The subject of the colorific and coloring principles of the lichen has, within the last few years, attracted a due share of that attention which, has been increasingly devoted to organic chemistry. Since 1830, Heeren, Kane, Schunck, Rochleder and Heldt, Knop, Stenhouse, Laurent and Gerhardt, have published valuable papers on these principles; but, here again, we have to regret the great discrepancy in the various results obtained, and there is therefore, here also, imperatively demanded re-investigation and correction before any of the results already published can he implicitly relied upon, and before we can have safe data from which to generalise. I have no doubt that a great proportion of the obscurity overhanging this subject depends on the circumstance that many of the chemists, who have devoted attention to the color-educts and products of the lichens, were not themselves botanists, and have therefore probably, in some cases at least, analysed species under erroneous names, and also because their investigations have comprehended a much too limited number of species.
Their utility in the arts, and especially in dyeing—including the collection of a series of the commercial dye lichens, i.e., those used by the manufacturers of London, &c., in the making of orchil, cudbear, litmus, and other lichen dyes. While investigating the dyeing properties of the lichens, I made experiments, with a view to test their colorific power, on as many species as I could obtain in sufficient quantity, to render it at all useful to operate on—that number, however, being very limited (between forty and fifty).
Dr. Lindley adds, many parties may be able to aid his investigations, by furnishing information on their economic uses, and on their special applications in dyeing and other arts—(particularly on their employment, as dye agents, by the natives of Britain and other countries)—with specimens of the lichens so used, and their common names—specimens of fabrics dyed therewith—notes of the processes employed for the elimination of the dyes, &c. Parties resident in, or travelling through our western Highlands and Islands, the northern Highlands, Ireland, Wales, Norway, Iceland, and similar countries, are most likely to be able to afford this description of information—many native lichens being still used by the peasantry of these countries to dye their homespun yarn, &c.
He proceeded to treat—1. The vast importance of this humble tribe of plants in the grand economy of nature, as the pioneers and founders of all vegetation. 2. Their importance to man and the lower animals, as furnishing various articles of food. 3. Their importance in medicine, and especially in its past history, at home and abroad. 4. Their importance in the useful and fine arts, and especially in the art of dyeing. 5. Their affinities and analogies to other cryptogamic families, and to the Phanerogamia. 6. Their value as an element of the picturesque in nature; and, 7. Their typical significance.
He then adverted more especially to the subject of his communication, under the ten following heads:—
I. The colors of the Thallus and apothecia of Lichens—their causes, and
the circumstances which modify and alter them.
II. History of the application of their coloring matters to the art of dyeing.
III. Chemical nature and general properties of these coloring matters.
IV. Tests and processes for estimating qualitatively, and quantitatively the
colorific powers of individual species—with their practical applications.
V. Processes of manufacture of the Lichen-dyes, on the large and small
scale in different countries—with the principles on which they are founded.
VI. Nomenclature of the dye-Lichens, and of the Lichen-dyes.
VII. Botanical and commercial sources of the same.
VIII. Special applications of the Lichen-dyes in the arts.
IX. Commercial value of the dye-Lichens, and their products.
X. Geographical distribution of the dye-Lichens—with the effect of climate;
situation, &c., on their colorific materials.
Of the four first sections of his paper, the following is a very short summary or synopsis:—
Under the first head, the author spoke of chlorophylle and various organic and inorganic substances, which enter into the formation of the colors of the thallus and apothecia of lichens, and of the modifications of these colors depending on various degrees of—1. Exposure to air and light. 2. Temperature. 3. Moisture, &c. 4. Atmospheric vicissitudes. 5. Season of the year. 6. Nature of the Gonidic reproduction (i.e., gemmation). 7. Nature of habitat. 8. Organic decomposition. 9. Coalescence of parts, monstrosities, &c.
Under the second section, he traced historically the manufacture of Lichen-dyes, and the native use of Lichens as dye agents, among different nations, from the times of Theophrastus, Dioscorides, and Pliny, down to the present day, sketching briefly the ancient end modern history of orchil, cudbear, and litmus, and specifying the native use of lichen-dyes in different, countries of Europe, Asia, and America. He alluded more particularly to their application to the dyeing of yarns, &c., by the Scotch Highlanders, under the name of "Crottles." "The process of the manufacture of the various crottles, generally consisted in macerating the powdered lichen for two or three weeks, in stale urine, exposing the mass freely to the air by repeated stirring, and adding lime, salt, alum, or argillaceous and other substances, either to heighten the color or impart consistence. To such an extent did this custom at one time prevail, that, in several of our northern counties each farm and cottage had its tank or barrel of putrefying urine, a homely but perfectly efficient mode of generating the necessary amount of ammonia. In the county of Aberdeen, in particular, every homestead had its reservoir of "Graith,"[53] and the "Lit-pig,"[54] which stood by every fireside, was as familiar an article of furniture in the cots of the peasantry, as the "cuttie-stool," or the "meal girnel." So lately as 1841 (and I presume the practice continues to the present day), Mr. Edmonston stated that, of four or five native dyes, used by the Shetlanders to color cloth and yarns, two at least were furnished by lichens, viz., a brown dye from Parmelia saxatilis, under the name of "Scrottyie," and a red one from Lecanora tartarea, under that of "Korkalett." It is very probable, however, that steam and free trade have gradually dispelled this good old custom, even in the remoter corners of our island; machinery-made articles being now readily supplied, at a rate so extraordinarily cheap, as to render it absolutely expensive (as to time, if not also as to money) to prepare colors, even by a process so simple and inexpensive as that just mentioned."
