Chapter VII: Part 7

=Description=—The plant has a perennial root attaining about a foot in length and an inch in diameter. For medicinal use the biennial roots of the cultivated plant are chiefly employed. When fresh they are externally yellowish and wrinkled, white within and of tender fleshy texture. Previous to drying, the thin outer and a portion of the middle bark are scraped off, and the small root filaments are removed. The drug thus prepared and dried consists of simple whitish sticks 6 to 8 inches long, of the thickness of the little finger to that of a quill, deeply furrowed longitudinally and marked with brownish scars. Its central portion, which is pure white, breaks with a short fracture, but the bark is tough and fibrous. The dried root is rather flexible and easily cut. Its transverse section shows the central woody column of undulating outline separated from the thick bark by a fine dark outline shaded off outwards.

The root has a peculiar though very faint odour, and is of rather mawkish and insipid taste, and very slimy when chewed.

[373] Pertz, _Monumenta Germaniæ historica_, Legum tom. i. (1835) 181.—_Ibischa_ from the Greek ὶβίσκος.

=Microscopic Structure=—The greater part of the bark consists of liber, abounding in long soft fibres, to which the toughness of the cortical tissue is due. They are branched and form bundles, each containing from 3 to 30 fibres separated by parenchymatous tissue. Of the cortical parenchyme many cells are loaded with starch granules, others contain stellate groups of oxalate of calcium, and a considerable number of somewhat larger cells are filled with mucilage. The last named on addition of alcohol is seen to consist of different layers.

The woody part is made up of pitted or scalariform vessels, accompanied by a few ligneous cells and separated by a parenchymatous tissue, agreeing with that of the bark. On addition of an alkali, sections of the root assume a bright yellow hue.

=Chemical Composition=—The mucilage in the dry root amounts to about 25 per cent. and the starch to as much more. The former appears from the not very accordant analysis of Schmidt and of Mulder to agree with the formula C₁₂H₂₀O₁₀, thus differing from the mucilage of gum arabic by one molecule less of water. It likewise differs in being precipitable by neutral acetate of lead. At the same time it does not show the behaviour of cellulose, as it does not turn blue by iodine when moistened with sulphuric acid, and it is not soluble in ammoniacal solution of oxide of copper.

The root also contains pectin and sugar (cane-sugar according to Wittstock), and a trace of fatty oil. Tannin is found in very small quantity in the outer bark alone.

In 1826 Bacon, a pharmacien of Caen, obtained from althæa root crystals of a substance at first regarded as peculiar, but subsequently identified with _Asparagin_, C₄H₈N₂O₃, H₂O. It had been previously prepared (1805) by Vauquelin and Robiquet from Asparagus, and is now known to be a widely diffused constituent of plants.[374] Marshmallow root does not yield more than 0·8 to 2·0 per cent. Asparagin crystallizes in large prisms or octohedra of the rhombic system; it is nearly tasteless, and appears destitute of physiological action. Its relation to succinic acid may be thus represented:—

Succinic acid: C₂H₄ {COOH; Asparagin: C₂H₃(NH₂) {CONH₂
{COOH {COOH.

Asparagin is quite permanent whether in the solid state or dissolved, but it is easily decomposed if the solution contains the albuminoid constituents of the root, which act as a ferment. Leguminous seeds, yeast or decayed cheese induce the same change, the final product of which is succinate of ammonium, the asparagin taking the elements of water and hydrogen set free by the fermentation, thus—

C₄H₈N₂O₃ + H₂O + 2H = 2NH₄, C₄H₄O₄
Asparagin. Succinate of Ammonium.

Under the influence of acids or bases, or even by the prolonged boiling of its aqueous solution, asparagin is converted into _Aspartate of Ammonium_, C₄H₆(NH₄)NO₄, of which the hydrated asparagin contains the elements.

[374] It plays an interesting part in the germination of the seeds of papilionaceous and other plants. It is abundant in the young plants, but in most it speedily disappears. Its presence can be proved in the juice by means of the microscope and absolute alcohol, in which latter asparagin is insoluble. See Pfeffer in Pringsheim’s _Jahrb. f. wiss. Bot._ 1872. 533-564.—Borodin in _Bot. Zeitung_, 1878. 801 and seq.

These transformations, especially the former, are undergone by the asparagin in the root, if the latter has been imperfectly dried, or has been kept long, or not very dry. Under such conditions, the asparagin gradually disappears, and the root then yields a brownish decoction, sometimes having a disagreeable odour of butyric acid. There is no doubt that a protein-substance here acts as a ferment. The sections of the root when touched with ammonia or caustic lye should display a bright yellow, not a dingy brown, colour.

The peeled root dried at 100° C. and incinerated afforded us 4·88 of ash, rich in phosphates.

=Uses=—Althæa is taken as a demulcent; it is sometimes also applied as an emollient poultice. It is far more largely used on the continent than in England.

FRUCTUS HIBISCI ESCULENTI.

_Capsulæ Hibisci esculenti_; _Uëhka_, _Okro_, _Okra_, _Bendi-kai_[375]; F. _Gombo_ (in the French Colonies).

=Botanical Origin=—_Hibiscus esculentus_ L. (_Abelmoschus esculentus Guill. et Perr._) an herbaceous annual plant 2 to 3 or even 10 feet high, indigenous to the Old World.[376] It has been found growing abundantly wild on the White Nile by Schweinfurth, and also in 1861 by Col. Grant in Unyoro, 2° N. lat., near the lake Victoria Nyanza, where it is known to the natives as Bameea.

The plant is now largely cultivated in several varieties in all tropical countries.

=History=—The Spanish Moors appear to have been well acquainted with _Hibiscus esculentus_, which was known to them by the same name that it has in Persian at the present day—_Bámiyah_. Abul Abbas el-Nebáti, a native of Seville learned in plants, who visited Egypt in A.D. 1216, describes[377] in unmistakeable terms the form of the plant, its seeds and fruit, which last he remarks is eaten when young and tender with meat by the Egyptians. The plant was figured among Egyptian plants in 1592 by Prosper Alpinus,[378] who mentions its uses as an external emollient.

The powdered fruits as imported from Arabia Felix were known for some time (about the year 1848) in Europe as _Nafé of the Arabs_. They are noticed in the present work from the circumstance that they have a place in the _Pharmacopœia of India_.

=Description=—The fruit is a thin capsule, 4 to 6 or more inches long and about an inch in diameter, oblong, pointed, with 5 to 7 ridges corresponding to the valves and cells, each of which latter contains a single row of round seeds. It is covered with rough hairs and is green or purplish when fresh; it has a slightly sweet mucilaginous taste and a weak herbaceous odour. Like many other plants of the order, _Hibiscus esculentus_ abounds in all its parts with insipid mucilage.

