I.—PHÆNOGAMOUS OR FLOWERING PLANTS. (continued 18)

Although it was always well known that the cubebs were a product of Java and that island is stated to have exported in 1775 as much as 10,000 lb. of this spice,[2195] its mother plant was made known only in 1781 by the younger Linnæus.

The action of cubebs on the urino-genital organs was known to the old Arabian physicians. Yet modern writers on materia medica even at the commencement of the present century, mentioned the drug simply as an aromatic stimulant resembling pepper, but inferior to that spice and rarely employed,[2196]—in fact it had so far fallen into disuse that it was omitted from the London Pharmacopœia of 1809. According to Crawfurd, its importation into Europe, which had long been discontinued, recommenced in 1815, in consequence of its medicinal virtues having been brought to the knowledge of the English medical officers serving in Java, by their Hindu servants.[2197]

Cultivation and Production[2198]—Cubebs are cultivated in small special plantations and also in coffee plantations, in the district of Banjoemas in the south of Java. The fruits are bought by Chinese who carry them to Batavia. They are likewise produced in Eastern Java and about Bantam and Soebang in the north-west; and extensively in the Lampong country in Sumatra. There has of late been a large distribution of plants among the European coffee planters.

The cultivation of cubebs is easy. In the coffee estates certain trees are required for shade: against these Piper Cubeba is planted, and climbing to a height of 18 to 20 feet, forms a large bush.

Description—The cubebs of commerce consist of the dry globose fruits, gathered when full-grown, but before they have arrived at maturity. The fruit is about ⅕ of an inch in diameter, when very young sessile, but subsequently elevated on a straight thin stalk, a little longer or even twice as long as itself. By this stalk the fruit is attached in considerable numbers (sometimes more than 50) to a common thickened stalk or rachis, about 1½ inch long.

Commercial cubebs are spherical, sometimes depressed at the base, very slightly pointed at the apex, strongly wrinkled by the shrinking of the fleshy pericarp; they are of a greyish-brown or blackish hue, frequently covered with an ashy-grey bloom. The stalk is the elongated base of the fruit, and remains permanently attached. The common axis or rachis, which is almost devoid of essential oil, is also frequently mixed with the drug.

The skin of the fruit covers a hard, smooth brown shell containing the seed, which latter when developed has a compressed spherical form, a smooth surface, and adheres to the pericarp only at the base; its apex either projects slightly or is pressed inwards. The albumen is solid, whitish, oily, and encloses a small embryo below the apex. In the cubebs of the shops, the seed is mostly undeveloped and shrunken, and the pericarp nearly empty.

Cubebs have a strong, aromatic, persistent taste, with some bitterness and acridity. Their smell is highly aromatic and by no means disagreeable.

Microscopic Structure—This exhibits some peculiarities. The skin of the fruit below the epidermis, is made up of small, cubic, thick-walled cells, forming an interrupted row, and only half as large as in black pepper. The broad middle layer consists of small cubic thick-walled cells, forming an interrupted row, and only half as large as in black pepper. The broad middle layer consists of small-celled undeveloped tissue containing drops of oil, granules of starch, and crystalline groups of cubebin, probably also fat. This middle layer is interrupted by very large oil-cells, which frequently enclose needle-shaped crystals of cubebin, united in concentric groups. The much narrower inner layer consists of about four rows of somewhat larger tangentially-extended soft cells, holding essential oil. Next to these comes the light yellow brittle shell, formed of a densely packed row of encrusted, radially-arranged, elongated thick-walled cells. Lastly, the embryo is covered with a thin brown membrane, and exhibits the structure and contents as that of Piper nigrum, excepting that in P. Cubeba the cells are rounder, and the crystals consist of cubebin and not of piperin.

Chemical Composition—The most obvious constituent of cubebs is the volatile oil, the proportion of which yielded by the drug varies from 4 to 13 per cent. The causes of this great variation may be found in the constitution of the drug itself, as well as in the alterability of the oil, and the fact that its prevailing constituents begin not to boil below 264° C. It is, as shown in 1875 by Oglialoro, a mixture of an oil C₁₀H₁₆, boiling at 158°-163°, which is present to a very small amount, and two oils of the formula C₁₃H₂₄, boiling at 262°-265° C. One of the latter deviates the plane of polarization strongly to the left, and yields the crystallized compound C₁₅H₂₄ 2 HCl, melting at 118° C. The other hydrocarbon is less lævogyrate and cannot be combined with HCl.

One part of oil of cubebs, diluted with about 20 parts of bisulphide of carbon, assumes at first a greenish, and afterwards a blue coloration, if one drop of a mixture of concentrated sulphuric and nitric acids (equal weight of each acid) is shaken with the solution.

The oil distilled from old cubebs on cooling at length deposits large, transparent, inodorous octohedra of camphor of cubebs, C₃₀H₄₈ + 2 OH₂, belonging to the rhombic system. They melt at 65° and may be sublimed at 148°. We have not succeeded in obtaining them by keeping the oil of fresh cubebs for two years in contact with water, to which a little alcohol and nitric acid was added.

Another constituent of cubebs is Cubebin, crystals of which may sometimes be seen in the pericarp even with a common lens. It was discovered by Soubeiran and Capitaine in 1839; it is an inodorous substance, crystallizing in small needles or scales, melting at 125°, having a bitter taste in alcoholic solution; it dissolves freely in boiling alcohol, but is mostly deposited upon cooling; it requires 30 parts of cold ether for solution, and is also abundantly soluble in chloroform. We found this solution to be slightly lævogyre; it turns red on addition of concentrated sulphuric acid. If the solution of cubebin in chloroform is shaken with dry pentoxide of phosphorus, it turns blue and gradually becomes red by the influence of moisture. Cubebin is nearly insoluble in cold, but slightly soluble in hot water. Bernatzik (1866) obtained from cubebs 0·40 per cent. of cubebin, Schmidt (1870) 2·5 per cent. The crystals, which are deposited in an alcoholic or ethereal extract of cubebs, consist of cubebin in an impure state. Cubebin is devoid of any remarkable therapeutic action. Its composition, according to Weidel (1877) answers to the formula C₁₀H₁₀O₃; by melting it with caustic potash, cubebin is resolved as follows:—

C₁₀H₁₀O₃ · 5 O = CO₂ · C₂H₄O₂ · C₆H₃(OH)₂COOH.

Acetic Acid. Protocatechuic Acid.

The resin extracted from cubebs consists of an indifferent portion, nearly 3 per cent., and of Cubebic Acid, amounting to about 1 per cent. of the drug. Both are amorphous, and so, according to Schmidt, are the salts of cubebic acid. Bernatzik however, found some of them, as that of barium, to be crystallizable. Schulze (1873) prepared cubebic acid from the crystallized sodium-salt, but was unable to get it other than amorphous. The resins, the indifferent as well as the acid, possess the therapeutic properties of the drug.

Schmidt further pointed out the presence in cubebs, of gum (8 per cent.), fatty oil, and malates of magnesium and calcium.

Commerce—Cubebs were imported into Singapore in 1872 to the extent of 3062 cwt., of which amount 2348 cwt. were entered as from Netherlands India. The drug was re-shipped during the same year to the amount of 2766 cwt., the quantity exported to the United Kingdom being 1180 cwt., to the United States of America 1244 cwt., and to British India 104 cwt.[2199] In the previous year, a larger quantity was shipped to India than to Great Britain.

Uses—Cubebs are much employed in the treatment of gonorrhœa. The drug is usually administered in powder; less frequently in the form of ethereal or alcoholic extract, or essential oil.

Bernatzik and Schmidt, whose chemical and therapeutical experiments have thrown much light on the subject, have shown that the efficacy of cubebs being dependent on the indifferent resin and cubebic acid, preparations which contain the utmost amount of these bodies and exclude other constituents of the drug, are to be preferred. They would reject the essential oil, as they find its administration devoid of therapeutic effects.

The preparations which consequently are to be recommended, are the berries deprived of their essential oil and constituents soluble in water, and then dried and powdered; an alcoholic extract prepared from the same, or the purified resins.

Adulteration—Cubebs are not much subject to adulteration, though it is by no means rare that the imported drug contains an undue proportion of the inert stalks (rachis)[2200] that require to be picked out before the berries are ground. Dealers judge of cubebs by the oiliness and strong characteristic smell of the berries when crushed. Those which have a large proportion of the pale, smooth, ripe berries, which look dry when broken, are to be avoided.

We have occasionally found in the commercial drug a small, smooth two-celled fruit, of the size, shape, and colour of cubebs, but wanting the long pedicel. A slight examination suffices to recognize it as not being cubebs. We have also met with some cubebs of larger size than the ordinary sort, much shrivelled, with a stouter and flattened pedicel, one and a half times to twice as long as the berry. The drug has an agreeable odour different from that of common cubebs, and a very bitter taste. From a comparison with herbarium specimens, we judge that it may possibly be derived from Piper crassipes Korthals (Cubeba crassipes Miq.), a Sumatran species.

The fruits of Piper Lowong Bl. (Cubeba Lowong Miq.), a native of Java, and those of P. ribesioides Wall. (Cubeba Wallichii Miq.) are extremely cubeb-like.[2201] Those of Piper caninum A. Dietr. (Cubeba canina Miq.), a plant of wide distribution throughout the Malay Archipelago as far as Borneo, for a specimen of which we have to thank Mr. Binnendyk of Buitenzorg, are smaller than true cubebs, and have stalks only half the diameter of the berry.

In the south of China the fruits of Laurus Cubeba Lour. have been frequently mistaken by Europeans for cubebs. The tree which affords them is unknown to modern botanists; Meissner refers it doubtfully to the genus Tetranthera.[2202]

Ashantee Pepper, African Cubebs, or West African Black Pepper.

This spice is the fruit of Piper Clusii Cas. DC. (Cubeba Clusii Miq.), a species of wide distribution in tropical Africa, most abundantly occurring in the country of the Niamniam, about 4° to 5° N. lat., and 28° to 29° E. long. Its splendid red fruit bunches are spoken of with admiration by Schweinfurth,[2203] who states that Piper Clusii is one of the characteristic and most conspicuous plants of those regions. The dried fruit is a round berry having a general resemblance to common cubebs but somewhat smaller, less rugose, attenuated into a slender pedicel once or twice as long as the berry and usually curved. The berries are crowded around a common stalk or rachis; they are of an ashy-grey tint, and have a hot taste and the odour of pepper. According to Stenhouse, they contain piperin and not cubebin.[2204]

The fruit of Piper Clusii was known as early as 1364 to the merchants of Rouen and Dieppe, who imported it from the Grain Coast, now Liberia,[2205] under the name of pepper. The Portuguese likewise exported it from Benin as far back as 1485, as Pimienta de rabo, i.e. tailed pepper, and attempted in vain to sell it in Flanders.[2206] Clusius received from London a specimen of this drug, of which he has left a good figure in his Exotica.[2207] He says that its importation was forbidden by the King of Portugal for fear it should depreciate the pepper of India. The spice was also known to Gerarde and Parkinson; in our times it has been afresh brought to notice by the late Dr. Daniell.[2208] In tropical Western Africa it is used as a condiment, and might easily be collected in large quantities, provided it should prove a good substitute for pepper.[2209]

HERBA MATICO.

