in old plants of the annual joints of five or six successive years, the oldest of which are evidently in a state of decay. These joints are mostly dichotomous, subcylindrical, a little compressed vertically, gradually becoming obconical, and obtaining a maximum size when about three years old. They are 3 to 4 inches long and sometimes more than 2 inches thick. Those only of the current year emit leaves from their extremities. The rhizome is externally yellowish-brown, internally white and juicy, with an earthy smell and acrid taste. By drying, it gradually acquires its pleasant violet odour, but it is said not to attain its maximum of fragrance until it has been kept for two years.

We have carefully compared with each other the fresh rhizomes of the three species under notice, but are not able to point out any definite character for distinguishing them apart.

Dried orris root as found in the shops occurs in pieces of 2 to 4 inches long, and often as much as 1¼ inches wide. A full-sized piece is seen to consist of an elongated, irregularly subconical portion emitting at its broader end one or two (rarely three) branches which, having been cut short in the process of trimming, have the form of short, broad cones, attached by their apices to the parent rootstock. The rootstock is flattened, somewhat arched, often contorted, shrunken and furrowed. The lower side is marked with small circular scars, indicating the point of insertion of rootlets. The brown outer bark has been usually entirely removed by peeling and paring; and the dried rhizome is of a dull, opaque white, ponderous, firm and compact. It has an agreeable and delicate odour of violets, and a bitterish, rather aromatic taste, with subsequent acridity.

A sort of orris root which has been dried without the removal of the outer peel, is found under the name of Irisa in the Indian bazaars, and now and then in the London market. It is, we suppose, the produce of Iris germanica L. (I. nepalensis Wall.), which, according to Hooker, is cultivated in Kashmir. Orris root of rather low quality is now often imported from Morocco; it is obtained, we believe, exclusively from I. germanica.

Microscopic Structure—On transverse section, the white bark about 2 mm. broad, is seen to be separated by a fine brown line from the faintly yellowish woody tissue. The latter is traversed by numerous vascular bundles, in diffuse and irregular rings, and exhibits here and there small shining crystals of oxalate of calcium. It is made up uniformly of large thick-walled spherical porous cells, loaded with starch granules, which are oval, rather large and very numerous; prisms of calcium oxalate are also visible. The latter were noticed already by one of the earliest microscopic observers, Anton van Leeuwenhoek, about the year 1716. The spiral vessels are small and run in very various directions. The foregoing description is applicable to any one of the three species we have named.

Chemical Composition—When orris root is distilled with water, a crystalline substance, called Orris Camphor, is found floating on the aqueous distillate. This substance, which we first obtained from the laboratory of Messrs. Herrings & Co. of London, is yielded, as we learn from Mr. Umney, to the extent of 0·12 per cent.—that is to say, 3 cwt. 3 qrs. 23 lb. of rhizome afforded of it 8½ ounces.[2462] Messrs. Schimmel & Co. of Leipzig also presented us with the same substance, of which they obtain usually 0·60 to 0·80 per cent. Orris camphor has the exquisite and persistent fragrance of the drug; we have proved[2463] that this presumed stearoptene or camphor of orris root consists of myristic acid, C₁₄H₂₈O₂ (see page 508), impregnated with the minute quantity of essential oil occurring in the drug. The oil itself would appear not to pre-exist in the living root, but to be formed on drying it.

By exhausting orris root with spirit of wine, a soft brownish resin is obtained, together with a little tannic matter. The resin has a slightly acrid taste; the tannin strikes a green colour with persalts of iron.

Commerce—Orris root is shipped from Leghorn, Trieste and Mogador,—from the last named port to the extent in 1876 of 834 cwt.[2464] There are no data to show the total imports into Great Britain. France imported in the year 1870 about 50 tons of orris root.

Uses—Frequently employed as an ingredient in tooth-powders, and in France for making issue-peas; but the chief application is as a perfume.

CROCUS.

Croci stigmata; Saffron[2465]; F. and G. Saffran.

Botanical Origin—Crocus sativus L., a small plant with a fleshy bulb-like corm and grassy leaves, much resembling the common Spring Crocus of the gardens, but blossoming in the autumn. It has an elegant purple flower, with a large orange-red stigma, the three pendulous divisions of which are protruded beyond the perianth.

The Saffron Crocus is supposed to be indigenous to Greece, Asia Minor, and perhaps Persia, but it has been so long under cultivation in the East that its primitive home is somewhat doubtful.[2466]

History—Saffron, either as a medicine, condiment, perfume, or dye, has been highly prized by mankind from a remote period, and has played an important part in the history of commerce.

Under the Hebrew name Carcôm, which is supposed to be the root of the word Crocus, the plant is alluded to by Solomon;[2467] and as Κρόκος, by Homer, Hippocrates, Theophrastus, and Theocritus. Virgil and Columella mention the saffron of Mount Tmolus; the latter also names that of Corycus in Cilicia, and of Sicily, both which localities are alluded to as celebrated for the drug by Dioscorides and Pliny.

Saffron was an article of traffic on the Red Sea in the first century; and the author of the Periplus remarks that Κρόκος is exported from Egypt to Southern Arabia, and from Barygaza in the gulf of Cambay.[2468] It was well known under the name kunkuma to the earlier Hindu writers.

It was cultivated at Derbend and Ispahan in Persia, and in Transoxania in the 10th century,[2469] whence it is not improbable the plant was carried to China, for according to the Chinese it came thither from the country of the Mahomedans. Chinese writers have recorded that under the Yuen dynasty (.d. 1280-1368), it became the custom to mix Sa-fa-lang (Saffron) with food.[2470]

There is evidence to show that saffron was a cultivated production of Spain[2471] as early as a.d. 961; yet it is not so mentioned, but only as an eastern drug, by St. Isidore, archbishop of Seville in the 7th century. As to France, Italy, and Germany, it is commonly said that the saffron crocus was introduced into these countries by the Crusaders. Porchaires, a French nobleman, is stated to have brought some bulbs to Avignon towards the end of the 14th century, and to have commenced the cultivation in the Comtat Venaissin, where it existed down to recent times. About the same time, the growing of saffron is said to have been introduced by the same person into the district of Gâtinais, south of Paris.[2472] At that period, saffron was one of the productions of Cyprus,[2473] with which island France was then, through the princes of Lusignan, particularly related.

During the middle ages, the saffron cultivated at San Gemignano in Tuscany was an important article of exportation to Genoa.[2474] That of Aquila in the Abruzzi was also famous, and used to be distinguished in price-lists till the beginning of the present century; the culture of saffron is still going on there to a small extent.[2475] The growing of saffron in Sicily, which was noticed even by Columella, is carried on to the present day, but the quantity produced is insufficient even for home consumption.[2476] In Germany and Switzerland, where a more rigorous climate must have increased the difficulties of cultivation, the production of saffron was an object of industry in many localities.[2477]

The saffron crocus is said to have been introduced into England during the reign of Edward III. (a.d. 1327-1377).[2478] Two centuries later English saffron was even exported to the Continent, for in a priced list of the spices sold by the apothecaries of the north of France, a.d. 1565-70, mention is made of three sorts of saffron, of which “Safren d’Engleterre” is the most valuable.[2479] It was evidently produced in considerable quantities, for in 1682 we find in the tariff of the “Apotheke” of Celle, Hanover, crocus austriacus optimus, and Crocus communis anglicus.[2480]

In the beginning of the last century (1723-28), the cultivation of saffron was carried on in what is described by a contemporary writer[2481] as—“all that large tract of ground that lies between Saffron Walden and Cambridge, in a circle of about 10 miles diameter.” The same writer remarks that saffron was formerly grown in several other counties of England. The cultivation of the crocus about Saffron Walden, which was in full activity when Norden[2482] wrote in 1594, had ceased in 1768, and about Cambridge at nearly the same time.[2483] Yet the culture must have lingered in a few localities, for in the early part of the present century a little English saffron was still brought every year from Cambridgeshire to London, and sold as a choice drug to those who were willing to pay a high price for it.

Saffron was employed in ancient times to a far greater extent than at the present day. It entered into all sorts of medicines, both internal and external; and it was in common use as a colouring and flavouring ingredient of various dishes for the table,. The drug, from its inevitable costliness, has been liable to sophistication from the earliest times. Both Dioscorides and Pliny refer to the frauds practised on it, the latter remarking—“adulteratur nihil æquè.”