[375] Uëhka in Arabic, according to Schweinfurth. _Okro_ or _Okra_ are common names for the plant in the East and West Indies. _Bendi-kai_, a Canarese and Tamil word, is used by Europeans in the South of India. _Gigambo_ in Curaçao.

[376] Fig. Bentley and Trimen, _Med. Plants_, part 35 (1878).

[377] Ibn Baytar, Sontheimer’s translation, i. 118; Wüstenfeld, _Geschichte der Arab. Aerzte_ etc. 1840. 118.

[378] _De plant. Ægypt._, Venet. 1592. cap. 27.

=Microscopic Structure=—A characteristic part for microscopic examination are the hairs of the fruit. They exhibit at the base one large cell, but their elongated and often slightly curved end is built up at a considerable number of small cells, without any solid contents. The middle and outer zone of the pericarp shows enormous holes filled up with colourless mucilage. In polarized light it is easily seen to be composed of successive layers.

=Chemical Composition=—It is probable that the fruits contain the same mucilage as _Althæa_, but we have had no opportunity of investigating the fact. Landrin[379] says it turns violet with iodine and yields no mucic acid when treated with nitric acid. Popp, who examined the green fruits in Egypt, states[380] that they abound in pectin, starch and mucilage. He found that when dried they afforded 2 to 2·4 per cent. of nitrogen, and an ash rich in salts of lime, potash and magnesia. The ripe seeds gave 2·4-2·5 per cent. of nitrogen; their ash 24 per cent. of phosphoric acid.

=Uses=—The fresh or dried, unripe fruits are used in tropical countries as a demulcent like marshmallow, or as an emollient poultice, for which latter purpose the leaves may also be employed. They are more important from an economic point of view, being much employed for thickening soups or eaten boiled as a vegetable. The root has been recommended as a substitute for that of _Althæa_.[381] The stems of the plant yield a good fibre.

STERCULIACEÆ.

=OLEUM CACAO.=

_Butyrum Cacao_, _Oleum Theobromatis_; _Cacao Butter_, _Oil of Theobroma_; F. _Beurre de Cacao_; G. _Cacaobutter_, _Cacaotalg_.

=Botanical Origin=—Cacao seeds (from which Cacao Butter is extracted) are furnished by _Theobroma Cacao_ L., and apparently also by _Th. leiocarpum_ Bernoulli, _Th. pentagonum_ Bern., and _Th. Salzmannianum_ Bern.[382] These trees are found in the northern parts of South America and in Central America as far as Mexico, both in a wild state and in cultivation.

=History=—Cacao seeds were first noticed by Capitan Gonzalo Fernandez de Oviedo y Valdés (1514-1523), who stated[383] that they had been met with by Columbus, being used among the inhabitants of Yucatan instead of money. They were likewise pointed out to Charles V., by Cortes in one of his letters to the Emperor, dated Temixtitan, Sept. 3rd 1526.[384] The tree as well as the seeds and their uses, were at length described by Benzoni,[385] who lived in the new world from 1541 to 1555. Clusius figured the seeds in his “Notæ in Garciæ Aromatum historiam,” Antwerpiæ, 1582.

[379] _Journ. de Pharm._ 22 (1875) 278.

[380] _Archiv der Pharmacie_, cxcv. (1871) 142.

[381] Della Sudda, _Rép. de Pharm._, Janvier, 1860. 229.

[382] Bernoulli, _Uebersicht der bis jetzt bekannten Arten von Theobroma_.—Reprinted from _Denkschriften der Schweizerischen Gesellschaft für Naturwissenschaften_, xxiv. (Zürich, 1869) 4°. 376.

[383] _Historia general y naturel de las Indias islas y terra firme del mar oceano_, iii. (Madrid, 1853) 253.

[384] Vedia, _Cartas de relacion enviadas al emperador Carlos V. desde Nueva España_. Madrid, 1852. T. 1.

[385] Chavveton (Urbain) _Hist. nouv. du Nouveau Monde ... extraite del’ italien de M. Hierosme Benzoni Milanais_. 1579. p. 504.

Cacao butter was prepared and described by Homberg[386] as early as 1695, at which time it appears to have had no particular application, but in 1719 it was recommended by D. de Quelus[387] both for ointments and as an aliment.

An essay published at Tübingen in 1735[388] called attention to it as “_novum atque commendatissimum medicamentum_.” A little later it is mentioned by Geoffroy[389] who says that it is obtained either by boiling or by expressing the seeds, that it is recommended as the basis of cosmetic pomades and as an application to chapped lips and nipples, and to hæmorrhoids.

=Production=—Cacao butter is procured for use in pharmacy from the manufacturers of chocolate, who obtain it by pressing the warmed seeds. These in the shelled state yield from 45 to 50 per cent. of oil. The natural seeds consist of about 12 per cent. of shell (testa) and 88 of kernels (cotyledons).

=Description=—At ordinary temperatures cacao butter is a light yellowish, opaque, dry substance, usually supplied in the form of oblong tablets having somewhat the aspect of white Windsor soap. Though unctuous to touch, it is brittle enough to break into fragments when struck, exhibiting a dull waxy fracture. It has a pleasant odour of chocolate, and melts in the mouth with a bland agreeable taste. Its sp. gr. is 0·961; its fusing point 20° to 30° C.

Examined under the microscope by polarized light, cacao butter is seen to consist of minute crystals. It is dissolved by 20 parts of boiling absolute alcohol, but on cooling separates to such an extent that the liquid retains not more than 1 per cent. in solution. The fat separated after refrigeration is found to have lost most of its chocolate flavour. Litmus is not altered by the hot alcoholic solution.

Cacao butter in small fragments is slowly dissolved by double its weight of benzol in the cold (10° C.), but by keeping partially separates in crystalline warts.

=Chemical Composition=—The fat under notice is composed, in common with others, of several bodies which by saponification furnish glycerin and fatty acids. Among the latter occurs also oleic acid,[390] contained in that part of the cacao butter which remains dissolved in cold alcohol as above stated. In fact by evaporating that solution a soft fat is obtained. But the chief constituents of cacao butter appear to be stearin, palmitin, and another compound of glycerin containing probably an acid of the same series richer in carbon,—perhaps arachic acid, C₂₀H₄₀O₂, or “_theobromic acid_” C₆₄H₁₂₈O₂, as suggested in 1877 by Kingzett.

[386] _Hist. d. l’Acad. Roy. des Sciences_, tome ii. depuis 1686 jusqu’à 1699, Paris, 1733. p. 248.