Matico.

Botanical Origin—Piper angustifolium [2210]

History—The styptic properties of this plant are said to have been discovered by a Spanish soldier named Matico,[2211] who having applied some of the leaves to his wounds, observed that the bleeding was thereby arrested; hence the plant came to be called Yerba or Palo del Soldado (soldier’s herb or tree). The story is not very probable, but it is current in many parts of South America, and its allusion is not confined to the plant under notice.

The hæmostatic powers of matico, which are not noticed in the works of Ruiz and Pavon, were first recognized in Europe by Jeffreys,[2212] a physician of Liverpool, in 1839, but they had already attracted attention in North America as early as 1827.

Description—Matico, as it arrives in commerce, consists of a compressed, coherent, brittle mass of leaves and stems, of a light green hue and pleasant herby odour. More closely examined, it is seen to be made up of jointed stems bearing lanceolate, acuminate leaves, cordate and unequal at the base, and having very short stalks. The leaves are rather thick, with their whole upper surface traversed by a system of minute sunk veins, which divide it into squares and give it a tessellated appearance. On the under side, these squares form a corresponding series of depressions which are clothed with shaggy hairs. The leaves attain a length of about 6 inches by 1½ inches broad. The flower and fruit spikes which are often 4 to 5 inches long, are slender and cylindrical with the flowers or fruits densely packed. The leaves of matico have a bitterish aromatic taste; their tissue shows numerous cells, filled with essential oil.[2213]

Chemical Composition—The leaves yield on an average 27 per cent.[2214] of essential oil, which we find slightly[2215] dextrogyre; a large proportion of it distills at 180° to 200° C., the remainder becoming thickish. Both portions are lighter than water; but another specimen of the oil of matico which we had kept for some years, sinks in water. We have observed that in winter the oil deposits remarkable crystals of a camphor, more than half an inch in length, fusible at 103° C.; they belong to the hexagonal system, and have the odour and taste of the oil from which they separate.

Matico further affords, according to Marcotte (1864),[2216] a crystallizable acid, named Artanthic Acid, besides some tannin. The latter is made evident by the dark brown colour which the infusion assumes on addition of ferric chloride. The leaves likewise contain resin, but as shown by Stell in 1858, neither piperin, cubebin, nor any analogous principle such as the so-called Maticin formerly supposed to exist in them.

Commerce—The drug is imported in bales and serons by way of Panama. Among the exports of the Peruvian port of Arica in 1877, we noticed 195 quintales (19,773 lb) of Matico.

Uses—Matico leaves, previously softened in water, or in a state of powder, are sometimes employed to arrest the bleeding of a wound. The infusion is taken for the cure of internal hæmorrhage.

Substitutes—Several plants have at times been brought into the market under the name of matico. One of these is Piper aduncum L.[2217] (Artanthe adunca Miq.), of which a quantity was imported into London from Central America in 1863, and first recognized by Bentley (1864). In colour, odour, and shape of leaf it nearly agrees with ordinary matico; but differs in that the leaves are marked beneath by much more prominent ascending parallel nerves, the spaces between which are not rugose but comparatively smooth and nearly glabrous. In chemical characters, the leaves of P. aduncum appear to accord with those of P. angustifolium.

Piper aduncum is a plant of wide distribution throughout Tropical America. Under the name of Nhandi or Piper longum it was mentioned by Piso in 1648[2218] on account of the stimulant action of its leaves and roots,—a property which causes it to be still used in Brazil, where however no particular styptic virtues seem to be ascribed to it.[2219] The fruits are there employed in the place of cubebs. Sloane’s figure[2220] of “Piper longum, arbor folio latissimo” also shows Piper aduncum.

According to Triana, Piper lanceæfolium HBK. (Artanthe Miq.), and another species not recognized, yield matico in New Granada.[2221] Waltheria glomerata Presl (Sterculiaceæ) is called Palo del Soldado at Panama and its leaves are used as a vulnerary.[2222] In Riobamba and Quito, Eupatorium glutinosum Lamarck, is also called Chusalonga or Matico.[2223]

ARISTOLOCHIACEÆ.

RADIX SERPENTARIÆ.

Radix Serpentariæ Virginianæ; Virginian Snake-root, Serpentary Root; F. Serpentaire de Virginie; G. Schlangenwurzel.

Botanical Origin—Aristolochia Serpentaria L., a perennial herb, commonly under a foot high, with simple or slightly branched, flexuose stems, producing small, solitary, dull purple flowers, close to the ground. It grows in shady woods in the United States, from Missouri and Indiana to Florida and Virginia,—abundantly in the Alleghanies and in the Cumberland Mountains, less frequently in New York, Michigan and the other Northern States. The plant varies exceedingly in the shape of its leaves.

History—The botanists of the 16th century, being fond of appellations alluding to the animal kingdom, gave the names of Serpentaria or Colubrina, i.e. snake-root, to the rhizome of Polygonum Bistorta L. In America it was not the appearance, but the application of the drug under notice to which it owes the name snake-root.

The earliest account of Virginian snake-root is that of Thomas Johnson, an apothecary of London who published an edition of Gerarde’s Herbal in 1636. It is evident however that Johnson confounded a species of Aristolochia from Crete with what he calls “that snake-weed that was brought from Virginia and grew with Mr. John Tradescant at South Lambeth, anno 1632.” It was very briefly noticed by Cornuti in his Canadensium Plantarum Historia (1635), and in a much more intelligent manner by Parkinson in 1640. These authors, as well as Dale (1693) and Geoffroy (1741), extol the virtues of the root as a remedy for the bite of the rattlesnake, or of a rabid dog. Serpentary was introduced into the London Pharmacopœia in 1650.

Description—The snake-root of commerce includes the rhizome, which is knotty, contorted, scarcely 1 inch in length by ⅛ of an inch in thickness, bearing on its upper side the short bases of the stems of previous years, and throwing off from the under, numerous, slender, matted, branching roots, 2 to 4 inches long. The rhizome is often still attached to portions of the weak, herbaceous stem, which sometimes bears the fruit,—more rarely flowers and leaves. The drug has a dull brown hue, an aromatic odour resembling valerian but less unpleasant, and a bitterish aromatic taste, calling to mind camphor, valerian and turpentine.

Microscopic Structure—In the rhizome, the outer layer of the bark consists of a single row of cuboid cells; the middle cortical portion (mesophlœum) of about six layers of larger cells. In the liber, which is built up of numerous layers of smaller cells, those belonging to the medullary rays are nearly cuboid with distinctly porous walls, those of the liber bundles being smaller and arranged in a somewhat crescent-shaped manner. Groups of short, reticulated or punctuated vessels alternate in the woody rays with long, porous, ligneous cells; those close to the pith having thick walls. The largest cells of all are those composing the pith; the latter, seen in transverse section, occupies not the very centre of the rootstock, but is found nearer to its upper side. The rootlets exhibit a central fibro-vascular bundle, surrounded by a nucleus-sheath. In the mesophlœum both of the rootstock and the rootlets, there occur a few cells containing a yellow essential oil. The other cells are loaded with starch.

Chemical Composition—Essential oil exists in the drug to the extent of about ½ per cent.; and resin in nearly the same proportion. The outer cortical layer, as well as the zone of the nucleus-sheath, contains a little tannin, and a watery infusion of the drug is coloured greenish by perchloride of iron. Neutral acetate of lead precipitates some mucilage as well as the bitter principle, which latter may also be obtained by means of tannic acid. It is an amorphous, bitter substance, which deserves further investigation. By an alkaline solution of tartrate of copper the presence in serpentary of sugar is made evident.

Commerce—Virginian snake-root is imported from New York and Boston, in bales, casks or bags.

Uses—The drug is employed in the form of an infusion or tincture as a stimulating tonic and diaphoretic; it is more often prescribed in combination with cinchona bark than by itself. Its ancient reputation for the cure of snake-bites is now disregarded.

Adulteration and Substitution—Virginian snake-root is said to be sometimes adulterated with the root of Spigelia marilandica L., which has neither its smell nor taste (see p. 433); or with that of Cypripedium pubescens L., which it scarcely at all resembles. It is not uncommon to find here and there in the serpentary of commerce, a root of Panax quinquefolium L. accidentally collected, but never added for the purpose of adulteration.

The root of Aristolochia reticulata Nutt., a plant of Louisiana and Arkansas, has been brought into commerce in considerable quantity as Texan or Red River Snake-root.[2224] We are indebted for an authentic specimen from the Cherokee country to Mr. Merrell, a large dealer in herbs at St. Louis, Missouri, who states that all the serpentary grown south-west of the Rocky Mountains is the produce of that species. The late Prof. Parrish of Philadelphia was kind enough to supply us with specimens of the same drug, as well as with reliable samples of true Virginian or Middle States Snake-root.

The Texan snake-root is somewhat thicker and less matted than that derived from A. Serpentaria, but has the odour and taste of the latter; some say it is less aromatic. The plant, portions of which are often present, may be easily distinguished by its leaves being coriaceous, sessile and strongly reticulated on their under surface.

CUPULIFERÆ.

CORTEX QUERCUS.

Oak Bark; F. Ecorce de Chêne; G. Eichenrinde.

Botanical Origin—Quercus Robur L., a tree, native of almost the whole of Europe, from Portugal and the Greek Peninsula as far north as 58° N. lat. in Scotland, 62° in Norway, and 56° in the Ural Mountains.

There are two remarkable forms of this tree which are regarded by many botanists as distinct species, but which are classed by De Candolle[2225] as sub-species.

Sub-species I. pedunculata—with leaves sessile or shortly stalked, and acorns borne on a long peduncle, and acorns either sessile or growing on a short peduncle.

Sub-species II. sessiliflora—with leafstalks more or less elongated.

Both forms occur in Britain. The first is the common oak of the greater part of England and the lowlands of Scotland. The second is frequently scattered in woods in which the first variety prevails, but it rarely constitutes the mass of the oak woods in the south of England. In North Wales however, in the hilly parts of the north of England, and in Scotland, it is the commoner of the two forms (Bentham).