During the middle ages the severest enactments were not only made, but were actually carried into effect, against those who were guilty of sophisticating saffron, or even of possessing the article in an adulterated state. Thus at Pisa, in a.d. 1305, the fundacarii, or keepers of the public warehouses, were required by oath and heavy penalties to denounce the owners of any falsified saffron consigned to their custody.[2484] The Pepperers of London about the same period were also held responsible to check dishonest tampering with saffron.[2485]

In France, an edict of Henry II., of 18th March, 1550, recites the advantages derived from the cultivation of saffron in many parts of the kingdom, and enacts the confiscation and burning of the drug when falsified, and corporal punishment of offenders.[2486]

The authorities in Germany were far more severe. A Safranschau (Saffron inspection) was established at Nuremberg in 1441, in which year 13 lb. of saffron was publicly burnt at the Schönen Brunnen in that city. In 1444, Jobst Findeker was burnt together with his adulterated saffron! And in 1456, Hans Kölbele, Lienhart Frey, and a woman, implicated in falsifying saffron, were buried alive. The Safranschau was still in vigour as late as 1591: but new regulations for the inspection of saffron were passed in 1613.[2487] There was also in the same city a Gewürzschau, or Spice-inspection, from 1441 to 1797. Similar inspections were established in most German towns during the middle ages.

Description—The flower of the saffron crocus has a style 3 to 4 inches long, which in its lower portion is colourless, and included within the tube of the perianth. In its upper part it becomes yellow, and divides into three tubular, filiform, orange-red stigmas, each about an inch in length. The stigmas expand towards their ends, and the tube of which they consist is toothed at the edge and slit on its inner side. The stigma is the only part officinal, and alone is rich in colouring matter.

Commercial saffron (Hay Saffron of the druggists) is a loose mass of thread-like stigmas, which when unbroken are united in threes at the upper extremity of the yellow style. It is unctuous to the touch, tough and flexible; of a deep orange-red, peculiar aromatic smell, and bitter and rather pungent taste. It is hygroscopic and not easily pulverized; it loses by drying at 100° C. about 12 per cent. of moisture, which it quickly reabsorbs.[2488]

The colouring power of saffron is very remarkable: we have found that a single grain rubbed to fine powder with a little sugar will impart a distinct tint of yellow to 700,000 grains (10 gallons) of water.

Microscopic Structure—The tissue of the stigma consists of very thin, sinuous, closely-felted, thread-shaped cells, and small spiral vessels. The yellow colouring matter penetrates the whole, and is partly deposited in granules. The microscope likewise exhibits oil-drops, and small lumps, probably of a solid fat. Large isolated pollen grains are also present.

Chemical Composition—The splendid colouring matter of saffron has long been known as Polychroit; but in 1851 Quadrat, who instituted some fresh researches on the drug, gave it the name of Crocin, which was also adopted in 1858 by Rochleder. Weiss in 1867[2489] has shown that it is a glucoside, for which he retains the name of Polychroit, while the new colouring matter which results from its decomposition he terms Crocin. It agrees with the Crocetin of Rochleder.

Polychroit was prepared by Weiss in the following manner: saffron was treated with ether, by which fat, wax, and essential oil were removed; and it was then exhausted with water. From the aqueous solution, gummy matters and some inorganic salts were precipitated by strong alcohol. After the separation of these substances, polychroit was precipitated by addition of ether. Thus obtained, it is an orange-red, viscid, deliquescent substance, which, dried over sulphuric acid, becomes brittle and of a fine ruby colour. It has a sweetish taste, but is devoid of odour, readily soluble in spirit of wine or water, and sparingly in absolute alcohol. By dilute acids, it is decomposed into Crocin, sugar, and an aromatic volatile oil having the smell of saffron. Weiss gives the following formula for this decomposition:—

C₄₈H₆₀O₁₈ + H₂O = 2(C₁₆H₁₈O₆) · C₁₀H₁₄O · C₆H₁₂O₆.

polychroit crocin essential oil sugar

Crocin is a red powder, insoluble in ether, easily soluble in alcohol, and precipitable from this solution on addition of ether. It is only slightly soluble in water, but freely in an alkaline solution, from which an acid precipitates it in purple-red flecks. Strong sulphuric and nitric acids occasion the same colours as with polychroit; the former producing deep blue, changing to violet and brown, and the latter green, yellow, and finally brown. It is remarkable that hydrocarbons of the benzol class do not dissolve the colouring matter of saffron.

The oil obtained by decomposing crocin is heavier than water; it boils at about 209° C., and is easily altered,—even by water. It is probably identical with the volatile oil obtainable to the extent of one per cent. from the drug itself, and to which its odour is due.

Saffron contains sugar (glucose?), besides that obtained by the decomposition of polychroit. The drug leaves after incineration 5 to 6 per cent. of ash.

Production and Commerce—In France the cultivation is carried on by small peasant proprietors; the flowers are collected at the end of September or in the beginning of October. The stigmas are quickly taken out, and immediately dried on sieves over a gentle fire, to which they are exposed for only half an hour. According to Dumesnil[2490] 7,000 to 8,000 flowers are required for yielding 500 grammes (17½ oz.) of fresh saffron, which by drying is reduced to 100 grammes.

Notwithstanding the high price of saffron, its cultivation is by no means always profitable, from the many difficulties by which it is attended. Besides occasional injury from weather, the bulbs are often damaged by parasitic fungi as stated by Duhamel in 1728[2491] and again by Montagne in 1848.[2492]

The most considerable quantity of saffron is now produced in Spain, namely in Lower Arragon, in Novelda near Alicante, in the province Albacete (Northern Murcia), in La Mancha, near Huelva, and also near Palma in the island of Mallorca. It is brought into commerce as Alicante and Valencia Saffron. The quantity of saffron exported from Spain in 1864 was valued at £190,062; in 1865, £135,316; in 1866, £47,083. The drug was chiefly exported to France.[2493]

French saffron, which enjoys a better reputation for purity than the Spanish, is cultivated in the arrondissement of Pithiviers-en-Gâtinais, in the department of the Loiret, which district annually furnishes a quantity valued at 1,500,000 (£60,000) to 1,800,000 francs.[2494] The exports of France in 1875 were 97,021 kilogrammes, 84,337 of which being imported from Spain.

In Austria, Maissau, north-east of Krems on the Danube, still produces excellent saffron, though only to a very small extent; the district was formerly celebrated for the drug. Saffron is produced in considerable quantity in Ghayn, an elevated mountain region separating Western Afghanistan from Persia.[2495] A very little of inferior quality is collected at Pampur in Kashmír, under heavy imposts of the Maharaja.[2496] Saffron is also cultivated in some districts of China. Finally, the cultivation has been introduced into the United States, and a little saffron is collected by the German inhabitants of Lancaster County, Pennsylvania.[2497] But in almost all countries the cultivation of saffron is on the decline, and in very many districts has altogether ceased.

The imports of saffron into the United Kingdom amounted in 1870 to 43,950 lb., valued at £95,690. The article is largely exported to India, but there are no general statistics to show the amount. Bombay imported in the year 1872-73, 21,994 lb., value £35,115.[2498] It is a curious fact that now Spanish saffron finds regularly its way to India.

Uses—Saffron is of no value for any medicinal effects, and retains a place in the pharmacopœia solely on the ground of its utility as a colouring agent. A peculiar preference for it as a condiment exists in various countries, but especially in Austria, Germany and some districts of Switzerland. This predilection prevails even in England—at least in Cornwall, where the use of saffron for colouring cakes is still common. Saffron is largely used by the natives of India in religious rites, in medicine and for the colouring and flavouring of food.

As a dye-stuff saffron is no longer employed, at least in this country, its use having been superseded by less costly substances.

Adulteration—Saffron is often adulterated, but the frauds practised on it are not difficult of detection. Sometimes the falsification consists in the addition of florets of Calendula dyed with logwood, or of safflower, or the stamens of the saffron crocus, any of which may be detected if a small pinch of the drug be dropped on the surface of warm water, when the peculiar form of the saffron stigma will at once become evident.