[387] _Hist. nat. du Cacao et du Sucre_, Paris, 1719. (According to Haller, _Bibl. Bot._ ii. 158.)

[388] B. D. Mauchart præside—dissertation _Butyrum Cacao_. Resp. Theoph. Hoffmann.

[389] _Tract. de Mat. Med._ ii. (1741) 409.

[390] See article _Amygdalæ dulces_.

=Uses=—Cacao butter, which is remarkable for having but little tendency to rancidity, has long been used in continental pharmacy; it was introduced into England a few years ago as a convenient basis for suppositories and pessaries.

=Adulteration=—The description given of the drug sufficiently indicates the means of ascertaining its purity.

LINEÆ.

SEMEN LINI.

_Linseed_, _Flax Seed_; F. _Semence de Lin_; G. _Leinsamen_, _Flachssamen_.

=Botanical Origin=—_Linum usitatissimum_ L., Common Flax, is an annual plant, native of the Old World, where it has been cultivated from the remotest times. It sows itself as a weed in tilled ground, and is now found in all temperate and tropical regions of the globe. Heer regards it as a variety evolved by cultivation from the perennial _L. angustifolium_ Huds.

=History=—The history of flax, its textile fibre and seed, is intimately connected with that of human civilisation. The whole process of converting the plant into a fibre fit for weaving into cloth is frequently depicted on the wall-paintings of the Egyptian tombs.[391] The grave-clothes of the old Egyptians were made of flax, and the use of the fibre in Egypt may be traced back, according to Unger,[392] as far as the 23rd century B.C. The old literature of the Hebrews[393] and Greeks contains frequent reference to tissues of flax; and fabrics woven of flax have actually been discovered together with fruits and seeds of the plant in the remains of the ancient pile-dwellings bordering the lakes of Switzerland.[394]

The seed in ancient times played an important part in the alimentation of man. Among the Greeks, Alcman in the 7th century B.C., and the historian Thucydides, and among the Romans Pliny, mention linseed as employed for human food. The roasted seed is still eaten by the Abyssinians.[395]

Theophrastus expressly alludes to the mucilaginous and oily properties of the seed. Pliny and Dioscorides were acquainted with its medical application both external and internal. The latter, as well as Columella, exhaustively describes flax under its agricultural aspect. In an edict of the Emperor Diocletian _De pretiis rerum venalium_[396] dating A.D. 301, linseed is quoted 150 _denarii_, sesamé seed 200, hemp seed 80, and poppy seed 150, the _modius castrensis_, equal to about 880 cubic inches.[397] The propagation of flax in Northern Europe as of so many other useful plants was promoted by Charlemagne.[398] It seems to have reached Sweden and Norway before the 12th century.[399]

[391] Wilkinson, _Ancient Egyptians_, iii. (1837) 138, &c.

[392] _Sitzungsberichte der Wiener Akademie_, Juni 1866.

[393] Exod. ix. 31; Lev. xiii. 47, 48; Isaiah xix. 9.

[394] Heer in Trimen’s _Journ. of Bot._ i. (1872) 87.

[395] A. de Candolle, _Géogr. Botanique_, 835.—A. Braun, _Flora_, 1848. 94.

[396] See p. 65, note 1.

[397] The English _imperial gallon_ = 277·27 cubic inches.

[398] For further historical information on flax in ancient times, we may refer to Hehn, _Kulturpflanzen und Hausthiere ..._ Berlin, 1870. 97, 430.

[399] Schübeler, _Die Pflanzenwelt Norwegens_, Christiania, 1873-1875. p. 332.

=Description=—The capsule which is globose splits into 5 carpels, each containing two seeds separated by a partition. The seeds are of flattened, elongated ovoid form with an acute edge, and a slightly oblique point blunt at one end. They have a brown, glossy, polished surface which under a lens is seen to be marked with extremely fine pits. The hilum occupies a slight hollow in the edge just below the apex. The testa which is not very hard encloses a thin layer of albumen surrounding a pair of large cotyledons having at their pointed extremity a straight embryo. The seeds of different countries vary from ¼ to ⅙ of an inch in length, those produced in warm regions being larger than those grown in cold. We find that 6 seeds of Sicilian linseed, 13 of Black Sea and 17 of Archangel linseed weigh respectively _one grain_.

When immersed in water, the seeds become surrounded by a thin, slippery, colourless, mucous envelope, which quickly dissolves as a neutral jelly, while the seed slightly swells and loses its polish. The seed when masticated has a mucilaginous oily taste.

=Microscopic Structure=—On examining the testa under almond oil or oil of turpentine, the outlines of the epidermal cells are not distinctly visible. But under dilute glycerin or in water the epidermis quickly swells up to 3 or 4 times its original thickness; on warming, the entire epidermis is resolved into mucilage, except a thin skeleton of cell-walls, which withstands even the action of caustic lye. The formation of the mucilage may be conveniently studied by the use of a solution of ferrous sulphate, with which thin sections of the testa should be moistened. Other structural peculiarities may be seen if they are imbued with concentrated sulphuric acid, washed and then moistened with a solution of iodine. The application of polarized light is also useful. By the latter means crystalloid granules of albuminoid matter become visible if the sections are examined under oil. The tissue of the albumen and the cotyledons abounds in drops of fatty oil.

=Chemical Composition=—The constituent of chief importance is the fixed oil which the seed contains to about ⅓ of its weight. The proportion obtained by pressure on a large scale is 20 to 30 per cent. varying with the quality of the seed. The oil when pressed without heat and when fresh has but little colour, is without unpleasant taste, and does not solidify till cooled to -20° C. The commercial oil however is dark yellow, and has a sharp repulsive taste and odour. On exposure to the air, especially after having been heated with oxide of lead, it quickly dries up to a transparent varnish consisting chiefly of _Linoxyn_, C₃₂H₅₄O₁₁. The crude oil increases in weight 11 to 12 per cent., although at the same time its glycerin is destroyed by oxidation.

By saponification, linseed oil yields glycerin, and 95 per cent. of fatty acids, consisting chiefly of _Linoleic Acid_, C₁₆H₂₆O₂, accompanied by some oleic, palmitic, and myristic acid. The action of the air transforms linoleic acid into the resinoid _Oxylinoleic Acid_, C₁₆H₂₆O₅. Linoleic acid appears to be contained in all drying oils, notably in that of poppy seed. It is not homologous either with ordinary fatty acids or with the oleic acid of oil of almonds, C₁₈H₃₄O₂. The chemistry of the drying oils, especially those of linseed and poppy, has been particularly investigated by Mulder.[400]

The viscid mucilage of linseed cannot be filtered till it has been boiled. It contains in the dry state more than 10 per cent. of mineral substances, when freed from which and dried at 110° C. it corresponds, like althæa-mucilage, to the formula C₁₂H₂₀O₁₀. The seeds by exhaustion with cold or warm water afford of it about 15 per cent. By boiling nitric acid it yields crystals of mucic acid; by dilute mineral acids it is broken up into dextrogyre gum and sugar and cellulose.[401]

Linseed contains about 4 per cent. of nitrogen corresponding to about 25 per cent. of protein-substances. After expression of the oil these substances remain in the cake so completely that the latter contains 5 per cent. of nitrogen, and constitutes a very important article for feeding cattle.