History—The astringent properties of all parts of the oak[2226] were well known to Dioscorides, who recommends a decoction of the inner bark in colic, dysentery and spitting of blood. Yet oak bark seems at no time to have been held in great esteem as a medicine, probably on account of its commonness; and it is now almost superseded by other astringents. For tanning leather it has always been largely employed.

Description—For medicinal use the bark of the younger stems or branches is collected in the early spring. It varies somewhat in appearance according to the age of the wood from which it has been taken: that usually supplied to English druggists is in channelled pieces of variable length and a tenth of an inch or less in thickness, smooth, of a shining silvery grey, variegated with brown, dotted over with little scars. The inner surface is light rusty-brown, longitudinally striated. The fracture is tough and fibrous. A transverse section shows a thin, greenish cork-layer, within which is the brown parenchyme, marked with numerous rows of translucent colourless spots. The smell of dry oak bark is very faint; but when the bark is moistened the odour of tan becomes evident. The taste is astringent and in old barks slightly bitter.

Microscopic Structure—The outer layer of young oak bark consists of small flat cork-cells; the middle layer of larger thick-walled cells slightly extended in a tangential direction, and containing brown grains and chlorophyll. This tissue passes gradually into the softer narrower parenchyme of the inner bark, which is irregularly traversed by narrow medullary rays. It exhibits moreover a ring, but slightly interrupted, of thick-walled cells (sclerenchyme) and isolated shining bundles of liber-fibres.

Groups of crystals of calcium oxalate are frequent in the middle and inner bark, but the chief constituents of the cells are brown granules of colouring matter and tannin. As the thickness of the bark increases the liber is pushed more to the outside, the middle cortical layer being partly thrown off by secondary cork-formation (rhytidoma, see pp. 354 and 538). Hence the younger barks, which alone are medicinal, are widely different from the older in structure and appearance.

Chemical Composition—The most interesting constituent is a peculiar kind of tannin. Stenhouse pointed out in 1843 that the tannic acid of oak bark is not identical with that of nutgalls; and such many years afterwards was proved to be the case.

The first-named substance, now called Querci-tannic Acid, yields by destructive distillation pyrocatechin, and according to Johanson (1875) very little pyrogallol. By boiling it with dilute sulphuric acid querci-tannic acid is split up into a red derivative and sugar. A solution of gelatine is precipitated by querci-tannic acid as well as by gallo-tannic acid; yet the compound formed with the latter is very liable to putrefaction, whereas the tannin of oak bark, which is accompanied by a large amount of extractive matter, furnishes a stable compound, and is capable of forming good leather.

As querci-tannic acid has not yet been isolated in a pure state, the exact estimation of the strength of the tanning principle in oak bark has not been accomplished, although it is important from an economic as well as from a scientific point of view. The method of Neubauer (1873) depends upon the amount of permanganate of potassium decomposable by the extract of a given weight of oak bark. Neubauer found in the bark of young stems, as grown for tanning purposes, from 7 to 10 per cent. of querci-tannic acid, soluble in cold water.

Braconnot (1849) extracted from the seeds of the oaks under notice a crystallized sugar, which was shown in 1851 by Dessaignes to be a peculiar substance, which he termed Quercite. Prunier proved (1877-1878) that it agrees with the formula C₆H₇(OH)₅ + 4 OH₂, and is closely allied to kinic acid, C₆H₇(OH)₄COOH (see page 363). Quercite gives off water at 100°, melts at 225° C., and again losing water yields a crystallized anhydride. In the oak bark extremely small quantities of quercite appear also to be present, as pointed out by Johanson.

A colourless, crystallizable, bitter substance, soluble in water, but not in absolute alcohol or ether, was extracted from oak bark in 1843 by Gerber, and named Quercin. It requires further examination: Eckert (1864) could not detect its existence in young oak bark.

Uses—Occasionally employed as an astringent, chiefly for external application.

GALLÆ HALEPENSES.

Gallæ Turcicæ; Galls, Nutgalls, Oak Galls, Aleppo or Turkey Galls; F. Noix de Galle, Galle d’Alep; G. Levantische oder Aleppische Gallen, Galläpfel.

Botanical Origin—Quercus lusitanica Webb, var. infectoria (Q. infectoria Oliv.),[2227] a shrub or rarely a tree, found in Greece, Asia Minor, Cyprus and Syria. It is probable that other varieties of this oak, as well as allied species, contribute to furnish the Aleppo galls of commerce.

History—Oak galls are named by Theophrastus, and were well known to other ancient writers. Alexander Trallianus prescribed them as a remedy in diarrhœa.[2228]

The earliest accurate descriptions and figures of the oak and the insect producing the galls are due to Olivier.[2229] Pliny[2230] mentions the interesting fact that paper saturated with an infusion of galls may be used as a test for discovering sulphate of iron, when added as an adulteration to the more costly verdigris: this, according to Kopp, is the earliest instance of the scientific application of a chemical reaction.[2231] For tanning and dyeing, galls have been used from the earliest times, during the middle ages however they were not precisely an article of great importance, being then, no doubt, for a large part replaced by sumach.

Nutgalls have long been an object of commerce between Western Asia and China. Barbosa in his Description of the East Indies[2232] written in 1514 calls them Magican,[2233] and says they are brought from the Levant to Cambay by way of Mekka, and that they are worth a great deal in China and Java. From the statements of Porter Smith[2234] we learn that they are still prized by the Chinese.

Formation—Many plants are punctured by insects for the sake of depositing their eggs, which operation gives rise to those excrescences which bear the general name of gall.[2235]

Oaks are specially liable to be visited for this purpose by insects of the order Hymenoptera and the genus Cynips, one species of which, Cynips Gallæ tinctoriæ Olivier (Diplolepis Gallæ tinctoriæ Latreille), occasions the galls under notice.

The female of this little creature is furnished with a delicate borer or ovipositor, which she is able to protrude from the extremity of the abdomen; by means of it she pierces the tender shoot of the oak, and deposits therein one or more eggs. This minute operation occasions an abnormal affluence to the spot of the juices of the plant, the result of which is the growth of an excrescence often of great magnitude, in the centre of which (but not as it appears until the gall has become full-grown) the larva is hatched and undergoes its transformations.

When the larva has assumed its final development and become a winged insect, which requires a period of five to six months, the latter bores itself a cylindrical passage from the centre of the gall to its surface, and escapes.

In the best kind of gall found in commerce, this stage has not yet arrived, the gall having been gathered while the insect is still in the larval state. In splitting a number of galls, it is not difficult to find specimens in all stages, from those containing the scarcely distinguishable remains of the minute larva, to those which show the perfect insect to have perished when in the very act of escaping from its prison.

Description—Aleppo galls[2236] are spherical, and have a diameter of ⁴/₁₀ to ⁸/₁₀ of an inch. They have a smooth and rather shining surface, marked in the upper half of the gall by small pointed knobs and ridges, arranged very irregularly and wide apart; the lower half is more frequently smooth. The aperture by which the insect escapes is always near the middle. When not perforated, the galls are of a dark olive green, and comparatively heavy; but after the fly has bored its way out, they become of a yellowish-brown hue, and lighter in weight. Hence the distinction in commerce of Blue or Green Galls, and White Galls.

Aleppo galls are hard and brittle, splitting under the hammer; they have an acidulous, very astringent taste followed by a slight sweetness, but have no marked odour. Their fractured surface is sometimes close-grained, with a waxy or resinous lustre; sometimes (especially towards the kernel-like centre) loosely granular, or sometimes again it exhibits a crystalline-looking radiated structure or is full of clefts. The colour of the interior varies from pale brown to a deep greenish yellow. The central cavity, sometimes nearly ¼ of an inch in diameter, which served as a dwelling for the insect, is lined with a thin hard shell. If the insect has perished while still very young, the central cavity and the aperture contain a mass of loose starchy cellular tissue, or its pulverulent remains: if the insect has not been developed at all, the centre of the gall is entirely composed of this tissue.

Microscopic Structure—The cellular tissue of the gall is formed in the middle layer of large spherical cells with rather thick porous walls, becoming considerably smaller towards the circumference. The outermost rows are built up of cells having but a very small lumen and comparatively thick walls, so that they form a sort of rind. Here and there throughout the entire tissue, there occur isolated bundles of vessels which pass through the stalk into the gall. Towards the kernel, the parenchyme gradually passes into radially-extended, wider, thin-walled cells, the walls of which are marked with spiral striæ. The hard shell of the chamber[2237] is composed of larger, radially-extended, thick-walled cells, with beautifully stratified porous walls. On the inner side of this shell there are found, after the escape of the insect, the remains of the starchy tissue already mentioned, which originally filled the chamber and had been consumed by the insect as nourishment.

The parenchyme-cells outside the shell contain chlorophyll and tannin; the latter is in transparent, colourless, sharp-edged masses, insoluble in benzol, but dissolving slowly in water, quickly in alcohol. Thin slices soaked in glycerin appear after some time covered with beautiful crystals of gallic acid. The thick-walled cells (stone-cells) and the neighbouring striated cells, are rich in octahedra of calcium oxalate. The tissue of the gall situated within the shell of thick-walled cells contains starch in large, compressed, mostly spherical granules; also isolated masses of brown resin. Besides these, there appears to be in this part of the tissue an albuminoid compound.

Chemical Composition—The rough taste of galls is due to their chief constituent, Tannic or Gallo-tannic Acid, C₁₄H₁₀O₉, or

C₆H₂(OH)₂COOH O,

C₆H₂(OH)₂CO

the type of a numerous family of substances to which vegetables owe their astringent properties. Tannic matter was long supposed to be of one kind, namely that found in the oak gall, but the researches of later years have proved the tannin of different plants to possess distinctive characters: hence the term gallo-tannic acid to distinguish that of galls, from which it is principally derived. It was however shown by Stenhouse as far back as the year 1843, again in 1861, as well as by still more recent unpublished experiments, that the tannic acid found in Sicilian sumach, the leaves of Rhus Coriaria L., is identical with that of oak galls. Löwe in 1873 came to the same conclusion. The best oak galls yield of this acid, from 60 to 70 per cent.

Gallic Acid is also contained in galls ready-formed to the extent of about 3 per cent. Free sugar, resin, protein-substances, have also been found. Neither gum nor dextrin is present.

Commerce—The introduction into dyeing of new chemical substances, and the increased employment of sumach and myrobalans, have caused the trade in nutgalls to decline considerably during the last few years. The province of Aleppo which used to export annually 10,000 to 12,000 quintals, exported in 1871 only 3000 quintals.[2238] A staple market for the galls which are collected in the mountains of Kurdistan is Diarbekir, whence they are sent to Trebizond for shipment. Galls are also shipped in some quantity at Bussorah, Bagdad, Bushire, and Smyrna.