Another adulteration of late much practised, and not always easy to detect by the eye, consists in coating genuine saffron with carbonate of lime, previously tinged orange-red. If a few shreds of such saffron be placed on the surface of water in a wineglass and gently stirred, the water will immediately become turbid, and the carbonate of lime will detach itself as a white powder and subside. Saffron thus adulterated will freely effervesce when dilute hydrochloric acid is dropped upon it. We have examined Alicante Saffron, the weight of which had been increased more than 20 per cent. by this fraudulent admixture. The earthy matter employed in sophisticating saffron is said to be sometimes emery powder, rendered adherent by honey. We have found that adulterated with carbonate of lime to leave from 12 to 28 per cent. of ash.[2499]

PALMÆ.

SEMEN ARECÆ.

Nuces Arecæ vel Betel; Areca Nuts, Betel Nuts; F. Semence ou Noix d’Arec; G. Arekanüsse, Betelnüsse.

Botanical Origin—Areca Catechu L., a most elegant palm,[2500] with a straight smooth trunk, 40 to 50 feet high and about 20 inches in circumference. The inflorescence is arranged on a branching spadix, with the male flowers on its upper portion and the female near its base. The tree is cultivated in the Malayan Archipelago, the warmer parts of the Indian Peninsula, Ceylon, Indo-China and the Phillippines. It is probably indigenous to the first-named region.

History—The Areca palm is mentioned in the Sanskrit writings as Guvāca. It is called in Chinese Pin-lang, a name apparently derived from Pinang, a designation for the tree in the Malay Islands, whence the Chinese anciently derived their supply of the seeds. The oldest Chinese work to mention the pin-lang is the San-fu-huang-tu, a description of Chang-an, the capital of the Emperor Wu-ti, b.c. 140-86. It is there stated that after the conquest of Yunnan, b.c. 111, some remarkable trees and plants of the south were taken to the capital, and among them more than 100 pin-lang, which were planted in the imperial gardens. Bretschneider,[2501] to whose researches we are indebted for this information, cites several other Chinese works, from the first century downwards, showing that areca nuts were brought from the then unsubdued provinces of Southern China, the Malayan Archipelago and India. The custom of presenting areca nut to a guest is alluded to in a work of the 4th century.

The Arabian writers, as for instance Ibn Batuta, were well acquainted with the areca nut, which they called Fófal, and with the Indian custom of masticating it with lime.

Areca nut, though held in great estimation among Asiatics as a masticatory, and supposed to strengthen the gums, sweeten the breath and improve digestion, has not until recently been regarded as possessing any particular medicinal powers beyond those of a mild astringent.[2502] It has often been administered as a vermifuge to dogs, and in India and China is given with the same intent to the human subject. Some successful trials recently made of it for the expulsion of tapeworm have led to it being included in the Additions to the British Pharmacopœia of 1867, published in 1874.

Description—The areca palm produces a smooth ovoid fruit, of the size of a small hen’s egg, slightly pointed at its upper end, and crowned with the remains of the stigmas. Its exterior consists of a thick pericarp, at first fleshy, but, when quite mature, composed of fine stringy fibres running lengthwise, with much coarser ones below them. This fibrous coat is consolidated into a thin crustaceous shell or endocarp, which surrounds the solitary seed. The latter has the shape of a very short rounded cone, scarcely an inch in height; it is depressed at the centre of the base, and has frequently a tuft of fibres on one side of the depression, indicating its connexion with the pericarp. The testa, which seems to be partially adherent to the endocarp, is obscurely defined, and inseparable from the nucleus. Its surface is conspicuously marked with a network of veins, running chiefly from the hilum. When a seed is split open, it is seen that these veins extend downwards into the white albumen, reaching almost to its centre, thus giving the seed a strong resemblance both in structure and appearance to a nutmeg. The embryo, which is small and conical, is seated at the base of the seed. Areca nuts are dense and ponderous, and very difficult to break or cut. They have when freshly broken a weak cheesy odour, and taste slightly astringent.

Microscopic Structure—The white horny albumen is made up of large thick-walled cells, loaded with an albuminoid matter, which on addition of iodine assumes a brown hue. The cell-walls display large pores, the structure of which, after boiling in caustic ley, becomes clearly evident in polarized light. The brown tissue which runs into the albumen is of loose texture, and resembles the corresponding structure in a nutmeg. The thin walls of its cells are marked with fine spiral striations, and in this tissue, as well as on the brown surface of the seed, delicate spiral vessels are scattered. All the brown cells assume a rich red if moistened with caustic ley, and a dingy green with ferric chloride.

Chemical Composition—We have exhausted the powder of the seeds, previously dried at 100° C., with ether; and thereby obtained a colourless solution, which after evaporation left an oily liquid, concreting on cooling. This fatty matter, representing 14 per cent. of the seed, was thoroughly crystalline and melted at 39° C. By saponification we obtained from it a crystalline fatty acid fusing at 41° C., which may consequently be a mixture of lauric and myristic acids. Some of the fatty matter was boiled with water: the water on evaporation afforded an extremely small trace of tannin but no crystals, which had catechin been present should have been left.

The powdered seeds which had been treated with ether were then exhausted by cold spirit of wine (·832), which afforded 14·77 per cent. (reckoned on the original seeds) of a red amorphous tannic matter, which after drying, proved to be but little soluble in water, whether cold or boiling. Submitting to destructive distillation, it afforded Pyrocatechin. Its aqueous solution is not altered by ferrous sulphate, unless an alkali is added, when it assumes a violet hue, with separation of a copious dark purplish precipitate. On addition of a ferric salt in minute quantity to the aqueous solution of the tannic matter, a fine green tint is produced, quickly turning brown by a further addition of the test, and violet by an alkali. An abundant dark precipitate is also formed.

The seeds having been exhausted by both ether and spirit of wine, were treated with water, which removed from them chiefly mucilage precipitable by alcohol. The alcohol thus used afforded on filtration traces of an acid, the examination of which was not pursued. After exhaustion with ether, spirit of wine and water, a dark brown solution is got by digesting the residue in ammonia: from this solution, an acid throws down an abundant brown precipitate, not soluble even in boiling alcohol. We have not been able to obtain crystals from an aqueous decoction of the seeds, nor by exhausting them directly with boiling spirit of wine. We have come therefore to the conclusion that Catechin (p. 243) is not a constituent of areca nuts, and that any extract, if ever made from them, must be essentially different to the Catechu of Acacia or of Nauclea, and rather to be considered a kind of tannic matter of the nature of Ratanhia-red or Cinchona-red.

By incinerating the powdered seeds, 2·26 per cent. were obtained of a brown ash, which, besides peroxide of iron, contained phosphate of magnesium.

Commerce—Areca nuts are sold in India both in the husk (pericarp) and without it, and the two sorts are enumerated in the Customs Returns under distinct heads. Their widespread consumption in the East gives rise to an enormous trade, of which some notion may be formed by a consideration of the few statistics bearing upon it which are accessible.

Thus, Ceylon exported of areca nuts in the year 1871, 66,543 cwt., value £62,593; in 1872, 71,715 cwt.,—the latter quantity entirely to India; in 1875 of the total export of 94,567 cwt. 86,446 were shipped to India.[2503]

The Madras Presidency largely trades in the same commodity. In the year 1872-1873 there were shipped thence to Bombay 43,958 cwt., besides about two millions of the entire fruit.[2504] An extensive traffic in areca nuts is carried on at Singapore and especially in Sumatra.

Uses—Powdered areca nut may be given for the expulsion of tapeworm in the dose of 4 to 6 drachms, taken in milk. The remedy should be administered to the patient after a fast of about twelve hours; some recommend the previous exhibition of a purgative. It is said to be efficacious against lumbricus as well as tænia.

The charcoal afforded by burning areca nuts in a close vessel is sold as a tooth powder; but except greater density, it possesses no advantage over the charcoal from ordinary wood.

As a masticatory areca nut is chewed with a little lime and a leaf of the Betel Pepper, Piper Betle L. The nut for this purpose is used in a young and tender state, or is prepared by boiling in water; it is sometimes combined with aromatics, as camphor or cardamom.

SANGUIS DRACONIS.

Resina Draconis; Dragons Blood; F. Sang-dragon; G. Drachenblut.

