^ ^ \ CONTENTS. Letter of submittal 4 Introduction 5 Classification of tanning materials 5 Tannins from woods 6 Quebracho 7 Tannin value of quebracho 9 Utilization of quebracho for tanning 10 Manufacture of quebracho extract 11 Process of extraction 12 Export of Argentine quebracho 13 Imports of quebracho into the United States 14 Other Argentine woods similar to quebacho ■ 15 Tannins from barks 16 Mangrove bark 16 Minor barks 19 Barks of Paraguay 19 Barks of Argentina 23 Barks of Brazil 24 Barks of Chile 24 Barks of Peru 24 Barks of Venezuela 24 Barks of Mexico and Central America 25 Barks of general occurrence 25 Barks of the West Indian Islands 25 Tannins from leaves 25 Tannins from roots, bulbs, and excrescences 27 Tannins from fruits and seeds 28 Divi-divi 28 Algarobilla 29 Minor fruits and seeds 31 Summary 32 3 LETTER OF SUBMITTAL. \\3> Department of Commerce, Bureau of Foreign and Domestic Commerce, Washington, February 27, 1918. Sir: Submitted herewith is a monograph on tanning materials in Latin America, prepared by Dr. Thomas H. Norton while he was a commercial agent of this bureau. The paper was submitted to the Second Pan American Scientific Congress, and was published in Volume VIII of the proceedings of the congress. As the edition of the proceedings is limited and its distribution confined mainly to libraries and Government offices, it has been deemed advisable to issue the paper in separate form, to make it more readily available to tanners and others interested in the leather industry. The monograph presents a comprehensive survey of the tannin- bearing plants and trees in South and Central America and Mexico, and reveals the resources of these countries, thus far only slightly exploited, for meeting the increasing demands for tanning mate- rials. Statistics of the Argentine quebracho industry have been brought down to the latest possible date. Respectfully, B. S. Cutler, Chief of Bureau. To Hon. William C. Redfield, Secretary of Commerce. 4 TANNING MATERIALS OF LATIN AMERICA. INTRODUCTION. Throughout the more densely populated regions of the earth the available supply of vegetable material for use in tanning is steadily diminishing. The importance of a more perfect and exact knowledge of the varied substances which contain tannin is now generally recognized. In not a few tropical and subtropical lands a more or less complete "census" of the trees and shrubs belonging to this category is now being taken. Few parts of our globe possess such a variety of tannin-bearing plants and trees as those included under the designation "Latin America." It is the purpose of this study to enumerate and describe as com- pletely as possible the known occurrence of such sources of tannin in the countries in question and to show the extent to which they are already utilized or are easily susceptible of exploitation. It is highly probable that in many cases the real economic value of these American tannin yielders has not been fully appreciated. I was led to this conclusion by the appearance during 1913 in a promi- nent organ of the leather industry of the following list : Geographical Distribution of the Important Tannin Plants. India 68 Europe 40 Australia 22 Canada and the United States 16 Africa 9 Central America 7 China 3 Japan 3 Chile 3 Brazil 3 Argentina 3 New Zealand : 3 Peru 2 Guiana 2 Asia 2 Mexico 1 It will be noticed at once from the above list with what painstak- ing care the sources of tannin in the British Colonial Empire have been studied. CLASSIFICATION OF TANNING MATERIALS. Tanning materials, in the broadest meaning of the term, include all substances capable of changing the skins of animals into leather. By this change the skin ceases to be liable to decay under ordinary conditions, becomes more or less soft and pliable, and is, as a rule, impermeable to water. 5 6 TANNING MATERIALS OF LATIN AMERICA. The materials used to accomplish these chemical and physical alterations in the nature of hides and skins, are found in all three kingdoms of nature. They are likewise found among the products of chemical industry. The mineral kingdom, for example, furnishes salt and alum, used for producing tawed or white leather. In many countries animal fats, and notably in the Americas the brains of deers, have been employed to make chamois or wash leather. Among chemical products such inorganic compounds as the salts of copper, iron, cerium, titanium, and notably of chromium, and organic aldehydes, especially formaldehyde, have all been used for tanning. The most important