In the ripe state linseed is altogether destitute of starch, though this substance is found in the immature seed in the very cells which subsequently yield the mucilage. The latter may be regarded as in analogous cases to be a product of the transformation of starch.

The amount of water retained by the air-dry seed is about 9 per cent.

The mineral constituents of linseed, chiefly phosphates of potassium, magnesium, and calcium, amount on an average to 3 per cent., and pass into the mucilage. By treating thin slices of the testa and its adhering inner membrane with ferrous sulphate, it is seen that this integument is the seat of a small amount of tannin.

=Production and Commerce=—Flax is cultivated on the largest scale in Russia, from which country there was imported into the United Kingdom in 1872 linseed to the value of 3 millions sterling. The shipments were made in about equal proportion from the northern and the southern ports of Russia.

The imports from India in the same year amounted in value to £1,144,942, and from Germany and Holland to £144,108. The total import in 1872 was 1,514,947 quarters, value £4,513,842.

The cultivation of flax in Great Britain appears to be declining. The area under this crop in 1870 was 23,957 acres; in 1871, 17,366 acres; in 1872, 15,357 acres; and in 1873, 14,683 acres. The last named area reckoning the yield at 2 to 2½ quarters of seed per acre would represent a production of about 30,000 to 38,000 quarters.

[400] His numerous investigations on this subject have been published in a separate pamphlet, of which we have before us a German translation: G. J. Mulder, _Die Chemie der austrocknenden Oele_ ... Berlin, 1867, pp. 255.

[401] Kirchner and Tollens, _Annalen der Chemie_, 175 (1874) 215.

In English price-currents, eight sorts of linseed are enumerated, namely, English, Calcutta, Bombay, Egyptian, Black Sea and Azof, Petersburg, Riga, Archangel. The first three appear to fetch the highest prices.

=Uses=—In medicine, linseed is chiefly used in the form of poultice which may be made either of the seed simply ground or of the pulverized cake. In either case the powder should not be long stored, as the oil in the comminuted seed is rapidly oxidized and fatty acids produced. An infusion of the seeds called _Linseed Tea_ is a common popular demulcent remedy.

=Adulteration=—Linseed is very liable to adulteration with other seeds, especially when the commodity is scarce. The admixture in question is due in part to careless harvesting and in part to intentional additions. In 1864 the impure condition of the linseed shipped to the English market had become so detrimental to the trade that the importers and crushers founded an association called _The Linseed Association of London_, by which they bound themselves to refuse all linseed containing more than 4 per cent. of foreign seeds, and this step very rapidly improved the quality of the article.[402]

[402] Greenish in _Yearbook of Pharmacy_, 1871. 590; _Pharm. Journ._ Sept. 9, 1871. 211.

As the druggist has to _purchase_ linseed meal, he must of necessity rely to some extent on the character of the oil-presser from whom he derives his supplies. The presence of the seeds of _Cruciferæ_ (as rape and mustard) which is common, may be recognized by the pungent odour of the essential oil which they develope in contact with water. The introduction of cereals would also be easily discovered by iodine, which strikes no blue colour in a decoction of linseed. The microscope will also afford important aid in the examination of linseed cake or meal.

ZYGOPHYLLEÆ.

LIGNUM GUAIACI.

_Lignum sanctum_; _Guaiacum Wood_, _Lignum Vitæ_; F. _Bois de Gaïac_; G. _Guaiakholz_, _Pockholz_.

=Botanical Origin=—This wood is furnished by two West Indian species of _Guaiacum_, namely:—

1. _G. officinale_ L., a middle-sized or low evergreen tree, with light blue flowers, parapinnate leaves having ovate, very obtuse leaflets in 2, less often in 3 pairs, and 2-celled fruits. It grows in Cuba, Jamaica (abundantly on the arid plains of the south side of the island), Les Gonaives in the N.W. of Hayti (plentiful), St. Domingo, Martinique, St. Lucia, St. Vincent, Trinidad, and the northern coast of the South American continent. This tree affords the Lignum Vitæ of Jamaica (of which very little is imported), a portion of that shipped from the ports of Hayti, and probably the small quantity exported by the United States of Colombia.

2. _G. sanctum_ L., a tree much resembling the preceding, but distinguishable by its leaves having 3 to 4 pairs of leaflets which are very obliquely obovate or oblong, passing into rhomboid-ovate, and mucronulate; and a 5-celled fruit. It is found in Southern Florida, the Bahama Islands, Key West, Cuba, St. Domingo (including the part called Hayti) and Puerto Rico, and is certainly the source of the small but excellent Lignum Vitæ exported from the Bahamas as well as of some of that shipped from Hayti.

=History=—There can be no doubt but that the earliest importations of Lignum Vitæ were obtained from St. Domingo, of which island, Oviedo[403] who landed in America in 1514 mentions the tree, under the name of _Guayacan_, as a native. He points out its fruits as yellow and resembling two joined lupines, which could only be said with reference to _G. officinale_, and would not apply to the ovoid five-cornered fruits of _G. sanctum_. Oviedo appears however to have been aware of two species, one of which he found in Española (St. Domingo) as well as in Nagrando (Nicaragua) and the other in the island of St. John (Puerto Rico), whence it was called _Lignum sanctum_.

The first edition of Oviedo was printed in 1526; but some years before this the wood must have been known in Germany, as is evident by the treatises written in 1517, 1518, and 1519 by Nicolaus Poll,[404] Leonard Schmaus[405] and Ulrich von Hutten.[406] The last which gives a tolerable description of the tree, its wood, bark, and medicinal properties, was translated into English in 1533 by Thomas Paynel, canon of Merton Abbey, and published in London in 1536 under the title—“_Of the wood called Guaiacum that healeth the Frenche Pockes and also helpeth the gout in the feete, the stoone, the palsey, lepree, dropsy, fallynge euyll, and other dyseases._” It was several times reprinted.

In the old pharmacy the products of destructive distillation of guaiacum wood were known as _Oleum ligni sancti_. It must have consisted of the substances which we mention further on in the following article.