Botanical Origin—Calamus Draco[2505] Willd. (Dæmonorhops Draco Mart.)—This is one of the Rotang or Rattan Palms, remarkable for their very long flexible stems, which climb among the branches of trees by means of spines on the leafstalk. The species under notice, called in Malay Rotang Jernang, grows in swampy forests of the Residency of Palembang and in the territory of Jambi, in Eastern Sumatra, and in Southern Borneo, which regions furnish the dragon’s blood of commerce. It is said to occur also in Penang and in various islands of the Sunda chain.

History—The substance which is mentioned by Dioscorides under the name of Κιννάβαρι, as a costly pigment and medicine brought from Africa, and which is also described by Pliny who distinguished it from minium, was certainly the resin called Dragon’s Blood. It was not however that of the Rotang Palm, Calamus Draco, or even of any tree of the Indian Archipelago, but was on the contrary a production of the island of Socotra (see p. 675).

Dragon’s blood is, we believe, not named by any of the earlier voyagers to the India islands. Ibn Batuta, who visited both Java and Sumatra between a.d. 1325 and 1349, and notices their producing benzoin (see p. 404), cloves, camphor, and aloes-wood, is silent about dragon’s blood. Barbosa, whose intelligent narrative (a.d. 1514) of the East Indies[2506] is full of reference to the trade and productions of the different localities he visited, states that aloes and dragon’s blood are produced in Socotra, but makes no mention of the latter commodity as found at Malacca, Java, Sumatra, or Borneo.

The fact we wish to prove is corroborated by the accounts of early commercial intercourse between the Chinese and Arabs recently published by Bretschneider.[2507] From the 10th to the 15th century there was carried on between these nations a trade, the objects of which were not only the productions of the Arabian Gulf and countries further north, but also those of the Indian Archipelago. One of the islands with which the Arabs and Persians carried on a great commerce was Sumatra, whence they obtained the precious camphor so much valued by the Chinese, but not, so far as it appears, the resin dragon’s blood. As to the productions brought from Arabia they are enumerated as Ostriches, Olibanum, Liquid Storax, Myrrh, and Dragon’s Blood, besides a few other articles not yet determined. It is worthy of remark that the Chinese are still the principal consumers of dragon’s blood, though like the rest of mankind they have to content themselves with the plentiful drug of Sumatra and Borneo, instead of the more ancient sort produced in Socotra.

The first clear account of the production of the resin in India is that given by Rumphius, who in his Herbarium Amboinense[2508] describes the process by which it is collected at Palembang.

Production—The fruit of Calamus Draco, which is produced in panicles in great profusion, is globose and of the size of a large cherry, clothed with smoothed downward-overlapping scales. These scales are sub-quadrangular, thick and shell-like, marked with a longitudinal furrow; the largest, which are found towards the middle of the fruit, are 2 lines long by 3 broad. At maturity the fruit is covered with an exudation of red resin, which encrusts it so abundantly that the form of the scales can hardly be seen.

The resin, which is naturally friable, is collected by gathering the fruits, and shaking or beating them in a sack, by which process it is soon separated. It is then sifted to remove from it scales and other portions of the fruit. By exposure to the heat of the sun or in a covered vessel to that of boiling water, the resin is so far softened that it can be moulded into sticks or balls, which are forthwith wrapped in a piece of palm leaf. It is thus that the best dragon’s blood, or jernang, is obtained. An inferior quality is got by boiling the pounded fruits in water, and making the resin into a mass, frequently with the addition of other substances by way of adulteration. The foregoing is the account of the manufacture of the drug given by Blume.[2509]

Description—Dragon’s Blood is found in commerce chiefly in two forms, known respectively as Reed and Lump.

1. Reed Dragon’s Blood (Dragon’s Blood in sticks, Sanguis draconis in baculis). Some of fine quality purchased in London in 1842 is in sticks 13 to 14 inches in length, and ¾ to 1 inch in diameter, neatly wrapped in palm leaf, secured by 8 or 9 transverse bands of some flexible grass. The average weight of each stick, including the enveloping leaf, is five ounces. The resin has evidently been wrapt up while soft, as the sticks are furrowed longitudinally by pressure of the surrounding leaf. The smooth surface is of an intense blackish-brown; when seen in thin splinters the resin appears transparent, and of a pure and brilliant crimson. The fractured surface looks resinous and rough, is a little porous, and contains numerous particles of the scales of the fruit. Rubbed on paper it leaves a red mark of not very splendid tint. Heated with alcohol it left 20 per cent. of pulverulent residue consisting chiefly of vegetable matter. Sticks of smaller size are more common.

2. Lump Dragon’s Blood (Sanguis draconis in massis) is imported in large rectangular blocks or irregular masses. From the fine Reed Dragon’s Blood, just described, it differs in containing a larger proportion of remains of the fruit, including numerous entire scales. Hence it has a coarser fracture, and the fractured surface is less intense in tint. Its taste is slightly acrid. Exhausted with alcohol it leaves a residue amounting in the specimen we tested to 27 per cent.

Dragon’s blood is abundantly soluble in the usual solvents of resins, namely, the alcohols (even in dilute spirit of wine), benzol, chloroform, bisulphide of carbon, and the oxygenated essential oils, as that of cloves. The residue left after the evaporation of these liquids is amorphous and of the original fine red colour. The drug is likewise dissolved by glacial acetic acid as well as by caustic soda; the latter solution on addition of an excess of acid yields a dingy brown, jelly-like precipitate, which on drying turns dark red like the original drug. In ether dragon’s blood is sparingly soluble, and still less so in oil of turpentine; but in the most volatile portions of petroleum, the so-called petroleum ether we find it to be entirely insoluble. It has a slightly sweetish and somewhat acrid taste; melts at about 120° C., evolving the aromatic but irritating fumes of benzoic acid; boiled with water the resin becomes soft and partially liquid.

Chemical Composition—Dragon’s blood is a peculiar resin, which according to Johnston[2510] answers to the formula C₂₀H₂₀O₄. By heating it and condensing the vapour an aqueous acid liquid is obtained, together with a heavy oily portion of a pungent burning taste and crystals of benzoic acid. The composition of these products has not yet been thoroughly ascertained, but the presence of acetone, Toluol, C₆H₅(CH₃), Dracyl of Glénard and Boudault (1844), and Styrol, C₈H₈ (Draconyl), has been pointed out,[2511] the latter perhaps due to the existence in the drug of metastyrol (p. 274), as suggested by Kovalewsky.[2512] Both these hydrocarbons are lighter than water; yet we find that the above oily portion yielded by dry distillation sinks in water, a circumstance possibly occasioned by the presence of benzoic alcohol, C₆H₅(CH₂OH).

As benzoic acid is freely soluble in petroleum ether it ought to be removed from the drug by that solvent: on making the experiment we got traces of an amorphous red matter, a little of an oily liquid, but nothing crystalline. Cinnamic acid, on the other hand, is always present, according to Hirschsohn (1877). As to the watery liquid, it assumes a blue colour on addition of perchloride of iron, whence it would appear to contain phenol or pyrogallol rather than pyrocatechin (p. 196).

By boiling dragon’s blood with nitric acid, benzoic, nitro-benzoic, and oxalic acids are chiefly obtained, and only very little picric acid. Hlasiwetz and Barth melted the drug with caustic potash, and found among the products thus formed phloroglucin (p. 243), para-oxybenzoic, protocatechuic, and oxalic acids, as well as several acids of the fatty series. Benzoin yields similar products.

Commerce—Dragon’s blood is shipped from Singapore and Batavia. Large quantities are annually exported from Banjarmasin in Borneo to these places and to China.[2513]

Uses—In medicine, only as the colouring agent of plasters and tooth powders; in the arts, for varnish.

Adulteration—Dragon’s blood varies exceedingly in quality,[2514] of which the principal criterion regarded by the dealers is colour. Some of the inferior sorts make only a dull brick-red mark when rubbed on paper, and have an earthy-looking fracture. The sticks moreover do not take the impression of the enveloping leaf as when they are more purely resinous. A sample of inferior Reed Dragon’s Blood afforded us 40 per cent. of matter, insoluble in spirit of wine.

Other sorts of Dragon’s Blood.