Under the third head, he examined, in a general way, the chemistry of the colorific and coloring matters of the lichens and the results to which it has led, avoiding as much as possible the technicalities inseparable from such a subject, and giving a short vise of the researches of Heeren, Kane, Rochleder, and Heldt, Stenhouse, Schunck, Laurent, and Gerhardt, and others. "Our untaught senses should undoubtedly lead us to expect the lichens, whose thallus exhibits the brightest tints, to yield the finest dyes, and these, too, of a color similar to that of the thallus, but experience teaches us that the beautiful reddish or purplish coloring-matters are producible in the greatest abundance by the very species from which we should least expect to derive any, viz., in those most devoid of external color. This, though at first sight very remarkable, is easily explicable, when we remember that, in most of the so-called dye-lichens, colorific principles exist in a colorless form, and only become converted into colored substances under a peculiar combination of circumstances.
"Some lichens contain coloring matters, ready formed, and these exhibit themselves in the tint of the thallus of the plants, e.g. chrysophanic [or parietinic] acid in Parmelia parietina, and vulpinic acid in Evernia vulpina. In other species we find principles, which, while in the plant, and unacted on by chemical re-agents, are colorless, but which, when the lichens are exposed to the combined influence of atmospheric air, water, and ammonia, yield colored substances. This series of colored products is usually comprehended more for convenience sake than on account of chemical identity, under the generic term orceine."
The whole subject of the chemistry of these bodies is at present in a most unsatisfactory condition, demanding fresh investigation and research, in illustration of which, the author exhibited tables of the colorific and coloring principles, so far as they are at present known, showing their chemical formulæ and the authority therefor, and various relative information. "It is highly probable that when the chemistry of the lichens has been more fully studied, and the whole subject of their color-educts and products better understood, we shall begin to reduce the present confused mass of complex substances, and find the same principles more extensively diffused through different lichen species." Dr. L. entered somewhat minutely on the chemical reactions of the better known colorific and coloring principles, and their derivatives, so far at least as these throw any light on the production and transmutation of the red or purple colors extracted from what may be termed par excellence, the dye-lichens. After a few remarks on the chemical constitution of orchil and litmus, as given by Kane, Gelis, Pereira, and others, he discussed the subject of decolorisation of weak infusions of orchil and litmus by exclusion of atmospheric air, and by various deoxidising agents, and the different theories as to the causation of this phenomenon. "I have repeatedly had occasion to notice that, when weak infusions of these substances are excluded for some time from atmospheric air, in a bottle, with a tightly fitting cork, they gradually lose color, but rapidly regain it on re-exposure. It is curious that both orchil and litmus are what are called transient or false colors, i.e., they slowly lose their bloom and tint by long exposure to the atmosphere; the coloring matter, therefore, appears to be decolorised both by exposure to, and exclusion from the air, phenomena apparently of very opposite characters. The cause of the latter phenomenon has never, so far as I am aware, been quite satisfactorily explained; but it has been variously supposed to be due:—
1. To the mere negation of oxygen.
2. To the development, in the liquids, of various substances, capable of exerting a decolorising influence on the coloring matter.
3. To deoxidation of the coloring matter by substances, which have a great tendency to become oxidised or peroxised; e.g. hydrogen, in the case of decolorisation by sulphuretted hydrogen, nascent hydrogen, and the protoxides of iron and tin, &c.
4. To the fixation of an additional amount of hydrogen in a new colorless body, formed by the union of the sulphuretted hydrogen or other substances with the coloring matter of the liquid. This view is chiefly supported by Kane, who says, "that precisely as the coloring matters combine with water, to form different shades of red-colored bodies—with ammonia to produce a series of bodies, which are blue and purple—so they combined with sulphuretted hydrogen to form colorless compounds in solution, which, if solid, very probably would be white." He supposes, in a word, that for every colored substance existing in orchil and litmus, there is a corresponding white one, producible by the action of sulphuretted hydrogen, &c.; and, in proof of this theory, he mentions having obtained from Azolitmine and Betaorceine colorless bodies, to which he gave the respective names of Leuco-litmine and Leuco-orceine.
The author then gave a short summary of Dr. Westring's experiments on the dyeing powers of the Swedish lichens, which he found might be conveniently divided into four classes, according to the degree of heat employed in their maceration, viz.:—
1. Lichens, whose coloring matter was easily extractable by cold water alone.
2. Those which required for the elimination of their coloring matter, maceration in tepid water (i.e. below 258 degs. Swedish thermometer).
3. Those which required maceration in warm water (i.e.between 50 and 60 degs. Swedish thermometer).
4. Those requiring boiling water alone, or with the aid of solvents.
"It must be admitted that our knowledge of the true nature of the colorofic and coloring principles of the lichens is, as yet, very imperfect and confused, and one great cause of the dubity and obscurity overhanging the subject, is the fact that different analysts have arrived at most opposite results, even in the examination of the same species. For instance, in Rocella tinctoria, which has, of all the dye-Lichens, been most frequently selected for analytical investigation, on account of its important product orchil, the discrepancies between the results obtained are very striking. In it Heeren discovered his Erythrine; Kane his Erythriline; Schunk his Erythric acid; and Stenhouse three different substances in as many varieties of the plant; all of these bodies differing more or less from each other in composition and properties (at least, if we are to assume, as correct, the descriptions given of them by their respective discoverers").