tanning materials are those derived from the vegetable kingdom. They include a great variety of woods, barks, ieaves, fruits, etc., containing in varying amounts the so-called tan- nins or tannic acids. These latter differ widely in chemical consti- tution and properties. They all possess in common the power of precipitating gelatin from its solution as an insoluble compound. They are also all derivatives of the aromatic series, containing either pyrocatechol, C c H 4 (OH) 2 , pyrogallol, C 6 H 3 (OH) 3 , or, somewhat rarely, phloroglucinol, the isomeride of the latter. The result of their action upon the hides of cattle is the production of the brownish, yellowish-brown, or reddish-brown leather of commerce. This paper will describe such occurrences of the tannins in the flora of Latin America as are actually or potentially of importance among the world's sources of tanning materials. It is manifestly impossible to include in any such list all tannin- yielding plants. A tabulation of that character would embrace a large part of the vegetable kingdom as represented in the indigenous growths of Latin America. For the sake of convenience these substances may be classified under the following heads : Woods, barks, leaves, excrescences, roots and bulbs, fruits and seeds. TANNINS FROM WOODS. The number of woods yielding tannin in sufficient abundance to warrant an industrial exploitation is exceedingly limited throughout the world. The woods of the oak and the chestnut form almost the only examples in the Northern Hemisphere. The past few decades have witnessed the rapid extension of the use in tanning of the quebracho wood of Argentina. It may now bo regarded as the most important tannin asset of the world. Its dominating position is revealed in the import statistics of the United States. During the fiscal year ending June 30, 1914, the tanning materials brought into the United States were valued at $3,864,000. Quebracho wood and extract constituted 87 per cent of the total. Quebracho, in fact, formed 38 per cent of all the tanning material used in the United States. It will thus be easily realized that, while the number of plants and trees in Latin America yielding notable amounts of tannin is limited, one of these plays the leading role in the world's leather industry. TANNING MATERIALS OF LATIN AMERICA. 7 QUEBRACHO. The name " quebracho " is derived from the Portuguese " quebrar," break, and " hacha," ax. Its literal meaning is " ax breaker." For- merly the term was applied to every hardwood tree in South America that dulled the chopper's tools. It is now used commercially in connection with but three trees, the true quebracho, the white que- bracho, and the red quebracho. The latter two are of no importance as sources of tannin. Much confusion has resulted from the indis- criminate use of the name for totally different varieties of wood. The true quebracho, Loxojjterygium or Qwbrackia lorenizii Griseb., belongs to the family of the Awacarcliacese, or cashew fam- ily, and to the genus Quehrachia. It is found in Argentina, Bolivia, Brazil, Paraguay, and Uruguay. The more specific habitat is a district extending eastward some 500 miles from the Andes Mountains, and reaching northward from near the mouth of the Parana Elver for a distance of about 600 miles. The area of this district is, roughly, 300,000 square miles. The terri- tory in which the tree is industrially exploited includes the northern portion of Argentina and the Province of Chaco in Paraguay. At the present rate of consumption, it is estimated that the annual cut of quebracho is much less than the sum total of annual growth. The total available supply is estimated at 168,000,000 tons. Less than 1,000,000 tons are cut annually at present. The quebracho is never found in pure stands. It is scattered through open forests containing, as a rule, a large variety of species. It is rare to encounter more than five quebracho trees per acre. In consequence of this scattered occurrence, it is necessary to cut annually over about 500,000 acres of forest land in order to secure the quantity required to meet the demands of the world's markets. The value of the quebracho forest land is quite variable. In Argen- tina, when near a railroad, it commands $2 or more per acre. In Paraguay the average price is $1.50 per acre, although there are cases where the rate is as low as 15 to 25 cents per acre. The favorable location for the quebracho tree is on slightly ele- vated ridges lying between watercourses. A sandy soil, with