Dragon’s Blood of Socotra—We have already stated (p. 672) that the Cinnabar mentioned by Dioscorides was brought from Africa. That the term really designated dragon’s blood seems evident from the fact that the author of the Periplus of the Erythrean Sea,[2515] written circa a.d. 54-68, names it (Κιννάβαρι) as a production of the island of Dioscorida, the ancient name of Socotra.

The Arabians, as Abu Hanifa and Ibn Baytar,[2516] describe dragon’s blood as brought from Socotra, giving to the drug the very name by which it is known to the Arabs at the present day, namely, Dam-ul-akh-wain. Barbosa (1514) as well as Giovanni di Barros[2517] mention it as a production of the island; and in our own times it has been noticed by Wellstead,[2518] Vaughan,[2519] and A. von Kremer.[2520] It is now but little collected. Vaughan states, as well as Von Wrede, that the tree is found in Hadramaut and on the east coast of Africa. The latter statement is also made in letters (1877, 1878), with which we were favoured by Captain Hunter of Aden and Hildebrandt of Berlin (see pages 140 and 141), by the latter of whom we were presented with a photographic sketch of the tree growing in the Somali country, at elevations of from 2500 to 5500 feet, and called there Moli. It is Dracæna schizantha Baker,[2521] a tree attaining 8 metres in height. The resin has an acidulous taste, and is, according to Hildebrandt, not exported, but occasionally eaten by the Somalis. The tree from which dragon’s blood is collected in Socotra is, according to Capt. Hunter, Dracæna Ombet Kotschy.

The Drop Dragon’s Blood, of which small parcels imported from Bombay or Zanzibar occasionally appear in the London market, is however this drug. It is in small tears and fragments, seldom exceeding an inch in length, has a clean glassy fracture, and in thin pieces is transparent and of a splendid ruby colour. From Sumatran dragon’s blood it may be distinguished by not containing the little shell-like scales constantly present in that drug, and by not evolving when heated on the point of a knife the irritating fumes of benzoic acid.

Dragon’s Blood of the Canary Islands—This substance is afforded by Dracæna Draco L., a liliaceous tree[2522] resembling a Yucca, of which the famous specimen at Orotava in Teneriffe has often been described on account of its gigantic dimensions and venerable age.[2523]

On the exploration of Madeira and Porto Santo in the 15th century, dragon’s blood was one of the valued productions collected by the voyagers, and is named as such by Alvise da ca da Mosto in 1454.[2524] It is also mentioned by the German physician Hieronymus Münzer, who visited Lisbon about 1494.[2525]

The tree yields the resin after incisions are made in its stem; but so far as we know the exudation has never formed a regular and ordinary article of commerce with Europe. It has been found in the sepulchral caves of the aboriginal inhabitants.

The name Dragon’s Blood has also been applied to an exudation obtained from the West Indian Pterocarpus Draco L., and to that of Croton Draco Schlecht.; but the latter appears to be of the nature of kino, and neither substance is met with in European commerce.

AROIDEÆ.

RHIZOMA CALAMI AROMATICI.

Radix Calami aromatici, Radix Acori; Sweet Flag Root; F. Acore odorant ou vrai, Roseau aromatique; G. Kalmus.

Botanical Origin—Acorus Calamus L., an aromatic, flag-like plant, growing on the margins of streams, swamps, and lakes, from the coasts of the Black Sea, through Southern Siberia, Central Asia, and India, as far as Amurland, Northern China, and Japan; indigenous also to North America. It is now established as a wild plant in the greater part of Europe, reaching from Sicily as far north as Scotland, Scandinavia, and Northern Russia; and is cultivated to a small extent in Burma and Ceylon.

Regarding the introduction of Acorus Calamus into Western Europe, it is believed in Poland to have been introduced there in the 13th century by the Tartars, yet it seems not to have attracted then any attention. The well-informed botanist, Bock (Tragus), mentioning the use of the preserved rhizome by wealthy persons, states[2526] that he had never seen the plant growing in Germany. Clusius[2527] relates that he first received a living plant in 1574, sent from the lake Apollonia near Brussa in Asia Minor. Camerarius,[2528] writing in 1588, speaks of it as introduced some years previously, and then plentiful in Germany, which seems to show a rapid propagation. Gerarde at the close of the century looked upon Acorus as an Eastern plant, which he says is grown in many English gardens, and might hence be fitly called the “Sweet Garden Flag.” Berlu,[2529] in 1724, observes of the root that—“it is brought in quantities from Germany:” hence we may infer that it was not then collected in England, as we know it was at a later period.[2530]

History—Sweet Flag root has been from the earliest times a favourite medicine of the natives of India, in which country it is sold in every bazaar. Ainslie[2531] asserts that it is reckoned so valuable in the bowel complaints of children that there is a penalty incurred by any druggist who will not open his door in the middle of the night to sell it, if demanded!

The descriptions of Acoron, a plant of Colchis, Galatia, Pontus, and Crete, given by Dioscorides and Pliny, certainly refer to this drug. We think that the Κάλαμος ἀρωματικός of Dioscorides, which he states to grow in India, is the same, though Royle regards it as an Andropogon. The Κάλαμος of Theophrastus and the Calamus of the English Bible[2532] are considered by some authors to refer to the Sweet Flag.

Celsus in the first century mentioned Calamus Alexandrinus, the drug being probably then brought from India by way of the Red Sea. We know by the testimony of Amatus Lusitanus[2533] that in the 16th century it used to be so imported into Venice. Rheede,[2534] moreover, described and figured Acorus Calamus as an Indian plant under the name Vacha, which it still bears on the Malabar Coast. But in the pharmaceutical tariff of the German town of Halberstadt of the year 1697, “Calamus aromaticus verus, Indianischer Calmus” and “Calamus aromaticus nostras,” common Calmus, are quoted at exactly the same price,[2535] and Murray[2536] states expressly that in his time (1790) Asiatic calamus was still met with in the pharmacies of Continental Europe, but that it had mostly been replaced by the home-grown drug. At the present time the Calamus aromaticus of commerce is European; in all essential characters it agrees with that of India, a package of which is now and then offered in the London drug sales.

Collection—The London market is supplied from Germany, whither the drug is brought, we believe, from Southern Russia. It is no longer collected in England,—at least in quantity, though it used to be gathered some years ago in Norfolk.

Description—The rootstock of sweet flag occurs in somewhat tortuous, subcylindrical or flattened pieces, a few inches long, and from ½ to 1 inch in greatest diameter. Each piece is obscurely marked on the upper surface with the scars, often hairy, of leaves, and on the under with a zigzag line of little, elevated, dot-like rings,—the scars of roots. The rootstock is usually rough and shrunken, varying in colour from dark brown to orange-brown, breaking easily with a short corky fracture, and exhibiting a pale brown spongy interior. The odour is aromatic and agreeable; the taste, bitterish and pungent.

The fresh rootstock is brownish-red or greenish, white or reddish within, and of a spongy texture. Its transverse section is tolerably uniform; a fine line (medullary sheath) separates the outer tissue from the lighter central part, the diameter of which is twice or three times the width of the former.

Microscopic Structure—The outermost layer is made up of extended epiblema-cells or of a brown corky tissue, the latter occurring in the parts free from leaf-scars. The prevailing tissue, both of the outer and the central part, consists of uniform nearly globular cells, traversed by numerous vascular bundles, especially at the boundary line (medullary sheath). Besides them, the rootstock like that of many fresh-water plants, exhibits a large number of intercellular holes. These air-holes, or more correctly water-holes, are somewhat longitudinally extended, so as to form a kind of network, imparting a spongy consistence[2537] to the fresh rootstock. At certain places, where the series of cells cross one another, especially in the outer part, there are single cells filled with essential oil,[2538] which may be made very conspicuous by adding to sections dilute potash or perchloride of iron. The other cells are loaded with small starch granules; a little mucilage and tannic matter is met with in the exterior coat.

Chemical Composition—The dried rhizome yielded us 1·3 per cent. of a yellowish neutral essential oil of agreeable odour, which in a column of 50 mm. long, deviates 13·8° to the right. By working on a large scale, Messrs. Schimmel & Co., Leipzig, obtain 2·4 to 2·6 per cent.