"I have already hinted that there is no ratio between the external and internal color or structure of a lichen, and the kind or amount of coloring matter it will be found to yield. It is exceedingly natural to suppose that such a ratio should exist; but, proceeding for some time on this supposition, I was frequently disappointed in my results—the most showy and brilliantly colored lichens often furnishing the dullest and most worthless colors. For instance, the bright yellow thallus of Parmelia parietina, and the beautiful scarlet apothecia of Scyphophorus cocciferus, instead of producing a rich yellow in the one case, and a deep crimson in the other, yielded, respectively, only dirty greenish-yellow and brownish colors. As a general rule I should almost be inclined to say that the finer the color of the thallus of any given lichen, the more is that lichen to be suspected of poverty in valuable coloring matters; and that, on the other hand, the palest pulverulent or crustaceous species, especially such as are saxicolous, may be expected to yield the most beautiful and valuable pigments (e.g. the Rocellas and Lecanoras). In such circumstances it is necessary to have some test, of easy applicability, of the kind and amount of colorific properties of any lichen, and this fortunately is readily attainable."
The fourth section of the paper was devoted to the consideration of the various tests of colorific power, which have been recommended by different authors. "Of these, the greater number proceed on the principle of developing the coloring matter by some alkali, in conjunction with the decomposing action of atmospheric oxygen and water; others are founded on the reaction between colorific principles of certain of the dye lichens and some of our ordinary chemical re-agents." The author noticed in particular—
| 1. Helot's test, | } }qualitative. } |
| 2. Westring's tests, | |
| 3. Stenhouse's test, | |
| 4. Stenhouse's test, | quantitative. |
Helot's test consists in digesting the dried and powdered lichen or a few hours, at a temperature of 130 degs., in a weak solution of ammonia, sufficiently strong, however, to be tolerably pungent. One that is fit for the dyer will yield a rich violet red liquor.
Dr. Westring recommended simply macerating three or four drachms of the lichen in cool spring water, assisting, perhaps, the solvent action of the water by minute quantities of common salt, nitre, quicklime, sulphate of copper or iron, or similar re-agents. If these means failed, after a sufficient length of time had been allowed for the development of color, he digested a fresh portion of the pulverised lichen in water, containing small quantities of sal-ammoniac and quicklime [in the proportion of 25 parts of water, 1-10th lime, and 1-20th sal-ammoniac for every part of lichen], for a period varying from eight to fourteen days, and by this process, he says, he never failed to develop all the color which the plant was capable of yielding.
Dr. Stenhouse, of London, one of our latest and best authorities on the chemistry of the lichens, adds to an alcoholic infusion of the lichen, a solution of common bleaching powder (chloride of lime), whereby, if it contain certain colorific principles capable of developing, under the joint action of air, water, and ammonia, red coloring matters, a fugitive but distinct blood-red color will be exhibited. The amount of this colorific matter may be estimated quantitatively by noting the quantity of the chloride of lime solution required to destroy this blood-red color in different cases: or the same result may be obtained by macerating for a short period in milk of lime—filtering—precipitating the filtered liquor by acetic or muriatic acid—collecting this precipitate on a weighed filter—drying at ordinary temperatures and again weighing.
The author entered into a full analysis of these tests and processes—pointing out their respective advantages and disadvantages—and showing their practical value and applications. He stated that he had made use of these, and various other tests, in upwards of 300 experiments, and the one which he employed to the greatest extent, because most uniformly applicable, was Helot's ammonia test. The following combination is that most favorable for the development of the coloring matter of the lichens—viz., the presence
| 1. | Of water as a solvent menstruum. |
| 2. | Of atmospheric oxygen. |
| 3. | Of ammonia, in the state of vapor or in solution, and |
| 4. | Of a moderate degree of heat; |
And according as the proportion of these combining elements varies, so do the kind and amount of color educed by them. This combination is the foundation of all the processes for the manufacture of the lichen dyes throughout the world, however different these may appear to be in detail or results.
I believe it may come to be a matter of great commercial importance to discover, at home or abroad, some cheap and easily-procurable substitute for the Roccellas, which are gradually becoming scarce, and consequently valuable in European commerce, having sometimes fetched, in times of scarcity, no less than £1,000 per ton. No plants can be so easily collected and preserved as lichens—requiring merely to be cleaned, dried, pulverised, and packed; and if their bulk be an objection to transport, their whole colorific matter may be collected in the way I have already mentioned. Ascending to the verge of eternal snows, and descending to the ocean level—with a geographical diffusion that is co-extensive with the surface of our earth, it is difficult to say where lichens shall not be found. There are myriads of small rocky islets in the boundless ocean, and there are thousands of miles of barren rocky coast and sterile mountain range in every part of the world, which, though at present unfit to bear any of the higher members of the vegetable kingdom, are yet carpeted and adorned with a rich covering of lichens, and of those very species too, which I have already spoken of as prolific in colorific materials. I sincerely believe, therefore, that a more general attention to the very simple tests just enumerated, would ultimately result in a greatly extended use of the lichens as dye agents. What renders it very probable that efforts in this direction are likely to meet with success is the great similarity of species found all over the world. It has been repeatedly noticed that the European species, which, of course, are best known, differ little from those of North America. Dr. Robert Brown remarked the same fact with regard to New Holland species, and Humboldt also recognised the similarity in natives of the South American Andes. Of a large collection made by Professor Royle, in the Himalayas, Don pronounced almost every one to be identical with European species. From examining the raw vegetable products, sent by different countries to the Great Exhibition of 1851, I am satisfied that, even now, there are many fields open for the establishment of an export trade in Roccellas and other so-called orchella weeds." I there saw specimens of good dye lichens from almost every part of the world, including our own young colonies; and as a single instance of their probable value, I may introduce here the copy of a note appended to a specimen of orchella weed from the island of Socotra, contained in the Indian collection of that exhibition, "abundant, but unknown as an article of use or commerce. Also abundant on the hills around (Aden) and might be made an article of trade." Roccellas from this source are estimated as worth £190 to £380 per ton. I believe that a similar statement might be made with regard to the countless islands of the broad Atlantic and Pacific, which may, at some future period, perhaps not far distant, be found to be rich depots of orchella weeds, just as some of them are, at present, rich fields of guano, and may, as such, become new nuclei of British commerce and enterprise. Even at home, in the immediate vicinity of Edinburgh, or, to restrict our limits still more narrowly, within the compass of Arthur's Seat, there are not a few very good dye-lichens, which require merely to be scraped with an old knife or similar instrument, from the rocks to which they adhere, and subjected to the ammonia process already mentioned. Of twelve specimens thus collected at random one morning, I found no less than three yielded beautiful purple-red colors, apparently as fine as orchil or cudbear, while the others furnished rich and dark tints of brownish-red, brown and olive-green.