There were imported into the United Kingdom from ports of Turkey and Persia during 1872, 6349 cwt. of galls, valued at £18,581.

Uses—Oak galls in their crude state are seldom used in medicine unless it be externally; but the tannic and gallic acids extracted from them are often administered.

Other kinds of Gall.

Chinese or Japanese Galls—The only kind of galls, besides those of the oak, which are of commercial importance. They are described at page 167.

Pistacia Galls—The genus Pistacia, which belongs to the same order as Rhus, is very liable to the attacks of Aphis, which produce upon its leaves and branches excrescences of exactly the same nature as Chinese galls. In the south of Europe, horn-like follicles, often several inches long,[2239] are frequently met with on the branches of Pistacia Terebinthus (page 165). These Gallæ vel Folliculi Pistacinæ, in Italian Carobbe di Giudea, were formerly used in medicine and in dyeing.[2240] They were noticed in 1555 by Belon, but already well known as early as the time of Theophrastus.

Another much smaller gall of different shape is formed (by the same insect?) on the ribs of the leaves of Pistacia Terebinthus; P. Lentiscus (page 161) affords also a similar small excrescence.

Again, another growth of the same character constitutes the small and very astringent galls known in the Indian bazaars by the names of Bazghanj and Gule-pistah, the latter signifying flower of pistachio; they have been termed in Europe Bokhara Galls. They were imported by sea into Bombay in the year 1872-73, to the extent of 184 cwt., chiefly from Sind;[2241] and are also carried into North-western India by way of Peshawar and by the Bolan Pass. Occasionally a package finds its way into a London drug sale.

Tamarisk Galls—These are roundish knotty excrescences of the size of a pea up to ½ an inch in diameter, found in North-western India on the branches of Tamarix orientalis L., a large, quick-growing tree, common on saline soils. The galls are used in India in the place of oak galls, and are mentioned as “non-officinal” in the Pharmacopœia of India, 1867. We are not aware that they have been the subject of any particular chemical research; their microscopic structure has been investigated by Vogl.[2242]

SANTALACEÆ.

LIGNUM SANTALI.

Lignum Santalinum album vel citrinum; Sandal-wood; F. Bois de Santal citrin; G. Weisses oder Gelbes Sandelholz.

Botanical Origin—Santalum album[2243] L., a small tree, 20 to 30 feet high, with a trunk 18 to 35 inches in girth, a native of the mountainous parts of the Indian peninsula, but especially of Mysore and parts of Coimbatore and North Canara, in the Madras Presidency; it grows in dry and open places, often in hedge-rows, not in forests. The same tree is also found in the islands of the Eastern Archipelago, notably of Sumba (otherwise called Chandane or Sandal-wood Island), and Timur.

In later times, sandal-wood has been extensively collected in the Hawaiian or Sandwich Islands, where its existence was first pointed out about the year 1778, from Santalum Freycinetianum Gaud. and S. pyrularium A. Gray;[2244] in the Viti or Fiji Islands from S. Yasi Seem.; in New Caledonia from S. austro-caledonicum, Vieill;[2245] and in Western Australia from Fusanus spicatus Br. (Santalum spicatum DC., S. cygnorum Miq.).[2246] The mother plants of Japanese and West Indian sandal-wood are not known to us.

In India the sandal-wood tree is protected by Government, and is the source of a profitable commerce. In other countries it has been left to itself, and has usually been extirpated, at least from all accessible places, within a few years of its discovery.

History—Sandal-wood, the Sanskrit name for which, Chandana, has passed into many of the languages of India, is mentioned in the Nirukta or writings of Yaska, the oldest Vedic commentary extant, written not later than the 5th century b.c. The wood is also referred to in the ancient Sanskrit epic poems, the Rāmāyana and Mahabharata, parts of which may be of nearly as early date.

The author of the Periplus of the Erythrean Sea, written about the middle of the 1st century, enumerates sandal-wood (Ξύλα σαγαλίνα) among the Indian commodities imported into Omana in the Persian Gulf.[2247]

The Τζανδάνα mentioned towards the middle of the 6th century by Cosmas Indicopleustes,[2248] as brought to Taprobane (Ceylon) from China and other emporia, was probably the wood under consideration. In Ceylon its essential oil was used as early as the 9th century in embalming the corpses of the princes.

Sandal-wood is named by Masudi[2249] as one of the costly aromatics of the Eastern Archipelago. In India it was used in the most sacred buildings, of which a memorable example still exists in the famous gates of Somnath, supposed to be 1000 years old.[2250]

In the 11th century sandal-wood was found among the treasures of the Egyptian khalifs, as stated in our article on camphor at page 511.

Among European writers, Constantinus Africanus, who flourished at Salerno in the 11th century, was one of the earliest to mention Sandalum.[2251] Ebn Serabi, called Serapion the Younger, who lived about the same period, was acquainted with white, yellow, and red sandal-wood.[2252] All three kinds of sandal-wood also occur in a list of drugs[2253] in use at Frankfort, circa a.d. 1450; and in the Compendium Aromatariorum of Saladinus, published in 1488, we find mentioned as proper to be kept by the Italian apothecary,—“Sandali trium generum, scilicet albi, rubii et citrini.”

Whether the red sandal here coupled with white and yellow was the inodorous wood of Pterocarpus santalinus, now called Lignum santalinum rubrum or Red Sanders (see p. 199), is extremely doubtful. It may have meant real sandal wood, of which three shades, designated white, red, and yellow, are still recognized by the Indian traders.[2254]

On the other hand, we learn from Barbosa[2255] that about 1511 white and yellow sandal-wood were worth at Calicut on the Malabar Coast from eight to ten times as much as the red, which would show that in his day the red was not a mere variety of the other two, but something far cheaper, like the Red Sanders Wood of modern commerce.

In 1635 the subsidy levied on sandal-wood imported into England was 1s. per lb. on the white, and 2s. per lb. on the yellow.[2256]

The first figure and satisfactory description of Santalum album occur in the Herbarium Amboinense of Rumphius (ii. tab. 11).

Production—The dry tracts producing this valuable wood occupy patches of a strip of country lying chiefly in Mysore and Coimbatore, about 250 miles long, north and north-west of the Neilgherry Hills, and having Coorg and Canara between it and the Indian Ocean; also a piece of country further eastward in the districts of Salem and North Arcot, where the tree grows from the sea-level up to an elevation of 3000 feet. In Mysore, where sandal-wood is most extensively produced, the trees all belong to Government, and can only be felled by the proper officers. This privilege was conferred on the East India Company by a treaty with Hyder Ali, made 8 August 1770, and the monopoly has been maintained to the present day. The Mysore animal exports of sandal wood are about 700 tons, valued at £27,000.[2257] They are shipped from Mangalore.

A similar monopoly existed in the Madras Presidency until a few years ago, when it was abandoned. But sandal-wood is still a source of revenue to the Madras Government, which by the systematic management of the Forest Department has of late years been regularly increasing. The quantity of sandal-wood felled in the Reserved Forests during the year 1872-3 was returned as 15,329 maunds (547½ tons).[2258]

The sandal-wood tree, which is indigenous to the regions just mentioned, used to be reproduced by seeds sown spontaneously or by birds; but it is now being raised in regular plantations, the seeds being sown two or three in a hole with a chili (Capsicum) seed, the latter producing a quick-growing seedling which shades the sandal while young.[2259] It is probable that the nurse-plant affords sustenance, for it has been shown[2260] that Santalum is parasitic, its roots attaching themselves by tuber-like processes to those of many other plants; and it is also said that young sandal plants thrive best when grass is allowed to grow up in the seed-beds.

The trees attain their prime in 20 to 30 years, and have then trunks as much as a foot in diameter. A tree having been felled, the branches are lopped off, and the trunk allowed to lie on the ground for several months, during which time the white ants eat away the greater part of the inodorous sapwood. The trunk is then roughly trimmed, sawn into billets 2 to 2½ feet long, and taken to the forest depots. There the wood is weighed, subjected to a second and more careful trimming, and classified according to quality. In some parts it is customary not to fell but to dig the tree up; in others the root is dug up after the trunk has been cut down,—the root affording valuable wood, which with the chips and sawdust are preserved for distillation, or for burning in the native temples. The sap wood and branches are worthless.[2261]

In 1863 a sort of sandal-wood afforded by Fusanus spicatus (p. 599) was one of the chief exports of Western Australia, whence it was shipped to China. A trifling payment for permission to cut growing timber of any kind was the only barrier placed on the felling of the trees. The farmers employed their teams during the dull season in bringing to Perth or Guildford the logs of sandal which had been felled and trimmed in the bush; and there was a flourishing trade so long as trees of a fair size could be obtained within 100 or even 150 miles of the towns, where the commodity was worth £6 to £6 10s. per ton. But the ill-regulated and improvident destruction of the trees in the more easily accessible districts has so reduced their numbers that the trade in that part of Australia soon came to an end.[2262] Australian sandal-wood appears however to be still an article of commerce, if one may draw such an inference from the fact that 47,904 cwt. of sandal wood were imported into Singapore from Australia in the year 1872. It was mostly re-shipped to China.[2263]

Description—sandal-wood is not much known in English commerce, and is by no means always to be found even in London. That which we have examined, and which we believe was Indian, was in cylindrical logs, mostly about 6 inches in diameter (the largest 8 inches—smallest 3: inches) and 3 to 4 feet long, extremely ponderous; the bark had been removed. A transverse section of sandal-wood exhibits it of a pale brown, marked with rather darker concentric zones and (when seen under a lens) numerous open pores. The tissue is traversed by medullary rays, also perceptible by the aid of a lens. The wood splits easily, emitting when comminuted an agreeable odour which is remarkably persistent; it has a strongish aromatic taste.

The varieties of sandal-wood are not classified by the few persons who deal in the article in London, and we are unable to point out characters by which they may be distinguished. In the price-currents of commercial houses in China three sorts of sandal-wood are enumerated, namely, South Sea Island, Timor, and Malabar; the last fetches three or four times as high a price as either of the others. Even the Indian sandal-wood may vary in an important manner. Beddome,[2264] conservator of forests in Madras, and an excellent observer, remarks that the finest sandal-wood is that which has grown slowly on rocky, dry and poor land; and that the trees found in a rich alluvial soil, though of very fine growth, produce no heartwood and are consequently valueless. A variety of the tree with more lanceolate leaves (var. β myrtifolium DC.), native of the eastern mountains of the Madras Presidency, affords a sandal-wood which is nearly inodorous.