According to Kurbatow (1873), this oil contains a hydrocarbon, C₁₀H₁₆, boiling at 159° C., and forming a crystalline compound with HCl, and another hydrocarbon boiling at 255-258° C., affording no crystallizable hydrochloric compound. By submitting the oil to fractional distillation, we noticed, above 250°, a blue portion, which may be decolorized by sodium. The crude oil acquires a dark brownish colour on addition of perchloride of iron, but is not at all soluble in concentrated potash solution.

The bitter principle Acorin was extracted by Faust in 1867, as a semi-fluid, brownish glucoside, containing nitrogen, soluble both in ether and in alcohol, but neither in benzol nor in water. In order to obtain this substance, we precipitated the decoction of 10 lb. of the drug by means of tannic acid, and followed the method commonly practised in the preparation of bitter principles. By finally exhausting the residue with chloroform, we succeeded in obtaining a very bitter, perfectly crystalline body, but in so minute a quantity, that we were unable to investigate its nature.

Uses—Sweet Flag is an aromatic stimulant and tonic, now rarely used in regular medicine. It is sold by the herbalist for flavouring beer, and for masticating to clear the voice. It is said to be also used by snuff manufacturers.

Adulteration—The rhizome of the Yellow Flag, Iris Pseudacorus L., is occasionally mixed with that of the Sweet Flag, from which it may be distinguished by its want of aroma, astringent taste, dark colour, and dissimilar structure.

LILIACEÆ.

ALOË.

Aloes; F. Aloès ou Suc d’Aloès; G. Aloë.

Botanical Origin—Several species of Aloë[2539] furnish a bitter juice which when inspissated forms this drug. These plants are natives of arid, sunny places in Southern and Eastern Africa, whence a few species have been introduced into Northern Africa, Spain,[2540] and the East and West Indies.

The aloes are succulent plants of liliaceous habit with persistent fleshy leaves, usually prickly at the margin, and erect spikes of yellow or red flowers. Many are stemless; others produce stems some feet in height, which are woody and branching. In the remote districts of Namaqua Land and Damara Land in Western South Africa, and in the Transkei Territory and Northern Natal to the eastern, aloes have been discovered which attain 30 to 60 feet in height, with stems as much as 12 feet in circumference.[2541] The following species may be named with more or less of certainty as yielding the drug.[2542]

Aloë socotrina Lam. (A. vera Miller), native of the southern shores of the Red Sea and Indian Ocean, Socotra, and Zanzibar (?). It is the source of the Socotrine and Moka Aloes. A. officinalis Forsk. and A. rubescens DC. are considered to be varieties of this plant. A. abyssinica Lam. may probably contribute to the aloes shipped from the Red Sea.

A. vulgaris Lam. A. perfoliata, var. π. vera Linn., A. barbadensis Mill., a plant of India and of Eastern and Northern Africa, now found also on the shores of Southern Spain, Sicily, Greece, and the Canaries; introduced in the beginning of the 16th century (or earlier) into the West Indies. It affords Barbados and Curaçao Aloes. A. indica Royle, a plant of the North-west Provinces of India, common in Indian gardens, appears to be a slight variety of A. vulgaris Lam. A. litoralis König, said to grow in abundance at Cape Comorin, is unknown to us. Dr. Bidie suggests that it is a form of the preceding, stunted by a poor saline soil and exposure to the sea breeze. Both A. indica and A. litoralis are named in the Pharmacopœia of India.

Aloë ferox L., and hybrids obtained by crossing it with A. africana Mill. and A. spicata Thunberg, A. perfoliata Linn. (quoad Roxb.) and A. linguæformis are reputed to yield the best Cape Aloes.

A. africana Mill. and its varieties, and A. plicatilis Mill. afford an extract which Pappe[2543] says is thought to be less powerful.

A. arborescens Mill., A. Commelini Willd. and A. purpurascens Haworth are stated to produce a portion of the Cape Aloes of commerce.[2544]

Various species of Agave, especially A. americana L., are largely grown, since the first half of the 16th century, in the south of Europe, and popularly called Aloë. All of them are plants of Mexico, while the true aloes are natives of the old world. Botanically the genus Agave differs from Aloë, in that the former has the ovary inferior, while in the latter it is superior. From a chemical point of view there is also no analogy at all between Aloë and Agave.

History—Aloes was known to the Greeks as a production of the island of Socotra as early as the 4th century b.c., if we might credit a remarkable legend thus given in the writings of the Arabian geographer Edrisi.[2545] When Alexander had conquered the king of the Persians and his fleets had vanquished the islands of India, and he had killed Pour, king of the Indies, his master Aristotle recommended him to seek the island that produces Aloes. So when he had finished his conquests in India, he returned by way of the Indian Sea into that of Oman, conquered the isles therein, and arrived at last at Socotra, of which he admired the fertility and the climate. And from the advice which Aristotle gave him he determined to remove the original inhabitants and to put Greeks in their place, enjoining the latter to preserve carefully the plant yielding aloes, on account of its utility, and because that without it certain sovereign remedies could not be compounded. He thought also that the trade in and use of this noble drug would be a great advantage for all people. So he took away the original people of the island of Socotra, and established in their stead a colony of Ionians, who remained under his protection and that of his successors, and acquired great riches, until the period when the religion of the Messiah appeared, which religion they embraced. They then became Christians, and so their descendants have remained up to the present time (circa a.d. 1154).

This curious account, which Yule[2546] says is doubtless a fable, but invented to account for facts, is alluded to by the Mahomedan travellers of the 9th century[2547] and in the 10th by Masudi,[2548] who says that in his time aloes was produced only in the island of Socotra, where its manufacture had been improved by Greeks sent thither by Alexander the Great.

Aloes is not mentioned by Theophrastus, but appears to have been well known to Celsus, Dioscorides, Pliny and the author of the Periplus of the Erythrean Sea, as well as to the later Greek[2549] and the Arabian physicians. From the notices of it in the Anglo-Saxon leech-books and a reference to it as one of the drugs recommended to Alfred the Great by the Patriarch of Jerusalem, we may infer that its use was not unknown in Britain as early as the 10th century.[2550]

At this period and for long afterwards the drug was imported into Europe by way of the Red Sea and Alexandria. After the discovery of a route to India by the Cape of Good Hope the old line of commerce probably began to change.

Pires, an apothecary at Cochin, in a letter on Eastern drugs[2551] addressed to Manuel, king of Portugal, in 1516, reports that aloes grows in the island of Çacotora, Aden, Cambaya, Valencia of Arragon, and in other parts,—the most esteemed being that of Çacotora, and next is that of Spain; while the drug of Aden and Cambaya is so bad as to be worthless.

In the early part of the 17th century there was a direct trade in aloes between England and Socotra; and in the records of the East India Company there are many notices of the drug being bought of the “King of Socotra.” Frequently the king’s whole stock of aloes is mentioned as having been purchased.[2552]

Wellstead, who travelled in Socotra in 1833,[2553] says that in old times the aloë was far more largely grown there than at present, and that the walls which enclosed the plantations may still be seen. He adds that the produce was a monopoly of the Sultan of the island. At the present day the few productions of Socotra that are exported are carried by the Arab coasting vessels, coming annually from the Persian Gulf to Zanzibar, at which place they are transshipped for Indian and other ports. Dr. Kirk, who has resided at Zanzibar from 1866 to 1873, informs us that aloes from Socotra arrives in a very soft state packed in goatskins. From these it is transferred to wooden boxes, in which it concretes, and is shipped to Europe and America. To avoid loss the skins have to be washed; and the aloetic liquor evaporated.

Ligon,[2554] who visited the island of Barbados in 1647-50, that is about twenty years after the arrival of the first settlers, speaks of the aloë as if it were indigenous, mentioning also the useful plants which had been introduced. At that period the settlers knew how to prepare the juice for medicinal use, but had not begun to export it. Barbados aloes was in the drug warehouses of London in 1693.[2555]

The manufacture of aloes in the Cape Colony of South Africa was observed by Thunberg in 1773 on the farm of a boer named Peter de Wett, who was the first to prepare the drug in that country.[2556] Cape Aloes is enumerated in the stock of a London druggist in 1780, its cost being set down as £10 per cwt. (1s. 9½d. per lb.).