Dr. Lindley's communication was illustrated with specimens of coloring matters yielded by various lichens collected in the neighbourhood of Edinburgh, &c.
BARKS FOR TANNING.
Let us now take a brief review of the sources from whence tanning materials may be obtained, which will also enable us to form a fair estimate of the prospect of future supplies. Only one medal was awarded, at the Great Exhibition, for tanning substances, viz., to Messrs. Curtis, Brothers (United Kingdom, No. 126), but honorable mention was made of the following competitors:—One from Tunis, one from Van Diemen's Land, one from New Zealand, one from Belgium, one from the Cape of Good Hope, one from Canada, and one from the United Kingdom.
The substance from which pure tannin is most frequently obtained for chemical purposes is nutgalls, for tannin constitutes above 40 per cent, of their weight. It may be procured also from several other sources, such as oak, horse chestnut, sumach, and cinchona barks, catechu, kino, &c.
The basis of the skins of animals is composed of a substance to which the name of gelatine is given. One of the properties of this substance is, that when combined with tannin, it forms the compound of tannate of gelatine, or leather, a substance which is so useful to mankind. From time immemorial, the substance employed to furnish the tannin to the hides of animals, in order to convert them into leather, has been oak bark. But as the purpose for which oaks are grown is their timber, and not their bark, the supply of oak bark cannot be calculated upon, and this is, perhaps, one of the causes why tanning as an art is in such a backward state.
The consumption of tannin required in the leather manufacture may be estimated from the fact that more than 672,000 cwts. of raw hides were imported in 1851, besides the hides of the cattle, &c., consumed in the United Kingdom. On the Continent and in the United States the consumption of bark for this purpose is also considerable.
The imports of bark for the use of tanners and dyers has amounted yearly to the very large quantity of 380,674 cwt., besides what we obtain at home. Oak bark contains usually the largest proportion of tannin, and according to Davy's experiments eight-and-a-half pounds of oak bark are equivalent for tanning purposes to two-and-a-quarter of galls, three of sumach, seven-and-a-half of Leicester willow, eleven of Spanish chesnut, eighteen of elm, and twenty-one of common willow bark. Tannin obtained from these sources, however, differs materially in some of its characters. The tannin of nutgalls, which is that generally employed for chemical purposes, is sometimes called gallo-tannic acid, to distinguish it from other species.
Notwithstanding the number of different substances which have from time to time been introduced for the use of tanners, it is, nevertheless, pretty generally acknowledged that there is nothing superior, or even equal, to good oak bark, and that all attempts to hurry the process beyond a certain point by the use of concentrated solutions of tan, &c., are for the most part failures, as the manufacture of good leather, to a great extent, depends on the process being conducted in a slow and gradual, but—at the same time—thorough and complete matter.
Oak bark is, however, by no means the only astringent bark well suited to the use of the tanner, and in various parts of the world other similar substances are used with very great success. All these tanning materials, though they may not be considered by the English tanner equal to the best oak bark, are, nevertheless, of great value to him; they may be employed in conjunction with oak bark, or even as a substitute in times of scarcity, or when the price of oak bark is high; in fact the very existence of such substances tends to keep down and equalise the price of bark, and to prevent it from undergoing those great fluctuations in value which would necessarily occur were it the only tanning material available to our manufacture—("Prof. Solly in Jury Reports of Great Exhibition.")
There are a vast number of bark and other substances useful for tanning purposes, which are found in the tropics, that are comparatively unknown or little regarded in Europe; but which might be readily obtained in large quantities and at a trifling cost. The bark of many species of Acacia furnishes the tanning principle in a great degree, particularly that of A. arabica, which, under the name of Babul wood, is largely used about Scinde, Biliary, Gruzerat, and other parts of India; where it is regarded as a powerful tonic. The fruit of A. vera, termed Egyptian and Senegal "bablah," has been employed in tanning and dyeing. Numerous species of this tribe are found abundant in New South Wales and the Cape Colony, and these, particularly the wattle bark of Australia, are in common use for tanning, from their astringent properties. The bark and rind of the fruit of the pomegranate (Pumica Granata) have similar properties.
The bark of Avicenna tomentosa is in great use in the Brazils for tanning. So are the curved pods of Cæsalpinia Coriari, in the East and West Indies, under the name of Divi-divi. Coriaria myrtifolia is not only used in tanning leather, but also for staining black. It is worth £9 to £10 per ton. Pterocarpus marsupium furnishes about Tellicherry the concrete exudation called kino, a powerful astringent used for tanning.
The plants of the mangrove tribe, Rhizophora Mangle, and other allied species, have frequently an astringent bark, which is in many cases used for tanning and dyeing black. This tree is very common in most tropical countries, where it forms dense thickets on the muddy banks of rivers and the sea shores. The bark of Bauhinia variegata, is made use of in Scinde and other parts of Asia. The bitter astringent bark and the galls of several of the Tamarisk tribe are also well suited for the purpose.