moder- ate atmosphere but abundant soil moisture, seems also conducive to growth. Where conditions are very favorable, trees are encountered rang- ing in height from 50 to 75 feet and varying in diameter from 2 to 4 feet. Ordinarily the trees are 18 to 36 feet in. height and 18 to 40 inches in diameter. The best wood is found in the virgin forests along the Parana River and the Picole Majo River. Thus far, the tree seems to be immune against the attacks of insects. When first felled, the sapwood is of a light yellow color. On ex- posure to the sun it assumes a light-red tint. The hardwood, when freshly cut, is of a dark, cherry-red color. This deepens with age. Quebracho wood ranks among the heaviest and hardest woods known. It is the most durable wood found in Argentina. Highly tempered tools are needed to work it, even when in the green state. After complete seasoning it is exceedingly resistant to cutting tools. The specific gravity ranges from 1.27 to 1.38. Ordinarily, 1 cubic foot weighs 78 pounds. TANNING MATERIALS OP LATIN AMERICA. Distribution of the quebracho tree (Quebrachia lorcntzii). TANNING MATERIALS OF LATIN AMERICA. 9 As the quebracho wood is fine-grained and takes a beautiful polish, it possesses a pronounced commercial value and is employed locally for a great variety of uses — for cabinetmaking, house construction, etc. It does not appear, however, that for such purposes it ranks above other hardwoods occurring in Argentina. Apart from its chief use as a source of tannin, it has been in abundant demand in Argentina for many years as a satisfactory material for railroad ties. Nine such ties weigh 1 ton. These ties remain on a roadbed indefinitely in a state of perfect preservation. It has been assumed that the large amount of tannin present acts as a preservative and causes the durability. Ties now in use for 25 years are absolutely sound. Throughout the region of occurrence, the quebracho ties are gradu- ally replacing the iron or steel ties hitherto used in railroad con- struction. The standard ties on the Argentina broad-gauge railway are 9 feet long, 10 by 13 inches cross section. They cost $2 to $2.50 each. On account of the hardness of the wood spikes can not be driven into it. Holes are therefore bored and bolts are employed to fasten the rails. The chief drawback to the use of quebracho wood for this purpose is the almost total lack of resilience. There is also a marked tend- ency to crack when exposed to frost. The necessity of boring holes for the bolts used makes an additional expense. Experiments have been started in the United States to test the desirability of quebracho ties for our railways. The quebracho timberland of Argentina yields, on an average, 18 ties per acre. American white oak or pine forests yield from 40 to 60 ties per acre. TANNIN VALUE OF QUEBEACHO. The tannin content of the different parts of the quebracho tree varies somewhat with the region where it grows. Numerous analyses give, ordinarily, the following results: Per cent of tannin. Heartwood 20-24 Sapwood 3- 4 Bark 6- 8 One analysis from the Gran Chaco district shows an unusually high tannin content : Per cent. Tannin 28. 20 Foreign substances extracted 1. 70 Extract ash : . 40 Water , 11.85 Insoluble matter 57. 85 Jean (Bull. Soc. Chem., 1880, 33, 6) found that the tannin of que- bracho was distinctly different from that of oak bark or chestnut wood. In 1903, Procter (Leather Manufacture, 269) showed that a red phlobophane was present in the tannin, and that it contained catechol and phloroglucinol nuclei. In 1906, Strauss and Geschwender (Zeitschr. f. angew. Chem., 19, 1121) isolated the pure tannin, free from phlobophanes. It 48022°— 18 2 10 TANNING MATERIALS OF LATIN AMERICA. formed a light, flaky mass, easily becoming sticky when exposed to the air on account of its hygroscopic character. They consider it as identical with maletto tannin, found in the bark of various species of eucalyptus, notably Eucalyptus occidentalism and with the tannin extracted from cinchona bark. It received the formula of C 43 H 50 O 20 . Nierenstein (Collegium, 1905, 65, and Ber. d. deut. ch. Gesell., 1907, 40, 4575) regards the quebracho tannin as consisting of a mixture of three distinct tannins. From quebracho phlobophane, on dis- tillation with zinc dust, he obtained anthracene. Incidentally, this reaction is worthy of more extended study, as offering a source of hydrocarbon for use in the manufacture of alizarin. It is definitely established that a considerable amount of the tan- nin