A new and distinct sort of aloes, manufactured in the colony of Natal, appeared in English commerce in 1870. It will be described further on.

Lignum Aloes—It is important to bear in mind that the word Aloes or Lign Aloës, in Latin Lignum Aloës, is used in the Bible and in many ancient writings to designate a substance totally distinct from the modern Aloes, namely the resinous wood of Aquilaria Agallocha Roxburgh, a large tree[2557] of the order Thymeleaceæ, growing in the Malayan Peninsula. Its wood constituted a drug[2558] which was, down to the beginning of the present century, generally valued for use as incense, but now esteemed only in the East.

Structure of the Leaf—The stout fleshy leaves of an aloë have a strong cuticle and thick-walled epidermis. Their interior substance is formed of very loose, large-celled, colourless pulp, traversed by vascular bundles, which, on transverse section, are seen to be accompanied by a group of large thin-walled cells[2559] containing the bitter juice which constitutes the drug under notice. These cells, on a longitudinal section, are seen to be considerably elongated, adjoining a single row of smaller, prismatic, truncated cells,[2560] by which the former are separated from the cortical layer. The prismatic cells contain a yellow juice, apparently different from that which yields aloes. The cortical tissue is filled with granules of chlorophyll, and exhibits between the cells groups of needles of calcium oxalate. Similar crystals are also found sparingly in the pulp.

The transparent pulp-tissue[2561] is rich in mucilage, which after dilution with water is precipitated by neutral acetate of lead, but is not coagulated by boiling.

The amount of bitter principles in the leaf probably varies with the age of the latter and with the season of the year. Haaxman mentions that, in Curaçao, the maximum is found when the leaves are changing from green to brown.

Cultivation and Manufacture—In Barbados,[2562] where Aloë vulgaris is systematically cultivated for the production of the drug, the plants are set 6 inches apart, in rows which are 1 to 1½ foot asunder, the ground having been carefully prepared and manured. They are kept free from grass and weeds, but yams or pulse are frequently grown between them. The plants are always dwarf, never in the least degree arborescent; almost all of those above a year old bear flowers, which being bright yellow, have a beautiful effect. The leaves are 1-2 feet long; they are cut annually, but this does not destroy the plant, which, under good cultivation, lasts for several years.

The cutting takes place in March and April, and is performed in the heat of the day. The leaves are cut off close to the plant, and placed very quickly, the cut end downwards, in a V-shaped wooden trough, about 4 feet long and 12 to 18 inches deep. This is set on a sharp incline, so that the juice which trickles from the leaves very rapidly flows down its sides, and finally escapes by a hole at its lower end into a vessel placed beneath. No pressure of any sort is applied to the leaves. It takes about a quarter of an hour to cut leaves enough to fill a trough. The troughs are so distributed as to be easily accessible to the cutters. Their number is generally five; and by the time the fifth is filled, the cutters return to the first and throw out the leaves, which they regard as exhausted. The leaves are neither infused nor boiled, nor is any use afterwards made of them except for manure.

When the vessels receiving the juice become filled, the latter is removed to a cask and reserved for evaporation. This may be done at once, or it may be delayed for weeks or even months, the juice, it is said, not fermenting or spoiling. The evaporation is generally conducted in a copper vessel; at the bottom of this is a large ladle, into which the impurities sink, and are from time to time removed as the boiling goes on. As soon as the inspissation has reached the proper point, which is determined solely by the experienced eye of the workman, the thickened juice is poured into large gourds or into boxes, and allowed to harden.

The drug is not always readily saleable in the island, but is usually bought up by speculators who keep it till there is a demand for it in England. The cultivators are small proprietors, but little capable as to mind or means of making experiments to improve the manufacture of the drug. It is said, however, that occasionally a little aloes of very superior kind is made for some special purpose by exposing the juice in a shallow vessel to solar heat till completely dry. But such a drug is stated to cost too much time and trouble to be profitable.[2563] The manufacture of aloes in the Dutch West Indian island of Curaçao is conducted in the same manner.[2564]

The manufacture of aloes in the Cape Colony has been thus described to us in a letter[2565] from Mr. Peter MacOwan of Gill College, Somerset East:—The operator scratches a shallow dish-shaped hollow in the dry ground, spreads therein a goatskin, and then proceeds to arrange around the margin a radial series of aloë leaves, the cut ends projecting inwards. Upon this, a second series is piled, and then a third—care being taken that the ends of each series overhang sufficiently, to drop clear into the central hollow. When these preparations have been made, the operator either “loafs about” after wild honey, or, more likely, lies down to sleep. The skin being nearly filled, four skewers run in and out at the edge square-fashion, give the means of lifting this primitive saucer from the ground, and emptying its contents into a cast-iron pot. The liquid is then boiled, an operation conducted with the utmost carelessness. Fresh juice is added to that which has nearly acquired the finished consistence; the fire is slackened or urged just as it happens, and the boiling is often interrupted for many hours, if neglect be more convenient than attention. In fact, the process is thoroughly barbarous, conducted without industry or reflection; it is mostly carried on by Bastaards and Hottentots, but not by Kaffirs. “The only aloë I have seen used,” says Mr. MacOwan, “is the very large one with di-or tri-chotomous inflorescence,—A. ferox, I believe.” Backhouse[2566] also names “Aloë ferox?” as the species he saw used near Port Elizabeth in 1838.

From another correspondent, we learn that the making of aloes in the Cape Colony is not carried on by preference, but is resorted to when more profitable work is scarce. The drug is sold by the farmers to the merchants of the towns on the coast, some of whom have exerted themselves to obtain a better commodity, and have even imported living aloe-plants from Barbados.

Nothing is known of the manufacture of the so-called Socotrine or Zanzibar Aloes, or even with certainty in what precise localities it is carried on.

General Description—The differences in the several kinds of commercial aloes are due to various causes, such as the species of Aloë employed and the method of extracting the juice. The drug varies exceedingly: some is perfectly transparent and amorphous, with a glassy conchoidal fracture; some is opaque and dark with a dull waxy fracture, or opaque and pallid; or it may be of a light orange-brown and highly crystalline. It varies in consistence in every degree, from dry and brittle to pasty, and even entirely fluid and syrup-like.

These diverse conditions are partially explained by an examination of the very fluid aloes that has been imported of recent years from Bombay. If some of this aloes is allowed to repose, it gradually separates into two portions,—the upper a transparent, black liquid,—the lower, an orange-brown crystalline sediment. If the whole be allowed to evaporate spontaneously, we get aloes of two sorts in the same mass; the one from the upper portion being dark, transparent and amorphous, the other rather opaque and highly crystalline. Should the two layers become mixed, an intermediate form of the drug results.

The Hepatic Aloes of the old writers[2567] was doubtless this rather opaque form of Socotrine Aloes; but the term has come to be used somewhat vaguely for any sort of liver-coloured aloes, and appears to us unworthy to be retained. Much of the opaque, so-called Hepatic Aloes does not however owe its opacity to crystals, but to a feculent matter the nature of which is doubtful.

The odour of aloes is a character which is much depended on by dealers for distinguishing the different varieties, but it can only be appreciated by experience, and certainly cannot be described.[2568]

Varieties—The principal varieties of aloes found in English commerce are the following:—

1. Socotrine Aloes—also called Bombay, East Indian, or Zanzibar Aloes, and when opaque and liver-coloured, Hepatic Aloes. It is imported in kegs and tin-lined boxes from Bombay, whither it has been carried by the Arab traders from the African coast, the Red Sea ports, or by way of Zanzibar, from Socotra. When of fine quality, it is of a dark reddish-brown, of a peculiar, rather agreeable odour, comparable to myrrh or saffron. In thin fragments, it is seen to be of an orange-brown; its powder is of a tawny reddish-brown. When moistened with spirit of wine, and examined in a thin stratum under the microscope, good Socotrine Aloes is seen to contain an abundance of crystals. As imported, it is usually soft, at least in the interior of the mass, but it speedily dries and hardens by keeping.[2569] It is occasionally imported in a completely fluid state (Liquid Socotrine Aloes, Aloë Juice), and is not unfrequently somewhat sour and deteriorated.