Microscopic Structure—The woody rays or wedges show a breadth varying from 35 to 420 mkm., the primary being frequently divided by secondary medullary rays. These latter rays consist of one, often of two, rows of cells of the usual form. The woody tissue which they enclose is chiefly made up of small ligneous fibres with pointed ends, some larger parenchymatous cells, and thick-walled vessels. The resin and essential oil reside chiefly in the medullary rays, as shown by the darker colour of these latter.

Chemical Composition—The most important constituent is the essential oil, which the wood yields to the extent of from 2 to 5 per cent.[2265] In India, with imperfect stills, 2·5 per cent. of the oil are obtained; the roots yield the largest amount and the finest quality of it.[2266] It is a light yellow, thick liquid, possessing the characteristic odour of sandal; that which we examined had a sp. gr. of 0·963. We did not succeed in finding a fixed boiling point of the oil; it began to boil at 214° C., but the temperature quickly rose to 255°, the oil acquiring a darker hue. Oil of sandal-wood varies much in the strength and character of its aroma, according to the sort of wood from which it is produced.

The oil as largely prepared by Messrs. Schimmel & Co., in a column 100 millimetres long, deviates the plane of polarization 18·6° to the left. Oil of Venezuela sandal-wood, from the same distillers, examined in the same manner, deviates 6°·75 to the right.

From the wood, treated with boiling alcohol, we obtained about 7 per cent. of a blackish extract, from which a tannate was precipitated by alcoholic solution of acetate of lead. Decomposed by sulphuretted hydrogen, the tannate yielded a tannic acid having but little colour, and striking a greenish hue with a ferric salt. The extract also contained a dark resin.

Commerce—The greatest trade in sandal-wood is in China, which country in the year 1866 imported at the fourteen treaty ports then open 87,321 peculs, equivalent to 5,197 tons; of this vast quantity the city of Hankow on the river Yangtsze, received no less than 61,414 peculs, or more than seven times as much as any other port.[2267] The imports into Hankow have recently been much smaller, namely, 14,989 peculs in 1871 and 12,798 peculs in 1872.[2268] On the other hand, Shanghai lying near the mouth of the same great river, imported in 1872, 59,485 peculs of sandal-wood, the estimated value of which was about £100,000. In 1877 the imports of all China were 72,934 peculs.

A considerable trade in sandal-wood is done in Bombay, the quantity imported thither annually being about 650 tons, and the animal export about 400 tons.[2269]

Oil of sandal-wood is largely manufactured on the ghats between Mangalore and Mysore, where fuel for the stills is abundant. Official returns[2270] represent the quantity of the oil imported into Bombay in the year 1872-73 as 10,348 lbs., value £8,374; 4,500 lbs. were re-exported by sea.

Uses—The essential oil has of late been prescribed as a substitute for copaiba, otherwise sandal-wood has hardly any uses in modern European medicine. It is employed as a perfume and for the fabrication of small articles of ornament. Among the natives of India it is largely consumed in the celebration of sepulchral rites, wealthy Hindus showing their respect for a departed relative by adding sticks of sandal-wood to the funereal pile. The powder of the wood made into a paste with water is used for making the caste mark, and also for medicinal purposes. The consumption of sandal-wood in China appears to be principally for the incense used in the temples.

Gymnosperms.

CONIFERÆ.

TEREBINTHINA VULGARIS.

Crude or Common Turpentine; F. Térebenthine commune; G. Gemeiner Terpenthin.

Botanical Origin—The trees which yield Common Turpentine may be considered in two groups, namely, European and American.

1. European—In Finland and Russia Proper, the Scotch Pine, Pinus sivestris L.; in Austria and Corsica, P. Laricio Poiret; and in South-western France, P. Pinaster Solander (P. maritima Poiret), extensively cultivated as the Pin maritime, yield turpentine in their respective countries.

2. American—In the United States, the conifers most important for terebinthinous products are the Swamp Pine, Pinus australis Michaux (P. palustris Mill.), and the Loblolly Pine, P. Tæda L.

History—The resin of pines and firs was well known to the ancients, who obtained it in much the same manner as that practised at the present day. The turpentine used in this country has for many years past been derived from North America. Up to the last century, both it and the substance called Common Frankincense were imported from France. The late civil war in the United States and the blockade of the Southern ports, occasioned a great scarcity of American turpentine; and terebinthinous substances from all other countries were poured into the London market. The actual supplies, however, were mainly furnished by France.

Kopp[2271] quotes a passage showing that the essential oil of turpentine was known to Marcus Græcus, who termed it Aqua ardens. This almost unknown personage is the reputed inventor of Greek Fire, a dreaded engine of destruction in mediæval warfare.

Secretion—The primary formation of resin-ducts in the bark of coniferous trees has been explained by Dippel,[2272] Müller,[2273] and Frank.[2274] The subsequent diffusion of the resinous juice through the heartwood, sapwood, and bark, has been elaborately investigated by Hugo von Mohl.[2275] From the various forms under which this diffusion exists in the different species have arisen the diverse methods of obtaining the terebinthinous resins.

Thus in the wood of the Silver Fir (Pinua Picea L.) resin-ducts are altogether wanting;—and led by experience, the Alpine peasant collects the turpentine of this tree by simply puncturing the little cavities which form under its bark. In the Scotch Pine (P. silvestris L.), they are more abundant in the wood than in the bark, a fact which might be anticipated by observing how rarely this tree exudes resin spontaneously.

Oil of turpentine, like volatile oils in general, undergoes on exposure to the air certain alterations giving rise to what is called resinification. The formic acid which is produced in small quantity during this change characterizes it as one of oxidation; the chief products however are not exactly known, and not one of them has been proved identical with any natural resin. The common assumption that resins are produced from volatile oils by simple oxidation, is consequently not yet entirely justified.

Extraction—In the United States[2276] turpentine is obtained to the largest extent from Pinus australis, of which tree there are vast forests, the piny woods or pine-barrens, extending from Virginia to the Mexican Gulf, especially through North and South Carolina, Georgia and Alabama. But it is in North Carolina that the extraction of turpentine is principally carried on.

In the winter, i.e. from November to March, the negroes in a Turpentine Orchard, as the district of forest to be worked is called, are occupied in making in the trunks of the trees, cavities which are technically known as boxes. For this purpose a long narrow axe is used, and some skill is required to wield it properly. The boxes are made from 6 to 12 inches above the ground, and are shaped like a distended waistcoat-pocket, the bottom being about 4 inches below the lower lip, and 8 or 10 below the upper. On a tree of medium size, a box should be made to hold a quart. The less the axe approaches the centre of the tree the better, as vitality is the less endangered. An expert workman will make a box in less than 10 minutes. From one to four boxes are made in each tree, a few inches of bark being left between them. The greater number of trees from which turpentine is now obtained, are from 12 to 18 inches in diameter, and have three boxes each.

The boxes having been made, the bark and a little of the wood immediately beneath it, which are above the box, are hacked; and from this excoriation, the sap begins to flow about the middle of March, gradually filling the box. Each tree requires to be freshly hacked every 8 or 10 days, a very slight wound above the last being all that is needed. The hacking is carried on year after year, until it reaches 12 to 15 feet or more, ladders being used. The turpentine, which is called dip, is removed from the boxes by a spoon or ladle of peculiar form, and collected into barrels, which are made on the spot and are of very rude construction. The first year’s flow of a new tree, having but a small surface to traverse before it reaches the box, is of special goodness and is termed Virgin dip.

The turpentine which concretes upon the trunk is occasionally scraped off and barrelled by itself, and is known in the market as scrape, or by English druggists as Common Frankincense or Gum thus.

Although a large amount of turpentine is shipped to the northern ports for distillation, a still larger is distilled in the neighbourhood of the turpentine orchards. Copper stills are used, capable of containing 5 to 20 barrels of turpentine. The turpentine is distilled without water, the volatile oil as it flows from the worm being received in the barrel in which it is afterwards sent to market. When all the oil that can be profitably drawn off has been obtained, a spigot is removed from an opening in the bottom of the still, and the residual Rosin, appearing as a viscid fluid-like molasses, is allowed to flow out. Only the first qualities of rosin, as that obtained from Virgin dip, are generally considered worth saving, the less pure sorts being simply allowed to run to waste. When it is intended to save the rosin, the latter is drawn off into a vat of water, which separates the chips and other rubbish, and the rosin is then placed in barrels for the market. A North Carolina turpentine orchard will remain productive under ordinary treatment for fifty years.

The collection of turpentine in the departments of the Landes and Gironde in the south-west of France, is performed in a more rational manner than in America, inasmuch as the plan of making deep cavities in the tree for the purpose of receiving the resin, is avoided by the simple expedient of placing a suitable vessel beneath the lowest incision.[2277] The turpentine which concretes upon the stem is termed in France Galipot or Barras.

Description—Common turpentine is chiefly of two varieties, namely, American and Bordeaux; the first alone is commonly found in the English market.

American Turpentine—A viscid honey-like fluid, of yellowish colour, somewhat opaque, but becoming transparent by exposure to the air; it has an agreeable odour and warm bitterish taste. When long kept in a bottle, it is seen to separate into two layers, the upper clear and faintly fluorescent, the lower somewhat turbid or granular. When the latter portion is examined under the microscope, it is found to consist mainly of minute crystals of peculiar curved or bluntly elliptic form. These crystals are abietic acid; when the turpentine is warmed, the crystals are speedily dissolved.

Bordeaux Turpentine—in all essential particulars agrees with American Turpentine; it appears to separate rather more readily than the latter into two layers,—a transparent and an opaque or crystalline.

Chemical Composition—The turpentines are mixtures of resin and essential oil. The latter, which amounts to from 15 to 30 per cent., consists for the greater part of various hydrocarbons, corresponding to the formula C₁₀H₁₆. Many of the crude turpentine oils, and some of them even after rectification, are energetically acted on by metallic sodium. This reaction proves the presence of a certain quantity of oxygenated oils, not one of which has thus far been isolated.

The turpentine oils, although agreeing in composition, exhibit a series of physical differences according to their origin. One and the same tree, indeed, yields from its several organs oils of different properties. The boiling point varies between 152° and 172° C. The sp. gr. at mean temperatures ranges from 0·856 to 0·870. Greater differences are exhibited in the optical properties, some varieties of the oil turning the plane of polarization to the right, others to the left. This rotatory power differs in many cases from that of the turpentine from which the oil was derived.[2278] The odour of oil of turpentine varies with the species from which it has been obtained.