extracted from quebracho is but sparingly soluble in cold water, and is partly deposited when hot aqueous solutions are allowed to cool. There is still much to be done in clearing up the exact chemical nature of the tannin content of quebracho, and it is to be hoped that .the problem may be solved in a final manner. It is highly probable that a more exhaustive study may pave the way for removing the difficulties attendant upon the use of quebracho extract alone for tanning purposed. In this connection, it may be noted that quebracho wood contains a fine yellow dye, fisetin, identical with the dyestuff present in young fustic. It is present as a glucoside combined with tannic acid. The colors obtained from fisetin are, unfortunately, somewhat fugitive to light. Mention may also be made of the " quebracho resin," which collects as a thickened juice in crevices of the tree. UTILIZATION OF QUEBRACHO FOR TANNING. It is worthy of note that, as a rule, the sapwood of the quebracho tree and its bark are completely neglected as sources of tannin, and are allowed to go to waste. When we consider that chestnut wood contains but 3 to 6 per cent of tannin, that oak wood contains but 2 to 3 per cent, that the tannin content of oak bark is often as low as 8 per cent, and yet know that- all three are profitably employed on a relatively large scale as sources of tanning extracts, it is a mat- ter of surprise that these two constituent portions of quebracho logs should be entirely neglected, when once in the possession of extract factories. There would appear, also, to be a distinct field for experimentation on the characteristics of the tannins formed in the sapwood and in the bark of the quebracho tree. It is not impossible that they may be free, to some extent, from certain disadvantages attending the use of the tannin obtained from the heartwood. Almost invariably, the tannin present in the heartwood is extracted by boiling with water, and the concentrated extract is used for tanning purposes. The special field of usefulness for quebracho in the production of current forms of leather has now been quite clearly defined. In regard to color, quebracho alone does not seem to impart any distinctive tint. However, when alum and salt are added to the bath, finer results are obtained than when gambier is employed. The resultant leather is of a handsome, pale, straw-colored grain on the exterior surface, while the flesh side remains almost white. TANNING MATERIALS OF LATIN AMERICA. 11 Quebracho adds weight and firmness to the tanned product. It yields a light leather well adapted to take on all varieties of dyes, and also heavy leathers of excellent quality. Its chief advantages lie in its cheapness and in the ability to effect rapidly a thorough tanning, very marked in the case of certain forms of leather. It is particularly adapted to tan hide promptly and to facilitate the absorption of the very strong liquors employed in the final stages of tanning. On account of the absence from quebracho extract of certain non- tanning substances, occurring ordinarily in the extracts of most tan- nin-yielding plants and trees, it fails to produce, alone, the highest grade of leather. It is therefore ordinarily mixed with other tan- ning materials, such as the extract of mangrove, or chestnut or oak bark, all of which are rich in nontannins. When combined with oak bark especially, the results are most satisfactory, the cost of tan- ning is very notably decreased, and the leather obtained is equal, in every respect, to that made by the use of pure oak liquor. MANUFACTURE OF QUEBRACHO EXTRACT. The cost of cutting quebracho logs and conveying them to the extraction factories, or to points of shipment by rail or water, is usually much greater than the cost of preparing the extract. Ordi- narily, after a tree is felled, the logs (16 to 32 feet in length) are freed from bark, sapwood, and branches, and hauled by ox team to the nearest factory or railway station or landing place on a river. This transportation of the logs is especially difficult and expensive in Paraguay, where there is no local market for the wood or the extract, As a rule, the Paraguay quebracho is largely shipped to Buenos Aires. The best timber is frequently reserved for building purposes, for cabinetmaking, etc. The culls, or second-quality wood, are employed for extractive purposes. The extraction industry is very effectively organized in Argentina, some of the companies being quite well financed. The recent consoli- dation of the Forestal