Mesembryanthemum nodiflorum, one of the numerous indigenous species of the Cape, is used in making morocco leather.
The extract procured from the bark of the Butea, that of the Buchanania latifolia, the Scyzgium (Calyptranthes), Jambolana, &c., are likely to be of consequence to the tanners, and could be produced in India in large quantities. Specimens of these, and of the bark of the Saul tree, of Nychanthes arbortrista, Terminalia angustifolia, and of the gaub fruit (Diospyros glutinosa), were shown by the East India Company. The bark of the hemlock tree is extensively employed for tanning in New Brunswick.
The bark of yellow hercules (Xanthoxylum ochroxylon), and the pods of Acacia tortuosa are used for tanning in the West Indies.
In the instructions given by the Admiralty to Sir James Boss, when proceeding on his Antarctic Expedition, his attention was particularly called to the astringent substances adapted for tanning, and to the various extracts of barks, &c., imported into England from our Australian settlements, and which are employed by the tanner. Little sterling information has as yet been obtained as to the qualities of the astringent gums, barks, and dyes, yielded in such abundance by the trees of those colonies, and the proportion of tannin they contained.
In 1846, 563 tons of bark for tanning were exported from Port Phillip.
A large quantity of tannin is extracted from various species of Eucalyptus, the gigantic gum trees in Australia and Van Diemen's Land (of which quarter all the species are natives), and sent to the English market; it is said to be twice as powerful in its operations as oak bark. Some of these trees attain a height of 200 feet. Their bark separates remarkably into layers. A sort of kino gum, an astringent resinous-like substance, is also extracted from E. resinifera, the brown gum-tree of New Holland, which is sold in the medicine bazaars of India. It exudes in the form of red juice from incisions in the bark. A single tree will often yield 60 gallons. In Brazil they use the bark of Luhea panicata, an evergreen climber, for tanning leather; and in Peru the bark of some species of Weinmaunia serve the same purpose. Among other powerful astringents I may notice the root of a species of Sea Lavender (Statice Caroliniana), Myrica cerifera, and Heuchera Americana, all natives of North America. Also the petals of Hibiscus Rosa-sinensis, a native of Asia.
The sea-side grape (Coccolaba uvifera) yields an astringent substance, known as Jamaica kino.
The bark of the Cassia auriculata, and the milky juice of the Asclepias gigantea, are used for tanning in India.
The red astringent gum obtained from Butea frondosa, a middling size tree, common in Bengal and the mountainous parts of India, is used by the natives for tanning. English tanners, however, object to its use on account of the color which it communicates to the leather.
The barks of the Mora excelsa, Benth; Courida (Avicenna nutida), cashew (Anicardium occidentale), guava and hog-plum (Spondius lutea, Linn.), have all been successfully used for tanning in Demerara and the West India Islands, where they are very abundant. Specimens were sent from British Guiana.
The root of the Palmetto palm (Chaemaerops Palmetto) is stated to be valuable for the purposes of tanning. The leaves of Nerium Oleander contain tannic acid. The bark of a species of Malphigia is much used by the Brazilians.
The panke (Gunnera scabra) is a fine plant, growing in Chili, on the sandstone cliffs, which somewhat resembles the rhubarb on a gigantic scale. The inhabitants eat the stalks, which are subacid, tan leather with the roots, and also prepare a black dye from them. The leaf is nearly circular, but deeply indented on its margin. Mr. Darwin measured one which was nearly eight feet in diameter, and therefore no less than twenty-four in circumference. The stalk is rather more than a yard high, and each plant sends out four or five of these enormous leaves, presenting together a very noble appearance.
The barks replete with the tanning principle should be stripped with hatchets and bills from the trunk and branches of trees in spring, when their sap flows most freely. The average quantity of oak bark obtained from our forests is estimated at 150,000 tons annually, of which Ireland and Scotland furnish but a very small quantity.
The following table, given by Dr. Ure, shows the quantity of extractive matter and tannin yielded by different substances:—
| In 480 parts | In 100 parts | |
| by Davy. | by Cadet. | |
| Sicilian sumach | 78 | — |
| Malaga ditto | 79 | — |
| Souchong tea | 48 | — |
| Green tea | 41 | — |
| Bombay catechu | 261 | — |
| Bengal ditto | 231 | — |
| Nutgalls | 127 | 46 |
| Bark of pomegranate | — | 32 |
| Bark of Virginian sumach | — | 10 |
| Bark of Carolina sumach | — | 5 |
Catechu and Gambier are very valuable for tanning, and are alluded to under the heads GAMBIER and ARECA PALM.
CATECHU is obtained from the Acacia Catechu, an arboreous tree growing from fifteen to twenty feet high, with a brown and scabrous bark. The interior wood is brown, dark red or blackish, and the exterior white, one or two inches thick. It inhabits various parts of the East Indies, of which it is a native, and is also now common in Jamaica. It bears whitish or pale yellow flowers.
The catechu obtained from this tree in Pegu, is celebrated throughout India, and fetches £4 to £5 more per ton than gambier and other astringent extracts. When of good quality, catechu is more powerful as an astringent than kino. Of all the astringent substances we know, catechu appears to contain the largest proportion of tannin, and Mr. Purkis found that one pound was equivalent to seven or eight of oak bark for tanning leather.