=Description=—The wood (always known in commerce as _Lignum Vitæ_) as imported consists of pieces of the stem and thick branches, usually stripped of bark, and often weighing a hundredweight each. It is remarkably heavy and compact. Its sp. gr. which exceeds that of most woods is about 1·3.

Lignum Vitæ is mostly imported for turnery,[407] and the chips, raspings and shavings are the only form in which it is commonly seen in pharmacy. A stem 7 to 8 inches in diameter cut transversely exhibits a light-yellowish zone of sapwood about an inch wide, enclosing a sharply defined heartwood of a dark greenish brown. Both display alternate lighter and darker layers, which especially in the sapwood are further distinguished by groups of vessels. In this manner are formed a large number of circles resembling annual rings, the general form of which is evident, though the individual rings are by no means well defined. More than 20 such rings may be counted in the sapwood of a log such as we have mentioned, and more than 30 in the heartwood. The pithless centre is usually out of the axis. The medullary rays are not visible to the naked eye, but may be seen by a lens to be very numerous and equidistant. The pores of the heartwood may be distinguished as containing a brownish resin, while those of the outermost layer of sapwood are empty.

[403] _Natural Hystoria de las Indias_, Toledo, 1526. fol. xxxvii.

[404] _Decura Morbi Gallici per Lignum Guayacanum libellus_, printed in 1535 but dated 19 Dec. 1517, 8 pages 8°.

[405] _De Morbo Gallico tractatus_, Salisburgi, November 1518,—reprinted in the _Aphrodisiacus_ of Luisinus, Lugd. Bat. 1728. 383.—We have only seen the latter.

[406] _Ulrichi de Hutten equitis de Guaiaci medicina et morbo gallico liber unus_, 4°. (26 chapters) Moguntiæ, 1519.

[407] It is much used for the wheels (technically “_sheaves_”) of ships’ blocks (pulleys), the circumference of which ought to consist of the white sapwood. It is also required for caulking mallets, skittle balls and for the large balls used in American bowling alleys, for which purposes it should be as sound and homogeneous as possible.

In the thickest pieces sapwood is wanting, and even in stems of about a foot in diameter it is reduced to ⅕ of an inch. It is of looser texture than the heartwood and floats on water, whereas the latter sinks. Both sapwood and heartwood owe their tenacity to an extremely peculiar zigzag arrangement[408] of the woody bundles. The sapwood is tasteless. The heartwood has a faintly aromatic and slightly irritating taste, and when heated or rubbed emits a weak agreeable odour.

The bark which was formerly officinal but is now almost obsolete, is very rich in oxalate of calcium and affords upon incineration not less than 23 per cent. of ash. It contains a resin distinct from that of the wood, and also a bitter acrid principle.[409]

The Lignum Vitæ of Jamaica (_G. officinale_) and that of the Bahamas (_G. sanctum_), of which authentic specimens have been kindly placed at our disposal by Mr. G. Shadbolt, display the same appearance as well as microscopic structure.[410]

=Microscopic Structure=—The wood consists for the most part of pointed, not very long, ligneous cells (libriform), traversed by one-celled rows of medullary rays. There are also thin layers of parenchymatous tissue, to which the zones apparent in a transverse section of the drug are due. The pitted vessels are comparatively large but not very numerous. The structure of the sapwood is the same as that of the heartwood, but in the latter the ligneous cells are filled with resin. The parenchymatous cells contain crystals of oxalate of calcium.

=Chemical Composition=—The only constituent of any interest is the resin which the heartwood contains to the extent of about a fourth of its weight. The sapwood afforded us 0·91 and the heartwood 0·60 per cent. of ash.

=Commerce=—Lignum Vitæ varies much in estimation, according to size, soundness, and the cylindrical form of the logs. The best is exported from the city of Santo Domingo, whither it is brought from the interior of the island. The quantity shipped from this port during 1871 was 1494 tons;[411] 220 tons were exported in 1877 from Puerto Plata on the northern coast of the island. The wood obtained from the Haytian ports (of the western part of the same island) is much less esteemed in the London market.

[408] It has been remarkably well pointed out already by Valerius Cordus (_obiit_ 1544). See Gesner’s edition of his _Hist. Stirpium Argentorat_., 1561. 191.

[409] See also Oberlin et Schlagdenhauffen, _Journ. de Pharm._ 28 (1878) 246 and plate vi.

[410] That of _Guaiacum arboreum_ DC. is apparently very different. This tree, occurring in New Granada, has already been noticed (1571-1577) by Francisco Hernandez (_Nova plantarum, animal, et mineral. mexicanor. hist._, Romæ 1651, fol. 63) under the name of _Guayacan_. He mentions its large umbels with yellow flowers, those of Guaiacum officinale, the “_Hoaxacan_” or Lignum sanctum, being blue. In the _Prodromus Floræ Neo-Granatentis_ (_Ann. Scienc. nat._ xv., 1872. p. 361) J. E. Planchon also describes Guaiacum arboreum, known there as _Guayacan polvillo_; its wood is of an almost pulverulent fracture.

[411] _Consular Reports_ presented to Parliament, Aug. 1872.

Some small wood of good quality comes from the Bahamas, and an ordinary quality, also small, from Jamaica. From the latter island, the quantity exported in 1871 was only 14 tons;[412] from the Bahamas in the same year 199 tons.[413] Lignum Vitæ was shipped from Santa Marta in 1872 to the extent of 115 tons.[414]

Hamburg is also an important place for the wood under notice; in 1877 there were imported 22,404 centners from S. Domingo and 3551 centners from Venezuela.

=Uses=—Guaiacum wood is only retained in the pharmacopœia as an ingredient of the Compound Decoction of Sarsaparilla. It is probably inert, at least in the manner in which it is now administered.[415]

=Adulteration=—In purchasing guaiacum chips it is necessary to observe that the non-resinous sapwood is absent, and still more that there is no admixture of any other wood. A spurious form of the drug seems to be by no means rare in the United States.[416]

RESINA GUAIACI.

_Guaiacum Resin_; F. _Résine de Gaïac_; G. _Guaiakharz_.

=Botanical Origin=—_Guaiacum officinale_ L., see preceding article.

=History=—Hutten[417] in 1510 stated that guaiacum wood when set on fire exudes a blackish resin which quickly hardens, but of which he knew no use. The resin was in fact introduced into medicine much later than the wood. The first edition of the _London Pharmacopœia_ in which we find the former named is that of 1677.