Co. and the Santa Fe Land Co. has placed in the control of a single corporation a capital of $10,000,000 and an area of forest land exceeding 6,000,000 acres. One large Argentine plant has a monthly output of 1,000 tons of extract; another produces monthly 600 tons. There are quite a num- ber with a monthly output of from 200 to 300 tons. All are equipped with modern extractive apparatus, chiefly of German construction. Some of the companies were engaged, until recently, in supplying railroad ties. They have discovered that the same amount of wood, which yields ties worth $3.50, supplies extract worth from $10 to $12. In the larger factories, the daily consumption of water reaches sev- eral thousand cubic meters. Some factories are located in regions destitute of pure, fresh water for the purpose of extraction. As a result, all water required for such use must be purified by distillation. On the upper Paraguay River there are five plants for making quebracho extract, and the machinery is nearly all of German origin. The capital invested is partly German, partly Argentine. During 1912, these factories all ceased operations. This action caused a financial panic, as the output of the five works brought into the country monthly over $100,000 of foreign money. Since the out- 12 TANNING MATERIALS OF LATIN AMERICA. break of the present war, the price of extract has practically quad- rupled and three of the factories are again in active operation. PROCESS OF EXTRACTION. In most of the extractive factories of Argentina and Paraguay, the quebracho logs are first reduced to chips and shavings, by ma- chines similar to those used for dyewoocls. It is stated that, in some cases, the logs are split into boards, and that the spent boards are used later for fence posts, beams, paving blocks, railway ties, etc. The sole use for spent material in American works is as fuel. The most approved device for chipping the quebracho consists of revolving cylinders faced with strong knives. As the logs are pressed against these cylinders, the wood is sliced transversely to the grain, into chips about one-eighth of an inch in length. Formerly, extraction took place in open wooden vats, similar to those customarily employed for the extraction of sumac. The re- sultant liquor, obtained by diffusion, was better colored, as there was no decomposition of tannin, in consequence of the use of heat. The leaching was, however, very imperfect. Now, closed extractors of copper are in general use. Some of these extractors have a capacity of 15 cubic meters (530 cubic feet). Steam is admitted directly. The operation is rqpid, and very concentrated liquors are obtained in place of the dilute solutions secured by diffusion batteries. These concentrated liquors show a strength of 20° B. upward. As a rule, they are cooled by circulation through a system of pipes, and are clarified by being allowed to stand for some time at a tem- perature of 15° C. until most of the insoluble sediment has been de- posited. During this operation, light and air are excluded in order to prevent oxidation and a resultant darkening of the liquor. For a'more complete chemical clarification and decolorization, vari- ous substances are in current use, such as. animal blood, lead nitrate, alum, sulphurous acid, sulphides, and resin soap. The use of a resin soap solution, with finely powdered lead sulphate or barium sulphate, seems to give fair results. Better results, however, are ordinarily obtained by the Tagliani, or alkaline sulphite^ method. Until this process was introduced, the use of quebracho extract was frequently attended by the formation on hides of a slimy precipitate, which very materially delayed the operation of tanning. An adequate treatment with sodium sulphite effectually removes the matters which give rise to this precipitate. All the above reagents cause the liquor to assume a much lighter tint. After clarification and decolorization, the quebracho extract is evaporated in vacuum pans to a sirupy consistency. These liquid extracts contain from 50 to 60 per cent of water and have a density of from 20° to 30° B. The Yaryan evaporator is largely used for concentration to 20° B. Sometimes the evaporation is carried so far that but 20 to 25 per cent of water remains. The resultant extract, on cooling, is solid. It is to be noted, in connection with the general process of extrac- tion, that from 91 to 93 per cent of the tannin present in quebracho wood is extracted, and that but a small amount of nontannins enter into solution. In the Argentine factories, but little attempt is made to carry the extraction beyond the point at which about 3 per cent of tannin remains in the spent wood Pi u 1> o a a crt .