The term catechu, observes Dr. Pereira, is applied to various astringent extracts imported from India and the neighbouring countries. A few years ago the terms catechu, terra japonica, and cutch were employed synonymously; they are now, however, for the most part used in trade somewhat distinctively, though not uniformly in the same sense. The manufacture of catechu from the Acacia catechu as practised in Canara and Behar, has been described by Mr. Kerr ("Med. Obs. and Inquiries," vol. v.), and Dr. Hamilton ("Journey through Mysore," &c., vol. iii.), while Professor Royle has explained the process followed in Northern India. According to the last-mentioned gentleman, "the kutt manufacturers move to different parts of the country in different seasons, erect temporary huts in the jungles, and selecting trees fit for their purpose, cut the inner wood into small chips. These they put into small earthen pots, which are arranged in a double row, along a fireplace built of mud; water is then poured in until the whole are covered; after a considerable portion has boiled away, the clear liquor is strained into one of the neighbouring pots, and a fresh supply of the material is put into the first, and the operation repeated until the extract in the general receiver is of sufficient consistence to be poured into clay moulds, which, in the Kheree Pass and Doon, where I have seen the process, are generally of a quadrangular form. This catechu is usually of a pale red color, and is considered there to be of the best quality. By the manufacturers it is conveyed to Saharunpore and Moradabad, whence it follows the course of commerce down the Ganges, and meets that from Nepaul, so that both may be exported from Calcutta."
GAMBIER.
The Gambier plant (Uncaria Gambler, Roxburgh, Nauclea Gambir, Hunter), has been described by Rumphius under the name of Funis uncatus. It is a stout, scandent, evergreen shrub, which strongly resembles the myrtle. It is generally cultivated in the same plantation with pepper, as the leaves and shoots, after undergoing the process by which their juice is extracted, to furnish a kind of catechu, are found to be an excellent manure for the pepper vines. The leaves and young shoots of the gambier plant are collected as soon as they have attained a sufficient size, and boiled in iron pans until the juice acquires the consistence of treacle. The decoction is poured out into narrow troughs, dried, and afterwards cut up into small cakes, and packed in baskets for exportation. The gambier extract, which is of a yellowish brown color, and has the consistence of hard cheese, is much esteemed by the Malays for mixing with the preparation of betel, which they are in the habit of chewing; and considerable quantities have lately been imported to this country, where it is used for dyeing colors, and for tanning leather. The demand for gambier here is on the increase; and when better known to our chemists, it will probably be found applicable to many other purposes than those to which it is at present applied.
There were, in 1850, 400 gambier and pepper plantations on the island of Singapore; each measures or occupies on an average an area of 500 fathoms square, and employs eight to ten hands to cultivate and manufacture the gambier and pepper. There are some pepper plantations in addition, and they have been found to answer very well without any gambier being cultivated with them. Gambier cultivation is generally a losing undertaking, but it is adopted to obtain the refuse of the leaves for manuring the pepper vines, and also to employ the people in the plantations; it besides affords the proprietors the means of getting monthly sums to carry on the cultivation of pepper, which affords two crops yearly. There were formerly 600 plantations in Singapore, but the reason already assigned, and the formation of spice plantations contiguous have caused the abandonment of all those near the town. Each plantation must have an equal extent of forest land to that cultivated with gambier and pepper, to enable the manufacture of the gambier being carried on, and each gambier plantation, of 500 fathoms square, contains about 3,500 pepper vines, which yield on an average two catties per vine, or 70 piculs of pepper, and about 170 piculs of gambier annually;—a good plantation will, however, yield sometimes as much as 120 piculs of pepper, and 200 piculs of gambier, and a bad one as little as 40 to 50 piculs of pepper, and 60 to 80 piculs of gambier. Were it not for the enormous commission charged by the agents of these plantations, from whom the cultivators get all the advances, it would prove a profitable cultivation. The rates of commission charged generally are as follows:—Per picul of gambier, fifteen to twenty-five cents; per picul of pepper, thirty to forty cents; and if the price of the former is below one-and-a-half dollars, and the latter below three-and-a-half dollars per picul, a small reduction is made in the rates of commission. On every picul of rice supplied to the planters twenty to twenty-five cents commission is charged; this includes the interest of money advanced, which is never charged. A gambier and pepper plantation is valued or estimated at about 400 dollars on an average. The following is supposed to be a correct estimate, on an average, of the yearly expenditure and returns of a gambier and pepper plantation of 500 fathoms square, viz:—
| EXPENDITURE. | |||||
| drs. | c. | men. | drs. | c. | |
| Eight men at 3½ dollars and 7 Java rupees per month, wages for headman and labourers respectively | 22 | 70 | .. 12 .. | 272 | .40 |
| Five piculs of rice, including commission, say | 6 | 50 | .. 12 .. | 81 | 60 |
| Fish, &c. | 5 | 00 | .. 12 .. | 60 | 00 |
| Boat or cart hire to carry rice and produce | 1 | 75 | .. 12 .. | 21 | 00 |
| 435 | 00 | ||||
| PRODUCE. | |||||
| 170 piculs of gambier, valued at l dollar 45 cents per picul, less 15 cents commission chargeable, nett | 221 | 30 | — | — | |
| 70 piculs of pepper, at 4½ dollars, less 40 cents per picul commission, nett | 287 | 00 | 508 | 00 | |
| Yearly profit, 73 dollars, or about £15. | |||||
Several gambier and pepper plantations have been abandoned in Singapore, partly from the ground being impoverished, but more particularly from the exhaustion of the forest adjacent to their estates. The exhaustion of the trees by yearly consumption deprives the planters of the necessary fire wood which is used for the boiling down of the gambier. A gambier plantation gets exhausted in fifteen years, either from the want of firewood or the land getting impoverished.
There are about 200 plantations at Johore, and the produce of gambier for the season of 1851 was calculated at 30,000 piculs.