Some fine aloes from Zanzibar, of which a very small quantity was offered for sale in 1867, was contained in a skin, and composed of two layers, the one amorphous, the other a granular translucent substance of light colour, which when softened and examined with a lens, was seen to be a mass of crystals. A very bad, dark, fœtid sort of aloes is brought to Aden from the interior. It seems to be the Moka Aloes of some writers.

The quantity of aloes imported into Bombay in the year 1871-72 was 892 cwt., of which 736 cwt. are reported as shipped from the Red Sea ports and Aden.[2570]

2. Barbados Aloes—Characteristic samples show it as a hard dry substance of a deep chocolate-brown, with a clean, dull, waxy fracture. In small fragments it is seen to be translucent and of an orange-brown hue. When breathed upon, it exhales an odour analogous to, but easily distinguishable from, that of Socotrine aloes. It is imported in boxes and gourds. The gourds, into which the aloes has been poured in a melted state through a square hole, over which a bit of calico is afterwards nailed, contain from 10 to 40 lb. or more. Of late years, Barbados aloes having a smooth and glassy fracture has been imported; it is known to the London drug-brokers as “Capey Barbados.” By keeping, it passes into the usual variety having a dull fracture.

The export of aloes from Barbados in 1871, as shown by the Blue Book for that colony, was 1046 cwt., of which 954 cwt. were shipped to the United Kingdom.

3. Curaçao Aloes—manufactured in the Dutch West Indian islands of Curaçao, Bonaire, and Aruba, is imported into this country by way of Holland, packed in boxes of 15 to 28 lb. each. In appearance it resembles Barbados aloes, but has a distinctive odour.

4. Cape Aloes—The special features of this sort of aloes are its brilliant conchoidal fracture and peculiar odour. Small splinters seen by transmitted light are highly transparent and of an amber colour; the powder is of a pale tawny yellow. When the drug is moistened and examined under the microscope, no crystals can be detected, even after the lapse of some days. Cape aloes has the odour of other kinds of aloes, with a certain sourish smell which easily distinguishes it. Several qualities are recognized, chiefly by the greater or lesser brilliancy of fracture, and by the tint of the powder.

From the Blue Book for the Colony of the Cape of Good Hope, published at Cape Town in 1873, it appears that the export of aloes in 1872 was 484,532 lb. (4326 cwt.); and that the average market value during the year was 3¾d., the lowest price, 1½d., being at Riversdale and Mossel Bay, and the highest, 11d., at Swellendam. The drug is shipped from Cape Town, Mossel Bay and Algoa Bay.

5. Natal Aloes—Aloes is also imported from Natal, and since 1870 in considerable quantity. Most of it is of an hepatic kind and completely unlike the ordinary Cape aloes, inasmuch as it is of a greyish-brown and very opaque. Moreover it contains a crystalline principle which has been found in no other sort of aloes.

The drug is manufactured in the upper districts of Natal, between Pietermaritzburg and the Quathlamba mountains, especially in the Umvoti and Mooi River Counties, at an elevation of 2000 to 4000 feet above the sea. The plant used is a large aloë which has not yet been botanically identified. The people who make the drug are British and Dutch settlers, employing Kaffir labourers. The process is not very different from that followed in making Cape aloes, but is conducted with more intelligence. The leaves are cut obliquely into slices, and allowed to exude their juice in the hot sunshine. The juice is then boiled down in iron pots, some care being taken to prevent burning, by stirring the liquid as it becomes thick. The drug while still hot, is poured into wooden cases, in which it is shipped to Europe.[2571] The exports from the colony have been as follows:—[2572]

1868 1869 1870 1871 1872

none 38 cwt. 646 cwt. 372 cwt. 501 cwt.

Chemical Composition—All kinds of aloes have an odour of the same character and a bitter disagreeable taste. The odour which is often not unpleasant, especially in Socotrine aloes, is due to a volatile oil, which the drug contains only in minute proportion. T. and H. Smith of Edinburgh, who contributed a specimen of it to the Vienna Exhibition of 1873, inform us that they obtained it by subjecting to distillation with water 400 lb. of aloes, which quantity they estimate to have yielded about an ounce. The oil is stated in a letter we have received from them, to be a mobile pale yellow liquid, of sp. gr. 0·863, with a boiling point of 266-271° C.

Pure aloes dissolves easily in spirit of wine with the exception of a few flocculi; it is insoluble in chloroform and bisulphide of carbon, as well as in the so-called petroleum ether, the most volatile portion of American petroleum. The sp. gr. of fine transparent fragments of aloes, dried at 100° C., and weighed in the last named fluid at 16° C., was found by one of us (F.) to be 1·364; showing that aloes is much more ponderous than most of the resins, which seldom have a higher sp. gr. than 1·00 to 1·10. In water aloes dissolves completely only when heated. On cooling, the aqueous solution, whether concentrated or dilute, becomes turbid by the separation of resinous drops, which unite into a brown mass,—the so-called Resin of Aloes.[2573] The clear solution, after separation of this substance, has a slightly acid reaction; it is coloured dark brown by alkalis, black by ferric chloride, and is precipitated yellowish-grey by neutral lead acetate. Cold water dissolves about half its weight of aloes, forming an acid liquid which exhibits similar reactions. The solution of aloes in potash or ammonia is precipitated by acids, but not by water.

The most interesting constituents of aloes are the substances known as Aloïn. This name was originally applied to an aloïn which, as it appears to be found exclusively in Barbados aloes, is now termed Barbaloïn, in order to distinguish it from allied substances occurring in Natal and Socotrine aloes.

Barbaloïn was discovered by T. and H. Smith of Edinburgh in 1851,[2574] and was described (1851) by Stenhouse. From good qualities of the drug it can be obtained, according to Tilden,[2575] as a crystalline mass, to the extent of 20 to 25 per cent., but in others it appears to occur partly amorphous or in a chemically altered state. Barbaloïn is a neutral substance, crystallizing in tufts of small yellow prisms. These crystals represent hydrated aloïn, and part with one molecule of water (=2·69 per cent.) by desiccation in vacuo, or by the prolonged heat of a water-bath. Barbaloïn, C₃₄H₃₆O₁₄ + H₂O, dissolves sparingly in water or alcohol but very freely if either liquid be even slightly warmed; it is insoluble in ether.

The solutions alter quickly if made a little alkaline, but if neutral or slightly acid, are by no means very prone to decomposition. By oxidation with nitric acid, barbaloïn yields, as Tilden (1872) has shown, about a third of its weight of chrysammic acid, besides aloëtic, oxalic, and picric acids. It easily combines with bromine to form yellow needles of Bromaloïn, C₃₄H₃₀Br₆O₁₄; Chloraloïn, C₃₄H₃₀Cl₆O₁₄ + 6H₂O, crystallizing in prisms, has likewise been obtained.

In examining Natal aloes in 1871, we observed it to contain a distinct crystalline body, much less soluble than the ordinary aloïn of Barbados aloes. We have accordingly named it Nataloïn.

Nataloïn exists naturally in Natal aloes, from which it can be easily prepared in the crude state, if the drug is triturated with an equal weight of alcohol at a temperature not exceeding 48° C. This will dissolve the amorphous portion, from which the crystals should be separated by a filter, and washed with a small quantity of cold spirit. From 16 to 25 per cent. of crude nataloïn in pale yellow crystals may be thus extracted. When purified by crystallization from methylic alcohol or spirit of wine, it forms thin, brittle, rectangular scales, often with one or more of their angles truncated. The formula assigned to nataloïn by Tilden, which is supported by the composition of the acetyl derivative he has succeeded in obtaining, is C₂₅H₂₈O₁₁.

At 15·5° C., 60 parts of alcohol, 35 of methylic alcohol,[2576] 50 of acetic ether, 1236 of ether, and 230 of absolute alcohol, dissolve respectively one part of nataloïn. It is scarcely more soluble in warm than in cold spirit of wine, so that to obtain crystals it is best to allow the solution to evaporate spontaneously. Water hot or cold dissolves it very sparingly. Nataloïn gives off no water when exposed over oil of vitriol, or to a temperature of 100° C. By the action of nitric acid, it affords both oxalic and picric acids, but no chrysammic acid. It appears not to combine with chlorine or bromine, and we have failed in obtaining from it any such body as bromaloïn.