*. -a ia -,. "M a !fl ■rt a> •a •-a £ ^ £ a --j "2 a, S * as o 3 Eh aj s*^ *> _ i— i M) 1- 13 J o y> p-a e sj o •sS a o a a a, ,. s a E °5 m a ■ « 5 .")..t, &s P* 5 w ci 3 & o a O fcfl 0) o § M £ TANKING MATERIALS OF LATIN AMERICA. 13 In the commercial extracts and pastes, it is found that there is a considerable amount of tannin present which is not soluble in strong tanning liquors. This is an exception to the ordinary rule. In all other tannin extracts, the entire quantity of tannin present is soluble in the strong liquors. A typical sample of quebracho extract, on analysis, showed : Per cent. Tannin, soluble 64. 5 Tannin, insoluble 8. Nontannins 7. 5 A set of comparative analyses of a liquid extract and of a paste gave the following results : Constituents. Extract. Paste. Water Tannin Nontannins Ash Insoluble Carbohydrates Parts of carbohydrates present to 100 parts tan n hi Per cent. Per cent. 43.6 18.7 48.3 70.4 3.8 7.9 1.6 1.5 2.6 1.6 1.5 1.8 3.1 2.6 The growth of the quebracho industry has been relatively rapid. The wood was first seen in Europe at the Paris Exposition of 1867. By 1871 several firms in Havre and Antwerp were using it regularly. In 1876 it was supplied to tanners in Switzerland and Alsace, and along the Rhine. At about the same time the use in Argentine tan- neries assumed notable proportions. The importation of quebracho wood into Europe began on a large scale in 1888. Germany became at once the leading consumer, using the new material largely in the production of sole leather. It was partly due to this factor that German sole leather began at that date to supplant the American article. In 1876 the United States exported sole leather to Germany to the extent of 6,400,000 pounds. In 1886, the export had sunk to 2,000,000 pounds. In 1906 the export was 205,000 pounds. The growth of the Argentine export of quebracho wood and ex- tract is shown in the following table : Value of Exports of Argentine Quebracho. [Values are given in Argentine pesos: 1 peso equals $0,965 U. S. currency.] Years. 1880. 1881. 1887. 1890. 1891. 1892. 1893. 1894. 1895. 1896. 1897. 1898. 1899. 1900. 1901. Extract . $40, 167 68,419 120,474 119, 224 317, 156 595, 701 431,004 Logs. 910,121 11,016 5,095 172, 700 485,357 826, 508 1,245,628 617, 811 1,265,942 962, 687 1,778,814 832, 718 1,356,744 1,882,604 1,593,761 2,398,362 1, 989, 195 Years. 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 Extract. $909, 904 1,204,049 2,011,130 2,427,772 2,162,949 1,811,878 2,994,922 4,226,333 4,429,357 4,980,027 4, 836, 860 4, 974, 686 5,186,946 15,873,372 19, 663, 098 9, 966, 958 Logs. $2,477,233 2,002,010 2, 527, 227 4,275,164 3,425,101 3,132.493 2,962,1S4 4, 380; 033 5,604,430 6,897,435 3, 568, 557 4,988,349 9, 238, 745 2,684,408 2,321,747 1, 582, 554 14 TANNING MATERIALS OF LATIN AMERICA. In 1908 the total export of quebracho products from Argentina was 254,571 metric tons. The chief countries participating were : Metric tons. United Kingdom 205,065 United States 11,949 Germany : 8, 323 Italy 7, 282 In 1913 the total export of quebracho logs and extract reached 463,648 metric tons. The chief countries participating were: Metric tons. United Kingdom 83, 035 United States 37, 835 Italy 30, 144 Germany 27, 212 Belgium 8, 695 Austria-Hungary 43, 519 France 3, 891 In 1913 the value of quebracho products shipped from Argentina constituted 2 per cent of the total exports, and stood ninth in importance in the list of exported articles. The chief Argentina shipping port at that time was Colastine, on the Parana River. In 1916 the value of the quebracho products shipped from Argen- tina constituted 40 per cent of the total exports, and stood third in importance in the list of exported products. The chief shipping ports for quebracho in 1915 were Barranqueras (on the Parana River in the Territory of Chaco) and Buenos Aires. The relations of the American market to the Argentine exports are shown in the following table : Imports of Quebracho Wood and Extract into the United States, 1907 to 1917. Quebracho wood. Quebracho extract. Fiscal year. Tons, long. Value. Pounds. Value. 