This shrub was, at one period, cultivated with success at Pinang and other places to the eastward, but as Java was the principal market for the produce, and the Dutch had levied a duty of twelve Java rupees per picul on it, the cultivation at the former island did not repay its cost, and it was accordingly abandoned. Prices have been lately advancing, and the Chinese are talking of trying it again. The plant is partial to hilly land or slopes at the skirts of hills. Two hundred plants are usually placed on one orlong of land, being six feet asunder. They are raised from seed, and are topped to eight or ten feet, when the gambier is to be prepared. The Chinese dry the seed slightly, and sow in rainy weather.
The seeds vegetate in forty days, and are planted out in the second or third month afterwards.
At the expiration of fourteen months, the first cutting of the branches, with the leaves on, is made. These are put into a boiler, and when the juice has been extracted, the branches and refuse are thrown away, and the boiling is continued until the liquor has obtained the proper consistence, when it is put into shallow troughs, dried, and cut into slices for sale. The second cutting takes place eight months subsequently to the first. The plant now grows strong and admits of frequent cropping, and it will endure for twenty years. No manure is used, but the plantation is kept clean.
Estimated cost of cultivating ten orlongs, about 13 acres, according to Colonel Low:—
| Spanish dollars. | |
| Value of cleared land, ten orlongs | 200 |
| Six laborers per annum | 360 |
| Quit rent | 7 |
| Boilers, firewood, and implements | 20 |
| Houses | 50 |
| Incidental | 30 |
| Total first year | 667 |
| Second year | 397 |
| 1,064 |
The six laborers on the plantation will, after the above period, be constantly employed in cutting and preparing the gambier: the average product will be 15 piculs monthly, which, at two dollars per picul, will be 30 dollars monthly, or 360 dollars per annum. This is the account obtained by collating different Chinese statements.
The Nauclea Gambir is placed by Jussieu under the natural order Rubiaceæ; it is a shrub attaining the height of six to eight feet, branchy; the leaves are ovate, pointed, smooth, waving, distinctly veined transversely underneath, of dark green color, and, when chewed, they have a bitter astringent taste, leaving however, afterwards, a sweetish taste in the mouth, not unlike liquorice; the flowers are aggregate, globular, composed of numerous florets, crowded on a globular naked receptacle; tubes of the corolla of a pinkish color; the upper part of the corolla fine, cleft, and of a greenish yellow color; the staminæ are five in number, and short; the pistil is longer than the corolla; the flowers are destitute of fragrance; the capsules (as correctly stated by Mr. Hunter) are stalked oblong, incrusted, and crowned with a calyx; tapering to a point below; two celled, two valved, the valves adhering at the apex, splitting at the sides; seeds very numerous, oblong, very small, compressed, furnished at both ends with a membraneous pappus.
The gambier plant is propagated either by seeds or cuttings, but the latter are preferred. It is cultivated to some extent at Singapore, but it is said that the gambier can be imported cheaper from the islands in the vicinity, more especially at the Dutch settlement at Rhio. The extract is used extensively by the natives of India, Eastern Archipelago, Cochin-China, and Cambodia, as a masticatory, wrapped up with the betel.
There are three different qualities of extract; the first and best is white, brittle, and has an earthy appearance when rubbed between the fingers (which earthy appearance gave it the name of Terra Japonica, being supposed, at first also, to come from Japan), and is formed into very small round cakes. This is the dearest sort, and most refined, but it is not unfrequently adulterated with sago; this kind is brought in the greatest quantity from the island of Sumatra. The second quality is of a brownish yellow color, is formed into oblong cakes, and, when broken, has a light brown earthy appearance; it is also made into a solid cube form; it is sold in the bazars in small packets, each containing five or six. The third quality contains more impurities than the preceding, is formed into small circular cakes, and is sold in packages of five or six in the bazar.
The method employed in preparing the extract is thus correctly related by Finlayson:—"The leaves are collected three or four times a year; they are thrown into a large cauldron, the bottom of which is formed of iron, the upper part of bark, and boiled for five or six hours, until a strong decoction is obtained; the leaves are then withdrawn, and allowed to strain over the vessel, which is kept boiling for as many hours more, until the decoction is inspissated; it is then allowed to cool, when the catechu subsides, The water is drawn off; a soft soapy substance remains, which is cut into large masses; these are further divided by a knife into small cubes, about an inch square, or into still smaller pieces, which are laid in frames to dry. This catechu has more of a granular, uniform appearance than that of Bengal; it is, perhaps, also less pure."
The younger leaves of the shrub are said to produce the whitest and best gambier; the older, a brown and inferior sort. There are other species of Nauclea indigenous to Singapore, but they do not produce any extract.
Dr. Bennett has particularised four qualities of gambier:—
1. Small round cakes, about the size of a small lozenge. Color pale, purplish, yellowish, white.
2. Cubes, in which shape it is principally imported into England, and square prisms, or oblong pieces.
3. Circular discs, or short cylindrical pieces.
4. Cubical amylaceous pieces, of a darker brown than the other kinds.
Gambier is one of the most powerful of the pure astringents.
The chief places of manufacture are Saik, Malacca, Singapore, and Rhio or Bintang. Bennett, in his "Wanderings," says there are 60,000 plantations of gambier on this island. After that of Rhio, the next best gambier is that of Lingin. That used by the Malays, with the leaves of betel, in the same manner as cutch in other parts of India, is the finest and whitest; the red being stronger tasted and rank, is exported to Batavia, China, and England, for the purposes of tanning and dyeing. It is frequently adulterated with sago powder, but it may be detected by solution in water.
Large quantities of gambier are imported, under the corrupted name of cutch, into Calcutta, from Pegu. The quantity of gambier produced in Rhio, by the Chinese settlers, amounts to about 4,600 tons a year, about 2,000 of which are exported for the consumption of Java, the rest being sent to Cochin-China and other neighbouring countries.