When crude turpentine is distilled with water, nearly the whole of the oil passes over, while the resin remains. This resin is called Colophony or Rosin. When it still contains a little water, it is distinguished in English trade as Yellow Rosin; when fully deprived of water, it becomes what is called Transparent Rosin. That of deeper colour acquired by a still longer application of heat, bears the name of Black Rosin.

Colophony softens at 80° C., and melts completely at 100° into a clear liquid. At about 150° it forms a somewhat darker liquid, but without undergoing a loss in weight; at higher temperatures, it gradually decomposes. Pure colophony has a sp. gr. of 1·07, and is homogeneous, transparent, amorphous, and very brittle. At temperatures between 15° and 20° C., it requires for solution 8 parts of dilute alcohol (0·883). On addition of a caustic alkali, it dissolves in spirit much more freely. It is plentifully soluble in acetone or benzol.

The composition of colophony agrees with the formula C₄₄H₆₂O₄. By shaking coarsely powdered colophony with warm dilute alcohol, it is converted into a crystalline body, Abietic Acid, C₄₄H₆₄O₅,—a result due simply to hydration. Under such treatment, colophony yields 80 to 90 per cent. of abietic acid,[2279] and therefore consists chiefly of the anhydride of that acid. This is probably the case with the resins of other conifers. The living tree contains only the anhydride, for the fresh resinous juice is clear and amorphous after the expulsion of the oil; and when exposed to the air it loses oil, takes up water and solidifies as the crystalline acid,—a change which may easily be traced by the aid of the microscope, in drops taken direct from the trunk. Amorphous colophony retains its transparency even in a moist atmosphere, and appears to be capable of passing into the state of abietic acid, only when the assumption of the needful molecule of water is aided, in nature by the presence of the essential oil, or artificially by that of alcohol.

Colophony when boiled with alkaline solutions forms greasy salts of abietic acid, the so-ccalled resin-soaps, which are used as additions to other soaps.

Siewert’s Silvic Acid is regarded by Maly (1864) as a product of the decomposition of abietic acid; and the Pimaric, Pinic and Silvic Acids of former investigators, as impure abietic acid. Pimaric acid however, which is the chief constituent of Galipot, appears to be decidedly different, so far as we can judge from the experiments of Duvernoy (1865) and of one of ourselves (F.).

Abietic acid, as well as the unaltered coniferous resins, deviate the ray of polarized light, whereas American colophony, dissolved in acetone, is devoid of optical power.

Commerce—The supplies of turpentine are chiefly derived from the United States, but the trade has undergone a great change, as shown by the following figures, which represent the quantities imported in the several years:—

1869 1870 1871 1872

60,468 cwt. 51,257 cwt. 2,231 cwt. 1,000 cwt.

This greatly diminished importation of the crude article is partially explained by a larger importation of Oil of Turpentine and Rosin; but the increase is by no means sufficient to account for the vast diminution indicated by the above figures. The quantities of these latter articles imported into the United Kingdom during the year 1872 were as follows:—Oil of Turpentine, 220,292 cwt., value £470,085, six-sevenths being furnished by the United States of America and the remainder chiefly by France. Rosin, 919,494 cwt., value £492,246; of this quantity, the United States supplied nine-tenths, and France the larger part of the remainder.[2280]

Uses—Turpentine, Common Frankincense and Colophony are ingredients of certain plasters and ointments. Oil of turpentine is occasionally administered internally as a vermifuge or diuretic, and applied externally as a stimulant. But these substances are immeasurably less important in medicine than in the arts.

Thus Americanum vel vulgare.

This substance, known among druggists as Common Frankincense or Gum Thus, is the resin which, as explained at p. 605, concretes upon the stems of the pines in the American turpentine orchards, and is there called Scrape. It corresponds to the Galipot or Barras of the French, which in old times supplied its place.

It is a semi-opaque, softish resin, of a pale yellow colour, smelling of turpentine; it is generally mixed with pine leaves, bits of wood and other impurities, so that it requires straining before it is used. By keeping, it becomes dry and brittle, of deeper colour and milder odour. Under the microscope, it exhibits a crystalline structure due to Abietic Acid, of which it chiefly consists. It is imported from America in barrels, but in insignificant quantities and only for the druggist’s use. Sometimes, however, it is distilled as common turpentine.

Dry pine resin, of which Common Frankincense is the type, evolves when heated an agreeable smell; hence in ancient times it was commonly used in English churches in place of the more costly olibanum. At present it is scarcely employed except in a few plasters.

TEREBINTHINA VENETA.

Terebinthina Laricina; Venice Turpentine, Larch Turpentine; F. Térébenthine de Venise ou de Briançon, Térébenthine du mélèze; G. Venetianischer Terpenthin, Lärchen-Terpenthin.

Botanical Origin—Pinus Larix L. (Larix europæa DC.), a tall forest tree of the mountains of Southern Central Europe, from Dauphiny through the Alps to Styria and the Carpathians, ascending to an elevation of 3000 to 5500 feet above the sea-level. It is largely grown in plantations in England and also, since 1738, in Scotland.

History—The turpentine of the larch was known to Dioscorides as imported from the Alpine regions of Gaul.[2281] Pliny also was acquainted with it, for he correctly remarks that it does not harden. Galen in the 2nd century also mentions it, admitting that it may well be substituted for Chian turpentine (see p. 165), the true, legitimate Terebinthina. Yet even in the beginning of the 17th century many pharmacologists complained of such a substitution. Mattioli[2282] gave an account of the method of collecting it about Trent in the Tirol, by boring the trees to the centre, which is true to the present day. It used formerly to be exported from Venice, then the great emporium for drugs of all kinds; the turpentine may even at times have been collected in the territories of the Venetian republic. We find it expressly called Terebinthina Veneta by Guintherus of Andernach.[2283]

The name larch seems to belong to the turpentine rather than to the tree. Dioscorides says the resin is called by the natives λάρικα, and a similar name is mentioned by Galen. In Pasi’s Tariffa de pesi e misure, 1521 (see Appendix), we find “Termentina sive Larga,”—and larga is still an Italian name for larch turpentine. The peasants of the Southern Tirol call it Lerget, and in Switzerland the common name in German is Lörtsch.

Extraction—Larch turpentine is collected in the Tirol, chiefly about Mals, Meran, Botzen and Trent. A very small amount is obtained occasionally in the Valais in Switzerland, and in localities in Piedmont and France where the larch is found. The resin is obtained from the heartwood, by making in the spring a narrow cavity reaching to the centre of the stem at about a foot from the ground. This is then stopped up until the autumn of the same or of the following year, when it is opened and the resin taken out with an iron spoon. If only one hole is thus made, the tree yields about half a pound yearly without appreciable detriment. But if on the other hand a number of wide holes are made, and especially if they are left open, as was formerly the practice in the Piedmontese and French Alps, a larger product amounting to as much as 8 lb. is obtained annually, but the tree ceases to yield after some years, and its wood is much impaired in value.

Mohl, who witnessed the collection of this turpentine in the Southern Tirol,[2284] observed that when a growing larch stem was sawn through, the resin flowed most abundantly from the heartwood, and in smaller quantity, though somewhat more quickly, from the sapwood, and that the bark contained but few resin-ducts. The practice of closing the cavities is adopted, not only for the sake of preserving the wood and for the greater convenience of removing the turpentine, but also because it tends to maintain the transparency and purity of the latter.

Description—Venice turpentine is a thick, honey-like fluid, slightly turbid, yet not granular and crystalline; it has a pale yellowish colour and exhibits a slight fluorescence. Its odour resembles that of common turpentine, but is less powerful; its taste is bitter and aromatic. When exposed to the air, it thickens but slowly to a clear varnish, and hardens but very slowly when mixed with magnesia. Larch turpentine, though common on the Continent, is seldom imported into England,[2285] and the article sold for it is almost always spurious.

Chemical Composition—Larch turpentine dissolves in spirit of wine, forming a clear liquid which reddens litmus; hot water agitated with it also acquires a faint acid reaction, due to formic and probably also to succinic acid. Glacial acetic acid, amylic alcohol, and acetone mix with it perfectly. By distillation it yields on an average 15 per cent. of essential oil of the composition, C₁₀H₁₆, which boils at 157° C., and when saturated with dry hydrochloric acid gas, easily produces crystals of the compound C₁₀H₁₆ + HCl. The residual resin is soluble in two parts of warm alcohol of 75 per cent., and more copiously in concentrated alcohol.

Two parts of the turpentine diluted with one of benzol or acetone deviate the ray of polarized light 9·5° to the right. The essential oil deviates 6·4° to the left; the resin perfectly freed from volatile oil and dissolved in half its weight of acetone, deviates 12·6° to the right in a column 50 mm. long.

We have not succeeded in preparing a crystallized acid from the resin of Venice turpentine, although its composition according to Maly (1864) is the same as that of American colophony, which is easily transformed into crystallized abietic acid.

Uses—Venice turpentine appears to possess no medicinal properties that are not equally found in other substances of the same class, and as a medicine it has fallen into disuse. But in name at least it is in frequent requisition for horse and cattle medicines.

Adulteration—Alston (1740-60) said of Venice turpentine[2286] that it is seldom found in the shops,—a remark equally true at the present day, for but few druggists trouble themselves to procure it genuine. The Venice turpentine usually sold is an artificial mixture of common resin and oil of turpentine, which may be easily distinguished from the product of the larch by the facility with which it dries when spread on a piece of paper,[2287] and by its stronger turpentine smell.

CORTEX LARICIS.

Larch Bark.

Botanical Origin—Pinus Larix L.—see p. 609.

History—The bark of the larch has long been known to possess astringent properties; hence it has been used in tanning. Gerarde,[2288] who wrote near the close of the 16th century, likened it to that of the pine, which he described to be of a binding nature; but there is no evidence that it was an officinal drug.

About the year 1858 larch bark was recommended by Dr. Frizell of Dublin, and afterwards by other physicians, as a stimulating astringent and expectorant. In consequence of the favourable effects which have resulted from its use it has been included in the Additions to the Pharmacopœia of 1867.

Description—The bark that we have seen is in flattish pieces or large quills, externally reddish-brown. In those taken from older wood there is a large amount of an exfoliating corky coat, displaying as it is removed bright rosy tints, while the liber is of a different texture, slightly fibrous and whitish. The inner surface is smooth and of a pinkish-brown, or pale yellow. The bark breaks with a short fracture, exhaling an agreeable balsamic terebinthinous odour; it has a well-marked astringent taste. For medicinal use the inner bark is to be preferred.

Microscopic Structure—A transverse section exhibits resin-ducts, but far less numerous than in the bark of many allied trees. The medullary rays are not very distinct. Throughout the middle layer of the bark large isolated thick-walled cells of very irregular shape are scattered.