1907 66, 810 48, 871 66, 113 80,210 66,617 68, 174 102, 766 73,911 54,955 106,864 73,367 $840, 779 612,971 731, 795 1.058,647 984, 841 982,315 1,299,995 899,603 753,981 1,598,465 1, 274, 660 76,034,000 79,187,000 102,005,000 87,531,000 85,721,000 67,281,000 74,545,000 88,589,000 120, 450, 283 81,501,952 59, 808, 734 $2 320 000 1908 1909 1910 2,741,000 2,796,000 2,894,000 2,223,000 1,903,000 2,441,000 3,676,749 5,432,468 5,198,904 1911 1912 1913 1914 1915 1916 1917 The imports of South American quebracho wood and extract into Germany during the calendar years 1912 and 1913 were as follows: 1912. 1913. Quebracho wood, metric tons 106,451 117,081 Quebracho extract, metric tons 12, 158 17, 277 Exports of quebracho from Argentina to Germany in 1914, accord- ing to Argentine statistics, were: Wood, 10,875 tons; extract, 4,054 tons. The British imports of quebracho extract from Argentina aver- aged annually in value $163,000 during the five years 1909-1913. TANNING MATERIALS OF LATIN AMERICA. 15 In connection with the importation of quebracho into the United States, it is to be noted that no duty has ever been imposed upon the logs. Prior to October 3, 1913, there was a duty of one-half cent per pound on the extract when below 28° B., and three-fourths cent when in excess of that degree of concentration. Since the date above men- tioned, quebracho extract has entered the United States duty free. The price in 1912 of quebracho logs at Montevideo and at Buenos Aires, f. o. b., ranged from $14 to $20 per long ton. The extract was then quoted at $80 to $85 per long ton. In 1914 the logs destined for export to the United States cost on an average $12.17 per long ton at the port of shipment. The average cost of the extract at the same points was $61.04. In the fiscal year ending June 30, 1915, the average price of logs was $13.72 per ton, and of extract, $68.50. In September, 1915, the average price of the latter had reached $115 per ton, and the price of the logs was $14.98. OTHER ARGENTINE WOODS SIMILAR TO TRUE QLEBRACHO. There are several other varieties of forest trees in Argentina and the neighboring territories containing limited amounts of tannins which probably would be utilized as sources of tanning material were it not for the abundance of the true quebracho, with its exceptionally high tannin content. Allusion has already been made to two of these, bearing also the popular designation of " quebracho." The white quebracho, " quebracho bianco," Aspidosperma que- bracho bianco (Schlecht), belongs to the family of the Apocynacese, which includes common dogbane, or Indian hemp. It is very common wherever the true quebracho occurs. It is found most abundantly in the moister regions of northern Argentina. It is an evergreen tree, conspicuous for its erect stem and wide-spreading crown. The height frequently ranges from 60 to 100 feet, and the diameter ranges from 1 to 3 feet. It is easily distinguished from the true quebracho, as the branches occur nearer the ground, and the foilage is much less com- pact. The wood is strong, hard, and very heavy. The specific gravity varies from 0.88 to 1.1. It is very close grained. The color is yellowish white, with a noticeable pinkish or rosy tint. Although not very durable in contact with soil, it is extensively employed for a variety of forms of woodwork. The dense, compact structure ren- ders it an excellent substitute for boxwood in wood engraving. There is a marked tendency to warp and twist, unless care is taken in the seasoning. Unlike true quebracho, it is subject to insect attack. The wood contains about 3 per cent of a tannin, which is essentially the same as that found in the true quebracho. The leaves, on the con- trary, possess on an average 27.5 per cent of a tannin, which is almost colorless and is insoluble. The bark contains 4 per cent of tannin. It is used locally as a febrifuge. The red quebracho, " quebracho Colorado," Aspidosperma que- bracho Colorado (Schlecht), belongs to the same family as the white variety, and occurs in abundance wherever the true quebracho is found. The wood, when freshly cut, possesses a bright red color, which changes to a dark brown with age. It is used for the same purposes as the white variety. Although it is more durable in con- 16 TANNING MATEBIALS OF LATIN AMEBIC A. tact with the soil, its commercial value is less than that of the allied variety. Its tannin content is also quite low. Other members of the same family share with the above-mentioned varieties the property of hardness, and resemble them in appearance. They are: Asptdospermum chwneum, with 7 per cent of tannin; Aspidosperma peroba, with 5 per cent; and Aspidosperma sessiflora, with 4 per cent. The wood of the latter contains a pink coloring matter of possible usefulness. It is a