Two methods of obtaining gambier are described. One consists in boiling the leaves in water, and in inspissating the decoction; the other, which yields the best gambier, consists in infusing the leaves in warm water, by which a fecula is obtained, which is inspissated by the heat of the sun, and formed into cakes.
The injudicious practice adopted by the Land Office in Singapore, of granting indiscriminate licenses, or "cutting papers" as they are formed, seems open to objection, and is driving many of the Chinese cultivators to the neighbouring island of Johore, where they readily obtain permission to cultivate, without obstruction, this important article of commerce. Parties of 300 or 400 at a time left in 1846. It appears that, under his permissive license, the squatter obtains permission to clear as much land as he possibly can, but the order does not define any extent beyond which no cutting should take place. The squatter clears as much land as the means at his disposal will allow, in the hope and expectation that the jungle contiguous to the cleared ground will be at his command for fuel—a supply of fuel, easy of access, and adequate to the number of plants grown, being indispensable to the culture and manufacture of gambier. When the time for gathering the leaves arrives, another squatter (perhaps from motives of envy or malice) obtains a "cutting paper," and commences clearing in close proximity to the already-formed gambier plantation; obviously depriving the owner of the fuel he has reasonably calculated upon. The established planter cannot of course eject the intruder from the land, since the latter possesses an equal right to it, in virtue of his "cutting paper," which, as it specifies no limits, leaves him the disposer or destroyer of the crop of the industrious planter. Instead of the present system, a better practice ought to be introduced, defining the boundaries to be included in a "cutting paper," and effectually preventing a trespass on the fuel-land of the industrious planter. This might easily be effected by specifying the number of acres, as well as the direction, in every clearing paper granted.
The average produce of gambier in Singapore is between 7,000 and 8,000 piculs monthly. The ordinary price is about 1¼ dollars per picul. A deficiency of rain, labor, or other causes, will occasionally reduce the annual produce from 90,000 or 100,000 piculs, to 60,000 or 70,000, and this diminished supply will raise the market price of the article probably 35 cents per picul. But, in addition to the effect occasioned by a deficient supply, there are other causes in operation exercising a powerful influence in reducing prices. Gambier was first exported in 1830, from Singapore, to the extent of 2,587 piculs, at 4½ dollars per picul. As a rival to bark it failed at so costly a price to meet with encouragement; the culture and manufacture consequently declined until 1834, when 1,858 piculs were shipped to England at a somewhat lower rate. The demand then became active, the exportations were at first multiplied, then doubled every succeeding year, until they reached, in 1846-47 no less than 173,117 piculs. The price has gradually declined to 1¼ dollars per picul, at which rate it displaces its rival, bark. This price, however, is unremunerative to the grower, so that, unless more encouragement offers, the supply will decline.
The number of Chinese employed in the cultivation, &c., of gambier and pepper in Singapore is about 11,000. Their rate of wages fluctuates with the price of gambier. If a picul of gambier realizes 1½ dollars, the monthly pay will be about three dollars; if gambier fetches two dollars, their pay will amount to four dollars in the month. The workmen who clean the plantation always receive a dollar less than those who cut and boil the gambier.
A good deal of gambier seems now to be grown in Java, for 58,305 piculs were exported from that island in 1843. A small quantity is taken by the Chinese ports, but whether as a masticatory or for tanning and dyeing I am not aware.
| £ | |
| 1840 | 611 |
| 1841 | 1,053 |
| 1842 | 768 |
| 1843 | 471 |
| 1844 | 1,153 |
| 1845 | 537 |
| 1846 | 824 |
| 1847 | 1,549 |
| 1848 | 1,095 |
| 1849 | 896 |
| 1850 | 265 |
| 1851 | 386 |
In the Customs' returns of imports to this country, two articles are enumerated, under the separate names of cutch and terra japonica; the former is catechu and the latter the produce of the gambier plant. The imports of gambier were, in 1836, 970 tons; 1837, 2,738 tons; 1838, 1,600 tons; 1839, 5,213 tons.
| Cutch. | Terra Japonica. | ||
| tons. | tons. | ||
| 1848 | Imported to the United Kingdom | 1,186 | 5,623 |
| " | Retained for home consumption | 765 | 5,102 |
| 1849 | Imported | 1,636 | 6,851 |
| " | Retained for home consumption | 869 | 5,400 |
| 1850 | Imported | 1,172 | 4,585 |
| " | Home consumption | 787 | 3,655 |
| 1851 | Imported | 2,401 | 4,783 |
| " | Home consumption | 2,020 | 4,431 |
| 1852 | Imported | 2,236 | 3,244 |
| " | Home consumption | 1,708 | 3,003 |
Catechu, imported under its Indian name of cutch, is brought over in bales or baskets of from one to four cwt., the price being £18 to £25 per ton. About 450 cwt. of terra japonica or gambier is annually imported into Hull from the East Indies. The imports of the two substances into Liverpool is about 900 tons. Gambier is only worth £13 to £14 the ton; a few years ago it fetched 26s. the cwt. The imports into the port of London average 1,500 tons annually.
4,679 bales, and 14,436 baskets of terra japonica were imported into Liverpool in 1851, and 14,000 bales and baskets in 1852. The imports of cutch were 10,290 bags, and 2,592 baskets, in 1851, and 11,873 bags and baskets in 1852; the prices, which were from 16s. 6d. to 18s. per cwt. for each article, in 1851, were rapidly run up in Liverpool, in 1853, owing to short supplies, to 25s. for gambier, and 22s. to 24s. per cwt. for cutch, or catechu.