Chemical Composition—Larch bark has been examined by Stenhouse,[2289] who finds it to contain a considerable amount of a peculiar tannin, yielding olive-green precipitates with salts of iron. The same chemist also discovered[2290] in larch bark an interesting crystallizable substance called Larixin or Larixinic Acid, which has the composition C₁₀H₁₀O₅. It may be obtained by digesting the bark in water in 80° C. and evaporating the infusion to a syrupy consistence. From this, by still further cautious heating in a retort, the larixin may be distilled, during which operation some of it crystallizes on the inner surface of the receiver, the remainder being dissolved in the distilled liquor. From the latter it may be obtained in crystals by evaporation. The substance forms colourless crystals, sometimes as much as an inch long; it volatilizes even at 93° C., and melts at 153°. It requires about 88 parts of water for solution at 15° C., but more freely dissolves in boiling water or in alcohol. From ether, in which it is but sparingly soluble, it separates in brilliant crystals. The solutions have a bitterish astringent taste and a slightly acid reaction, and assume a purple hue on addition of ferric chloride. When a solution of baryta is added to a concentrated solution of larixin, the latter being in excess, a bulky gelatinous precipitate falls; it is readily soluble in boiling water and is deposited again on cooling. Stenhouse failed to obtain it either from the bark of Pinus Abies L., or from that of P. silvestris L.

Uses—Larch bark, chiefly in the form of tincture, has been prescribed to check profuse expectoration in cases of chronic bronchitis; it has also been found useful in arresting internal hæmorrhage.

TEREBINTHINA CANADENSIS.

Balsamum Canadense; Canada Balsam, Canadian Turpentine; F. Térébenthine ou Baume de Canada; G. Canada Balsam.

Botanical Origin—Pinus balsamea L. (Abies balsamea Marshall), the Balsam Fir or Balm of Gilead Fir, a handsome tree, 20 to 40 feet high, with a trunk 6 to 12 inches in diameter, sometimes attaining still larger dimensions, growing in profusion in the Northern and Western United States of America, Nova Scotia and Canada, but not observed beyond 62° N. lat. It resembles the Silver Fir of Europe (Pinus Picea L.), but has the bracts short-pointed and the cones more acute at each end.

Canada balsam is also furnished by Pinus Fraseri Pursh, the Small-fruited or Double Balsam Fir, a tree found on the mountains of Pennsylvania, Virginia, and southward on the highest of the Alleghanies.[2291]

Pinus canadensis L. (Abies canadensis Michx.), the Hemlock Spruce or Pérusse, a large tree abundant in the same countries as P. balsamea, and extending throughout British America to Alaska, is said to yield a similar turpentine, which however has not yet been sufficiently examined. The Hemlock Spruce is of considerable importance on account of the resin collected from its trunk, and the essential oil distilled from its foliage, the latter operation being performed on a large scale in Madison County, New York. The inner bark of the tree is a valuable material for tanning.

History—The French, in whose possession Canada remained until the year 1763, were probably acquainted with Canada balsam long before this period. Yet no mention of it is found in Pomet’s work, but in 1759 it was at Strassburg a current article of the pharmacy.[2292] As to England, Lewis, in his History of the Materia Medica published in 1761, says that “an elegant balsam,” obtained from the Canada Fir, is sometimes brought into Europe under the name of Balsamum Canadense. Canada balsam was first introduced into the London Pharmacopœia in 1788. From the books of a London druggist, J. Gurney Bevan, we find that its wholesale price in 1776 was 4s., in 1788, 5s. per lb.

Description—Canada balsam is a transparent resin of honey-like consistence, and of a light straw-colour with a greenish tint. By keeping, it slowly becomes thicker and of a somewhat darker hue, but always retains its transparency. When carefully examined in direct sunlight, it exhibits a slight greenish fluorescence in the same degree as other turpentines or as copaiba; this optical power appears to increase if the balsam is exposed to a heat of about 200° C.

Canada balsam has a pleasant aromatic odour and bitterish, feebly acrid, not disagreeable taste. On account of its flavour it is sometimes called Balm of Gilead, but erroneously, as this latter is derived from a tree of the genus Balsamodendron growing in Arabia. We found a good commercial balsam to have a sp. gr. of 0·998 at 14·5° C., water at the same temperature being 1·000. Four parts, mixed with one of benzol and examined in a column of 50 mm. in length, deviated a ray of polarized light 2° to the right. The balsam is perfectly soluble in any proportion in chloroform, benzol, ether, or warm amylic alcohol; and the solution in each case reddens litmus. With sulphate of carbon it mixes readily, but the mixture is somewhat turbid. Glacial acetic acid, acetone or absolute alcohol dissolve the balsam partially, leaving, after ebullition and cooling, a considerable amount of amorphous residue. Colophony and Venice turpentine are completely dissolved by the liquids in question, as well as by spirit of wine containing 70 to 75 per cent. of alcohol.

Chemical Composition—Like all analogous exudations of the Coniferæ, Canada turpentine is a mixture of resins with an essential oil. If the latter is allowed to evaporate, the former are left as a transparent, somewhat tough and elastic mass. The proportion of the components is within certain limits, variable in different samples. The specimen before mentioned lost after an exposure in a steam-bath during several days, no less than 20 per cent. of volatile oil, or even 24 per cent. if the experiment was made on a very small scale, as with 20 grammes or less in a thin layer.

By distillation with water, it is not easy to obtain more than 17 to 18 per cent. of essential oil. The resin in this case is a tough, elastic, non-transparent mass, retaining obstinately a large proportion of water, which can only be removed by keeping it for some time at a temperature of 100°-176° C.

The oil as obtained by distillation with water is colourless, and has the odour of common oil of turpentine rather than the agreeable smell of the balsam; it consists of an oil, C₁₀H₁₆, mixed with an insignificant proportion of an oxygenated oil, the presence of which may be proved by the slight evolution of hydrogen on addition of metallic sodium, after the oil has been freed from water by contact with fused chloride of calcium. After this treatment, a small proportion begins to distil at about 160°, but by far the larger part boils at 167° C., a small portion only distilling at last at 170° and above. The oil obtained at 167°, examined under the conditions already mentioned, has a sp. gr. of 0·863, and the power of rotating a ray of polarized light 5·6° to the left. The portion distilling at 160° does not differ in this respect; but that passing over at 170°, deviates the ray 7·2° to the left. The oil readily dissolves a large proportion of glacial acetic acid; an equal weight of each mixes perfectly at about 54° C., but some acetic acid separates on cooling.

The essential oil of Canada balsam, saturated with dry hydrochloric acid, does not yield a solid crystallizable compound; but this is easily obtained on addition of fuming nitric acid and gently heating, when the inside of the retort becomes covered by sublimed crystals of C₁₀H₁₆ + HCl.

Thus this oil in its general characters bears a close resemblance to the essential oils of the cones of Pinus Picea L., and of the leaves of P. Pumilio Hänke, and to most of the French varieties of oil of turpentine, rather than to the American turpentine oils, which rotate to the right, and combine immediately with HCl to form a solid crystalline compound.

On the other hand, the resin of Canada balsam is dextrogyre: two parts of it, entirely deprived of essential oil and dissolved in one of benzol, deviating the ray 8·5° to the right. The optical powers of the two components (oil and resin) are therefore antagonistic.

The resin of Canada balsam consists however of two different bodies, 78·7 per cent. of it being soluble in boiling absolute alcohol, and 21·3 (in our specimen) remaining as an amorphous mass, readily soluble in ether. Neither the alcoholic nor the ethereal solution yields a crystalline residue if allowed to evaporate. They redden litmus, but we did not succeed in obtaining any crystallized resinous acid, crystals of which are formed if common turpentine or colophony is digested with dilute alcohol. Glacial acetic acid acts upon the resins like absolute alcohol. Caustic alkalis do not dissolve either the balsam or the resin; the former however is considerably thickened by incorporation with ⅕ of its weight of recently calcined magnesia. If the mixture, moistened with dilute alcohol, is kept at 93° C. for some days and frequently stirred, a mass of hard consistence, finally translucent, results. Caustic ammonia heated with the balsam in a closed bottle, forms a thick milky jelly, which does not afterwards separate.

Hence, according to our investigations, 100 parts of Canada turpentine consist of

Essential oil, C₁₀H₁₆}, with a very small

proportion of an oxygenated oil 24

Resin soluble in boiling alcohol 60

Resin soluble only in ether 16

The result of Wirzen’s examination of Canada balsam[2293] are not in complete accordance with those here stated. He found 16 per cent. of oil and three different amorphous resins, one of which had the composition of abietic acid.

Production and Commerce—Canada balsam is obtained either by puncturing the vesicles which form under the suberous envelope of the trunk and branches, and collecting their fluid contents in a bottle, or by making incisions. It is obtained principally in Lower Canada, and is shipped from Montreal and Quebec, in kegs or large barrels. In the neighbourhood of Quebec, about 2000 gallons (20,000 lb.) used to be collected annually; but in 1868, owing to distress among the farmers, the quantity obtained was unusually large, and it was estimated that nearly 7000 gallons would be exported to England and the United States.[2294] During a recent scarcity (1872-73) a sort of balsam from Oregon has been substituted in the American market for true Canada balsam.[2295]

Uses—The medicinal properties of Canada balsam resemble those of copaiba and other terebinthinous oleo-resins, yet it is now rarely employed as a remedy. The balsam is much valued for mounting objects for the microscope, as it remains constantly transparent and uncrystalline. It is also used for making varnish.

TEREBINTHINA ARGENTORATENSIS.

Strassburg Turpentine; F. Térébenthine d’Alsace ou de Strasbourg, Térébenthine du sapin; G. Strassburger Terpenthin.

Botanical Origin—Pinus Picea L. (Abies pectinata DC.), the Silver Fir,[2296] a large handsome tree, growing in the mountainous parts of Middle and Southern Europe from the Pyrenees to the Caucasus, and extending under a slightly different form (var. β. cephalonica) into continental Greece and the islands of Eubœa and Cephalonia.

History—Belon in his treatise De Arboribus coniferis (1553) described this turpentine, which is also briefly yet accurately noticed by Samuel Dale,[2297] a learned apothecary of London and the friend of Sloane and Ray. It had a place in the London Pharmacopœia until 1788, when it was omitted from the materia medica.

Extraction—The oleo-resin of P. Picea, like that of P. balsamea, is contained in little swellings of the bark[2298] of young stems, and is extracted by the tedious process of puncturing them and receiving in a suitable vessel the one or two drops which exude from each. It is still collected near Mutzig and Barr, in the Vosges (1878), though only to a very small extent.