=Production=[418]—In the island of St. Domingo, whence the supplies of guaiacum resin are chiefly derived, the latter is collected from the stems of the trees, in part as a natural exudation, and in part as the result of incisions made in the bark. In some districts as in the island of Gonave near Port-au-Prince, another method of obtaining it is adopted. A log of the wood is supported in a horizontal position above the ground by two upright bars. Each end of the log is then set on fire, and a large incision having been previously made in the middle, the melted resin runs out therefrom in considerable abundance. 36,350 lbs. of it have been exported in 1875 from Port-au-Prince.

The resin is collected chiefly from _G. officinale_, which affords it in greater plenty than _G. sanctum_.

[412] Blue Book—Island of Jamaica for 1871.

[413] Blue Book for Colony of Bahamas for 1871.

[414] _Consular Reports_, Aug. 1873. 746.

[415] The ancient treatment of syphilis by guaiacum which gained for the drug such immense reputation, consisted in the administration of vast quantities of the decoction, the patient being shut up in a warm room and kept in bed.—See Hutten’s pamphlet quoted before, and its numerous reprints and translations.

[416] Schulz, in the (Chicago) _Pharmacist_, Sept. 1873.

[417] _Op. cit._ at p. 101.

[418] We have to thank Mr. Eugène Nau of Port-au-Prince for the information given under this head, as well as for some interesting specimens.

=Description=—The resin occurs in globular tears ½ an inch to 1 inch in diameter, but much more commonly in the form of large compact masses, containing fragments of wood and bark. The resin is brittle, breaking with a clean, glassy fracture; in thin pieces it is transparent and appears of a greenish brown hue. The powder when fresh is grey, but becomes green by exposure to light and air. It has a slight balsamic odour and but little taste, yet leaves an irritating sensation in the throat.

The resin has a sp. gr. of about 1·2. It fuses at 85° C., emitting a peculiar odour somewhat like that of benzoin. It is easily soluble in acetone, ether, alcohol, amylic alcohol, chloroform, creosote, caustic alkaline solutions, and oil of cloves; but is not dissolved or only partially by other volatile oils, benzol or bisulphide of carbon. By oxidizing agents it acquires a fine blue colour, well shown when a fresh alcoholic solution is allowed to dry up in a very thin layer and this is then sprinkled with a dilute alcoholic solution of ferric chloride. Reducing agents of all kinds, and heat produce decoloration. An alcoholic solution may be thus blued and decolorized several times in succession, but it loses at length its susceptibility. This remarkable property of guaiacum was utilized by Schönbein in his well-known researches on ozone.

=Chemical Composition=—The composition of guaiacum resin was ascertained by Hadelich (1862) to be as follows:—

Guaiaconic Acid, 70·3 per cent.
Guaiaretic Acid, 10·5 ”
Guaiac Beta-resin, 9·8 ”
Gum, 3·7 ”
Ash constituents, 0·8 ”
Guaiacic Acid, colouring matter (Guaiac-yellow),
and impurities, 4·9 ”

If the mother-liquor obtained in the preparation of the potassium salt of guaiaretic acid (_vide infra_) is decomposed by hydrochloric acid, and the precipitate washed with water, ether will extract from the mass _Guaiaconic Acid_, a compound discovered by Hadelich, having the formula C₃₈H₄₀O₁₀. It is a light brown, amorphous substance, fusing at 100° C. It is without acid reaction but decomposes alkaline carbonates, forming uncrystallizable salts easily soluble in water or alcohol. It is insoluble in water, benzol, or bisulphide of carbon, but dissolves in ether, chloroform, acetic acid or alcohol. With oxidizing agents it acquires a transient blue tint.

_Guaiaretic Acid_, C₂₀H₂₆O₄, discovered by Hlasiwetz in 1859, may be extracted from the crude resin by alcoholic potash or by quicklime. With the former it produces a crystalline salt; with the latter an amorphous compound: from either the liquid, which contains chiefly a salt of guaiaconic acid, may be easily decanted. Guaiaretic acid is obtained by decomposing one of the salts referred to with hydrochloric acid, and crystallizing from alcohol. The crystals, which are soluble also in ether, benzol, chloroform, carbon bisulphide or acetic acid, but neither in ammonia nor in water, melt below 80° C., and may be volatilized without decomposition. The acid is not coloured blue by oxidizing agents.

By exhausting guaiacum resin with boiling bisulphide of carbon a slightly yellowish solution is obtained (containing chiefly guaiaretic acid?), which, on addition of concentrated sulphuric acid, turns beautifully red.

After the extraction of the guaiaconic acid there remains a substance insoluble in ether to which the name _Guaiac Beta-resin_ has been applied. It dissolves in alcohol, acetic acid or alkalis, and is precipitated by ether, benzol, chloroform or carbon bisulphide in brown flocks, the composition of which appears not greatly to differ from that of guaiaconic acid.

_Guaiacic Acid_, C₁₂H₁₆O₆, obtained in 1841 by Thierry from guaiacum wood or from the resin, crystallizes in colourless needles. Hadelich was not able to obtain more than one part from 20,000 of guaiacum resin.

Hadelich’s _Guaiac-yellow_, the colouring matter of guaiacum resin, first observed by Pelletier, crystallizes in pale yellow quadratic octohedra, having a bitter taste. Like the other constituents of the resin, it is not a glucoside.

The decomposition-products of guaiacum are of peculiar interest. On subjecting the resin to dry distillation in an iron retort and rectifying the distillate, _Guaiacene_ (_Guajol_ of Völckel), C₅H₈O, passes over at 118° C. as a colourless neutral liquid having a burning aromatic taste.

At 205°-210° C., there pass over other products, _Guaiacol_, C₆H₄·OCH₃·OH, (methylic ether of pyrocatechin), and _Kreosol_ C₆H₃·OH(CH₃)₂. Both are thickish, aromatic, colourless liquids, which become green by caustic alkalis, blue by alkaline earths, and are similar in their chemical relations to eugenic acid. Guaiacol has been prepared synthetically by Gorup-Besanez (1868) by combining iodide of methyl, CH₃I, with pyrocatechin, C₆H₄(OH)₂.

After the removal by distillation of the liquids just described, there sublime upon the further application of heat pearly crystals of _Pyroguaiacin_, C₃₈H₄₄O₆, an inodorous substance melting at 180° C. The same compound is obtained together with guaiacol by the dry distillation of guaiaretic acid. Pyroguaiacin is coloured green by ferric chloride, and blue by warm sulphuric acid. The similar reactions of the crude resin are probably due to this substance (Hlasiwetz).

Beautiful coloured reactions are likewise exhibited by two new acids which Hlasiwetz and Barth obtained (1864) in small quantity together with traces of fatty volatile acids, by melting purified resin of guaiacum with potassium hydrate. One of them is isomeric with pyrocatechuic acid.