Description—An authentic sample collected for one of us by the Surveyor of Forests in the Bernese Jura, Switzerland, resembles very closely Canada balsam, but is devoid of any distinct fluorescence. It has a light yellow colour, a very fragrant odour,[2299] more agreeable than that of Canada balsam, and is devoid of the acrid bitterish taste of the latter.

We found our specimen to have sp. gr. of distilled water. It deviates a ray of polarized light 3° to the left, if examined either pure or diluted with a fourth of its weight of benzol, in the manner described at p. 610. Our drug is soluble in the same liquids as the Canadian, yet is miscible with glacial acetic acid, absolute alcohol and acetone, without leaving any considerable flocculent residue. It is even soluble in spirit of wine, the solution being but very little turbid. The solutions have an acid reaction.

Chemical Composition—After the complete desiccation of a small quantity, there remained 72·4 per cent. of a brittle, transparent resin, soluble in glacial acetic acid, but not entirely in absolute alcohol or in acetone. By submitting half a pound of the turpentine to distillation with water, we obtained 24 per cent. of essential oil, the remaining resin being when cold perfectly friable. The fresh oil, purified by sodium, deviates the ray of polarized light to the left, whereas the remaining resin, dissolved in half its weight of benzol, shows a weak dextrogyre rotation. The oil boils at 163° C. After having kept it for two years and a half in a well-stopped bottle, we find that it has become considerably thicker and now deviates to the right. If saturated with dry hydrochloric acid, the oil does not yield a solid compound.

This oil has nearly the same agreeable odour as the crude oleo-resin, yet the essential oil of the cones of the same tree is still more fragrant. The latter is one of the most powerfully deviating oils, the rotation being 51° to the left, and it is consequently extremely different from the oil obtained from the turpentine of the stem, though its composition is represented by the same formula, C₁₀H₁₆.

A peculiar sugar called Abietite, nearly related to mannite but having the composition C₁₂H₁₆O₆, has been detected by Rochleder[2300] in the leaves of the Silver Fir.

Uses—Strassburg turpentine possesses the properties of common turpentine, with the advantage of a very agreeable odour. It was formerly held in great esteem, but has now become nearly forgotten.

PIX BURGUNDICA.

Pix abietina; Burgundy Pitch; F. Poix de Bourgogne ou des Vosges, Poix jaune; G. Fichtenharz, Tannenharz.

Botanical Origin—Pinus Abies L. (Abies excelsa DC.), the Norway Spruce Fir,[2301] a noble tree attaining an elevation of 100-160 feet, widely distributed throughout Northern and the mountainous parts of Central Europe, but not indigenous to Great Britain, though extensively planted. In Russian Lapland it reaches at 68° N. lat. almost the extreme limit of tree-vegetation, while southward it extends to the Spanish Pyrenees. In the Alps it ascends to 6,000 feet above the level of the sea.

History—In accordance with the definition of the London Pharmacopœias and the custom of English druggists the name Burgundy Pitch is restricted to the product of the above-named species. The pharmacologists of France use an equivalent term with the same limitations; but in other parts of the Continent Pix Burgundica has a wider meaning, and is allowed to include the turpentines of other Coniferæ. We here employ it in the English sense.

Parkinson, an apothecary of London and herbarist to King Charles I., speaks of “Burgony Pitch” as a thing well known in his time.[2302] Dale in his Pharmacologia (1693) mentions Pix Burgundica as being imported into England from Germany, and it is also noticed by Salmon (1693), who says “it is brought to us out of Burgundy, Germany and other places near Strasburgh.”[2303]

Pomet, writing in Paris about the same period, discards the prefix Burgundy as a fiction, remarking that the best Poix grasse comes from Holland and Strassburg.[2304]

Whether this resin ever was collected in Burgundy we are unable to determine. It may probably have acquired the name through having been brought into commerce from Switzerland and Alsace by way of Franche Comté, otherwise called Comté de Bourgogne or Haute Bourgogne.[2305]

Burgundy pitch is enumerated among the materia medica of the London Pharmacopœia of 1677, and in every subsequent edition. In that of 1809 it was defined under the name of Pix arida, as the prepared resin of Pinus Abies.

Production—Burgundy pitch is produced in Finland, in the Black Forest in the Grand Duchy of Baden, Austria and Switzerland. On the estate of Baron Linder at Svarta near Helsingfors, it is obtained by melting the crude resin in contact with the vapour of water, and straining. The quantity annually produced there was stated in 1867 to be 35,000 kilogr. (689 cwt.);[2306] that afforded by an establishment at Ilm in the same country amounted to 80,000 kilogr. (1,575 cwt.).[2307]

In the neighbourhood of Oppenau and on the Kniebis mountain in the Grand Duchy of Baden the stems of the firs are wounded at equal distances by making perpendicular channels, 1½ inches wide and the same in depth. The resin which exudes from these channels is scraped off with an iron instrument made for the purpose, and purified by being melted in hot water and strained. This is performed in three or four small establishments at Oppenau and the neighbouring village of Löcherberg. In this state the resin, which is opaque and contains much moisture, is called Wasserharz. By further straining and evaporating a portion of the water its quality is improved.

The manufacture in that part of Germany is on the decline, partly in consequence of the timber being injured by the wounding of the trees, so that the collecting of resin is not permitted in the large forests belonging to the governments of Baden and Württemberg. We have had the opportunity of observing[2308] that in the establishments in question French turpentine or galipot, imported from Bordeaux, as well as American rosin or colophony, are used in quantities certainly exceeding that of the resin grown on the spot.

In the middle of the last century some Burgundy pitch was produced, according to Duhamel,[2309] in the present canton of Neuchâtel, but no such branch of industry is now pursued there, at least on a large scale. On the other hand, in the districts of Moutier and Delémont in the Bernese Jura this resin is still collected, though it is not known as Burgundy Pitch, but is termed simply Poix blanche (White Pitch). The surveyor of the forests of this district, which is one of the richest in Pinus Abies, has informed one of us that from 790 to 850 quintals are collected and exported to Basle, Zürich, Aarau and Vaud. The pitch is worth in loco (1868) 100 to 110 francs (£4 to £4 8s.) the bosse of 6 quintals. The quantities collected in other parts of Switzerland are even less considerable.

Description—Pure Burgundy pitch, of which we have numerous authentic specimens, is a rather opaque, yellowish-brown substance, hard and brittle when cold, yet gradually taking the form of the vessel in which it is kept. It is strongly adhesive, breaks with a clear conchoidal fracture, and has a very agreeable, aromatic odour, especially when heated. It does not exhibit a crystalline structure, although, as we have frequently observed, the resin on the stem of the tree is distinctly crystalline.

Burgundy pitch is readily soluble in glacial acetic acid, acetone, absolute alcohol, and even in alcohol of 75 per cent. (sp. gr. 0·860), yet its solubility in these liquids is considerably altered by the presence of water or essential oil; and still more by the formation of abietic acid in the resin itself. The same influences also affect the melting point.

The crude resin of Pinus Abies,[2310] deprived of essential oil and dissolved in one part of absolute alcohol, was found to deviate a ray of polarized light 3° to the left, in a column of 50 mm.; the essential oil deviated 8·5° to the same direction. The oil contains a small amount of an oxygenated oil. After treatment with sodium the oil which remains does not form a solid compound if saturated with hydrochloric acid.

Chemical Composition—The investigations of Maly mentioned at p. 607 afford a satisfactory elucidation of the chemical properties of the pinic resinous exudations. They all, according to that chemist, are mixtures of the same amorphous resin, C₄₄H₆₂O₄, with essential oils of the composition C₁₀H₁₆. These terebinthinous juices are collected and sold either in their natural state as turpentine, or deprived more or less completely of their volatile oil, in which condition they are represented by Burgundy Pitch, and finally by rosin or colophony.

The turpentines flowing down the stems of the trees gradually lose their transparency if allowed to dry slowly in the air, becoming at the same time harder and somewhat granular. This alteration is due to the incorporation of water, which at last is not only mixed with the components of the resinous juice, but to some extent combines chemically with the resin so as to transform it into a crystalline body having the characters of an acid. The fact is easily observed if clear drops of the turpentine of Pinus silvestris, P. Abies or P. Picea are collected in vials and kept perfectly dry. Thus treated these turpentines remain transparent, but the addition of water causes after a short time the formation of microscopic crystals of abietic acid, rendering them more or less opaque.

If turpentines are collected before they lose their essential oil by evaporation and oxidation, and before they have become crystalline, they can be retained perfectly transparent by distilling off the volatile oil without water. The distillation being most commonly carried on with water, the remaining resin is opaque.

Maly is of opinion that the same amorphous resin occurs in all the Coniferæ, and that it yields by hydration the same acid, namely Abietic, which has been described by former chemists as Pinic, Silvic, and Pimaric acids, all of which indeed are admitted to have the same composition. We must however remember that several sorts of turpentine, as Canada Balsam, appear incapable, according to our experiments, of yielding any crystalline resinoid compound whatever; and that their amorphous resin being but partially soluble is certainly not a homogeneous substance.

The crystals as formed naturally in the common turpentines do not exhibit precisely the same forms as those obtained artificially when the resins are agitated with warm diluted alcohol, as in the preparation of abietic acid. As to Pimaric Acid, we have prepared it in quantity from galipot, the resin of Pinus Pinaster, but have always found its crystalline character entirely different from that of abietic acid.[2311]

We are inclined, therefore, to think that the composition of the resins of Coniferæ is not so uniform as Maly suggests. The remarkable variety of their essential oils is a fact which seems in favour of our view.

Uses—Burgundy pitch is prescribed as an ingredient of plasters, and thus employed is useful as a mild stimulant. In Germany it has some economic applications, one of which is the lining of beer casks, for which purpose a composition is used called Brauerpech (brewers’ pitch), made by mixing it with colophony or galipot.

Adulteration—No drug is the subject of more adulteration than Burgundy pitch, so much so that the very name is understood by some pharmacologists to be that of a manufactured compound. The substance commonly sold in England is made by melting together colophony with palm oil or some other fat, water being stirred in to render the mixture opaque. In appearance it is very variable, different samples presenting different shades of bright or dull yellow or yellowish-brown. Many when broken exhibit numerous cavities containing air or water; all are more or less opaque, becoming in time transparent on the surface by the loss of water. Artificial Burgundy pitch is offered for sale in bladders; it has a weak terebinthinous odour, and is devoid of the peculiar fragrance of the genuine. The presence of a fatty oil is easily discovered by treatment with double its weight of glacial acetic acid, which forms a turbid mixture, separating by repose into two layers, the upper being oily.