=Uses=—Guaiacum resin is reputed diaphoretic and alterative. It is frequently prescribed in cases of gout and rheumatism.

=Adulteration=—The drug is sometimes imported in a very foul condition and largely contaminated with impurities arising from a careless method of collection.

RUTACEÆ.

CORTEX ANGOSTURÆ.

_Cortex Cuspariæ_; _Angostura Bark_, _Cusparia Bark_, _Carony Bark_; F. _Ecorce d’Angusture de Colombie_; G. _Angostura-Rinde_.

=Botanical Origin=—_Galipea Cusparia_ St. Hilaire (_G. officinalis_ Hancock, _Bonplandia trifoliata_ Willd., _Cusparia trifoliata_ Engler 1874, _Flora Brasil_. 113), a small tree, 12 to 15 feet high, with a trunk 3 to 5 inches in diameter, growing in abundance on the mountains of San Joaquin de Caroni in Venezuela, between 7° and 8° N. lat., also according to Bonpland[419] near Cumana. According to Hancock,[420] who was well acquainted with the tree, it is also found in the Missions of Tumeremo, Uri, Alta Gracia, and Cupapui, districts lying eastward of the Caroni and near its junction with the Orinoko. The bark is brought into commerce by way of Trinidad.

=History=—Angostura Bark is said to have been used in Madrid by Mutis as early as 1759[421] (the year before he left Spain for South America,) but it was certainly unknown to the rest of Europe until much later. Its real introducer was Brande, apothecary to Queen Charlotte, and father of the distinguished chemist of the same name, who drew attention to some parcels of the bark imported into England in 1788.[422] In the same year a quantity was sent to a London drug firm by Dr. Ewer of Trinidad, who describes it[423] as brought to that island from Angostura by the Spaniards. The drug continued to arrive in Europe either by way of Spain or England, and its use was gradually diffused. In South America it is known as _Quina de Caroni_ and _Cascarilla del Angostura_.

=Description=—The bark occurs in flattish or channelled pieces, or in quills rarely as much as 6 inches in length and mostly shorter. The flatter pieces are an inch or more in width and ⅛ of an inch in thickness. The outer side of the bark is coated with a yellowish-grey corky layer, often soft enough to be removeable with the nail, and then displaying a dark brown, resinous under surface. The inner side is light brown with a rough, slightly exfoliating surface indicating close adhesion to the wood, strips of which are occasionally found attached to it; the obliquely cut edge also shows that it is not very easily detached. The bark has a short, resinous fracture, and displays on its transverse edge sharply defined white points, due to deposite of oxalate of calcium. It has a bitter taste and a nauseous musty odour.

[419] Humboldt, _Reise in die Aequinoctialgegenden des neuen Continents_, iv. (Stuttgart, 1860), 252.—Humboldt and Bonpland in 1804 obtaining, from the Caroni river, flowering branches of the “_Cuspa_” (_l. c._ 1. 300) or “_Cuspare_,” as it is called by the Indians, believed it to constitute a new genus. In 1824 St. Hilaire ascertained it to belong to the genus Galipea.

The tree is figured in Bentley and Trimen, _Med. Plants_, part 26 (1877).

[420] _Observations on the Orayuri or Angustura Bark Tree_,—_Trans. of Medico-Botanical Society_, 1827-29.—Hancock endeavoured to prove his tree distinct from _G. Cusparia_ St. Hil., but Farre and Don who subsequently examined his specimens decided that the two were the same. With the assistance of Prof. Oliver, I also have examined (1871) Hancock’s plant, comparing it with his figure and other specimens, and have arrived at the conclusion that it is untenable as a distinct species.—D. H.

[421] Martiny, _Encyklopädie_, i. (1843) 242.

[422] Brande, _Experiments and Observations on the Angustura Bark_. 1791. 2nd ed. 1793.

[423] _London Med. Journ._ x. (1789) 154.

=Microscopic Structure=—The most striking peculiarity is the great number of oil-cells scattered through the tissue of the bark. They are not much larger than the neighbouring parenchymatous cells, and are loaded with yellowish essential oil or small granules of resin. Numerous other cells contain bundles of needle-shaped crystals of oxalate of calcium or small starch granules. The liber exhibits bundles of yellow fibres, to which the foliaceous fracture of the inner bark is due. The structure of the bark under notice has been very minutely described and figured by Oberlin and Schlagdenhauffen.[424]

=Chemical Composition=—Angostura bark owes its peculiar odour to an essential oil which it was found by Herzog[425] to yield to the extent of ¾ per cent. It is probably a mixture of a hydrocarbon (C₁₀H₁₆) with an oxygenated oil. Its boiling point is 266° C. Oberlin and Schlagdenhauffen obtained 0·19 per cent. of the oil, and found it to be slightly dextrogyre; it assumes a fine red colour when shaken with aqueous ferric chloride, and turns yellow with concentrated sulphuric acid.

[424] _Journ. de Pharm. et de Chimie_, 28 (1877), 226; plates I, II, III. The bark is also figured by Berg, _Anatomischer Atlas_, Tab. 37.

[425] _Archiv d. Pharm._ xcii. (1858) 146.

The bitter taste of the bark is attributed to a substance pointed out in 1833 by Saladin and named _Cusparin_. It is said to be crystalline, neutral, melting at 45° C., soluble in alcohol, sparingly in water, precipitable by tannic acid. The bark is stated to yield it to the extent of 1·3 per cent. Herzog endeavoured to prepare it but without success, nor have Oberlin and Schlagdenhauffen met with it. The latter chemists, on the other hand, isolated an alkaloid _Angosturine_ C₁₀H₄₀NO₁₄. It is in thin prisms, melting at 85° and yielding a crystallized chlorhydrate or sulphate. Angosturine turns red when touched with concentrated sulphuric acid, or green if nitric acid or iodic acid, or other oxydizing substances, have been previously mixed with the sulphuric acid. The alcoholic solution of the alkaloid is of decidedly alkaline reaction. A cold aqueous infusion of angostura bark yields an abundant red-brown precipitate with ferric chloride. Thin slices of the bark are not coloured by solution of ferrous sulphate, so that tannin appears to be absent.

=Uses=—Angostura bark is a valuable tonic in dyspepsia, dysentery and chronic diarrhœa, but is falling into disuse.

=Adulteration=—About the year 1804, a quantity of a bark which proved to be that of _Strychnos Nux Vomica_ reached Europe from India, and was mistaken for Cusparia. The error occasioned great alarm and some accidents, and the use of angostura was in some countries even prohibited. The means of distinguishing the two barks (which are not likely to be again confounded) are amply contained in the above-given descriptions and tests, and at length pointed out by Oberlin and Schlagdenhauffen. They also described the bark of _Esenbeckia febrifuga_ Martius (_Evodia febrifuga_ Saint Hilaire), a Brazilian tree belonging to the same natural order. Maisch[426] was the first to draw attention to this “_new false Angostura bark_.” It is at once distinguished by being devoid of aromatic properties; its taste is purely bitter.

FOLIA BUCHU.

_Folia Buceo_; _Buchu_, _Bucchu_, _Bucha or Buka Leaves_; F. _Feuilles de Bucco_; G. _Bukublätter_.

=Botanical Origin=—The Buchu leaves are afforded by three species of _Barosma_.[427] The latter are erect shrubs some feet in height, with glabrous rod-like branches, opposite leaves furnished with conspicuous oil-cells on the toothed margin as well as generally on the under surface. The younger twigs and several parts of the flower are also provided with oil-cells. The white flowers with 5-partite calyx, and the fruit formed of five erect carpels, are often found, together with small leafy twigs, in the drug of commerce.

The leaves of the three species referred to may be thus distinguished:—

1. _Barosma crenulata_ Hook. (_B. crenata_ Kunze).—Oblong, oval, or obovate, obtuse, narrowed towards the base into a distinct petiole; margin serrulate or crenulate; dimensions, ¾ to 1½ inches long, ³/₁₀ to ⁴/₁₀ of an inch wide.

2. _B. serratifolia_ Willd.—Linear-lanceolate, equally narrowed towards either end, three-nerved, apex truncate always furnished with an oil-cell; margin sharply serrulate; 1-1½ inches long by about ²/₁₀ of an inch wide.

3. _B. betulina_ Bartling.—Cuneate-obovate, apex recurved; margin sharply denticulate, teeth spreading; ½ to ¾ of an inch long by ³/₁₀ to ⁵/₁₀ wide. Substance of the leaf more harsh and rigid than in the preceding.

_B. crenulata_ and _B. betulina_ grow in the Divisions of Clanwilliam and Worcester, north and north-east of Cape Town, and the former even on Table Mountain close to the capital; _B. serratifolia_ is found in the Division of Swellendam farther south.

=History=—The use of Buchu leaves was learnt from the Hottentots by the colonists of the Cape of Good Hope. The first importations of the drug were consigned to the house of Reece & Co., of London, who introduced it to the medical profession in 1821.[428] The species appears to have been _B. crenulata_.

=Description=—In addition to the characters already pointed out, we may observe that buchu leaves of either of the kinds mentioned are smooth and glabrous, of a dull yellowish-green hue, somewhat paler on the under side, on which oil-cells in considerable number are perceptible.

[426] _Am. Journ. of Pharm._ 1874. 50; also _Yearbook of Pharm._ 1874. 91.

[427] From βαρὺς, _heavy_, and ὀσμὴ, _odour_.

[428] R. Reece, _Monthly Gazette of Health_ for Feb. 1821. 799.

The leaves of _B. crenulata_ vary in shape and size in different parcels, in some the leaves being larger and more elongated than in others, probably according to the luxuriance of the bushes in particular localities. Those of _B. serratifolia_ and _B. betulina_ present but little variation. Each kind is always imported by itself. Those of _B. betulina_ are the least esteemed, and fetch a lower price than the others, yet appear to be quite as rich in essential oil.

Buchu leaves have a penetrating peculiar odour and a strongly aromatic taste.

=Microscopic Structure=—The essential oil is contained in large cells close beneath the epidermis of the under side of the leaf. The oil-cells are circular and surrounded by a thin layer of smaller cells; they consequently partake of the character of the oil-ducts in the aromatic roots of _Umbelliferæ_ and _Compositæ_. The latter, however, are elongated.

The upper side of the leaf of _Barosma_ exhibits an extremely interesting peculiarity[429]. There is a colourless layer of cells separating the epidermis from the green inner tissue (mesophyllum). If the leaves are examined under alcohol or almond oil the colourless layer is seen to be very narrow, and the thin walls of its cells shrunken and not clearly distinguishable. If the transverse sections are examined under water, these cells immediately swell up, and become strongly distended, giving off an abundance of mucilage, the latter being afforded by the solution of the very cell-walls. The mucilage of buchu leaves thus originates in the same way as in flax seed or quince seed, but in the former the epidermis is thrown off without alteration. We are not aware that other mucilaginous leaves possess a similar structure, at least not those of _Althæa officinalis_ and of _Sesamum_ which we examined[430].

=Chemical Composition=—The leaves of _B. betulina_ afforded us by distillation 1·56 per cent, of volatile oil[431], which has the odour rather of peppermint than of buchu, and deviates the ray of polarized light considerably to the left. On exposure to cold it furnishes a camphor which, after re-solution in spirit of wine, crystallizes in needle-shaped forms. After repeated purification in this manner, the crystals of _Barosma Camphor_ have an almost pure peppermint odour; they fuse at 85° C., and begin to sublime at 110° C. After fusion they again solidify only at 50° C. Submitted to elementary analysis, the crystals yielded us 74·08 per cent. of carbon and from 9 to 10 per cent. of hydrogen[432]. Barosma camphor is abundantly soluble in bisulphide of carbon.

The crude oil from which the camphor has been separated has a boiling point of about 200° C., quickly rising to 210° or even higher. That which distilled between these temperatures was treated with sodium, rectified in a current of common coal gas and submitted to elementary analysis, afforded us 77·86 per cent, of carbon and 10·58 of hydrogen. The formula C₁₀H₁₆O would require 78·94 of carbon and 10·53 of hydrogen.

Wayne’s experiments[433] appear to indicate that the oil also contains a substance capable of being converted into _salicylic acid_. An aqueous infusion of buchu leaves turns beautifully yellow if it is mixed with alkali.

[429] Flückiger in _Schweiz. Wochenschrift für Pharm._ Dec. 1873, with plate.

[430] See also Radlkofer, _Monographie der Sapindaceen-Gattung Serjania_, München, 1875, p. 100-105.

[431] Messrs. Allen and Hanburys operating on larger quantities obtained 1.63 per cent.—_Barosma serratifolia_ appears to be less rich, according to Bedford (1863).

[432] Our supply of the substance having been exhausted by two analyses we cannot regard the above figures as sufficient for the calculation of a formula.

[433] _Am. Journ. of Pharm._ 1876. 19.

On addition of perchloride of iron the infusion assumes a dingy brownish-green colour changing to red by an alkali. The infusion added to a concentrated solution of acetate of copper causes a yellow precipitate[434] which dissolves in caustic potash, affording a green solution. This may be due to the presence of a substance of the quercitrin or rutin class.