tall, stout tree, at present neither well known nor much used. It is found chiefly in Paraguay, in a few localities, north of latitude 26°. Schinopsis halansce (Engl.), of Paraguay, is reported also to have a fair amount of tannin, and to be used locally. A member of the sandalwood family, lodina rJiombifolia (H. and A.), known as "quebracho flojo" or "" sombra de toro," is a hand- some evergreen tree, found occasionally in Argentina. Not only the wood, but also the bark, contains fair amounts of tannin. Machaerium fertile (Tipuana speciosa), known as "tipa," contains much the same amount of tannin in both wood and bark. The wood of Cedrela tubifiora, and other varieties of Cedrela, oc- curring in Paraguay, contains sufficient tannin to render it available for tanning purposes. They are members of a comparatively small genus in tropical South America, belonging to the bead-tree family (Meliacece) . The trees grow to a large size, and the wood resembles mahogany in appearance. The wood of young fustic, Rhus cotinus (Linn.), which occurs fre- quently in the West Indian Islands, contains a considerable amount of tannic acid in combination with the glucoside of fisetin, the hand- some but somewhat fugitive yellow coloring matter of this tree. No attempt commercially seems to have been made to utilize this source. It is worthy of note that cases are very frequent where tannins are accompanied by yellow coloring matters. Young fustic is cultivated to some extent in Italy, where the leaves are encountered in com- merce under the designation of Venetian sumac. They are fre- quently used for tanning purposes throughout southern Europe. The well-known logwood, Hcematowylon campecManum (Linn.), occurring in such abundance in Yucatan, Honduras, San Domingo, and Jamaica, is a similar example of the combination of a dyestuff with tannin. The value of the coloring principle is such that hith- erto there has been no attempt made to secure a tannin extract from the wood of this tree. TANNINS FROM BARKS. There is a much larger variety of tanning material available in the barks of different trees of Latin America than is the case with the woods. The amount of tannin extracted from quebracho wood alone is, however, much greater than the total obtained at present from all forms of bark, leaves, and roots. Many of these varieties of bark have an extensive local use in the different countries, especially in regions where the quebracho does not occur. Thus far they have not become of marked importance in international trade. MANGROVE BARK. The only possible exception to the above statement is found in the case of mangrove bark. The export of the bark from Venezuela, TANNING MATERIALS OF LATIN AMERICA. 17 and of the extract of the bark from Colombia, have recently become a factor of growing interest in connection with the world's supply of tanning materials. Hitherto the chief sources of mangrove bark have been Portuguese East Africa, Madagascar, and the East Indies (Celebes, Borneo, etc.). The bark of the mangrove growing naturally in these regions is regarded as distinctly richer in tannin than that found in South America, the content ranging from 38 to 48 per cent. The mangrove bark of South America comes chiefly from Rhizo- phora mangle (Linn.). Other varieties of Rhizophora, as well as of Ceriops, Avicennia nitida (black mangrove, or "courouda"), Avicennia tomentosa (white mangrove), Laguncularia, Conocarpits, and Cassipourea, have a certain importance in this connection. The mangrove jungles of tropical America fringe the tidal estu- aries, overrun soft marshes, and line low, muddy coasts. The trunks and branches emit in abundance adventitious roots which, descending in curves, reach the soil at some distance from the parent stem and give rise to new trunks. The method of expansion closely resembles that of a banyan grove. Another remarkable arrangement of nature for the propagation of the tree is connected with the germination of the seeds. While the fruit is still hanging to the boughs, long radicles emerge from the seeds and descend rapidly to the mud beneath. Here, the plumule soon makes its appearance and a new growth is established. Some of the fruits and seeds of mangrove trees are provided with special devices, which enable them to float easily, and to be transported to quite a distance. A novel character- istic is found in the " pneumatophores," or air roots. These are branches of the root proper which project from the mud. They are provided with minute openings, so-called stomata or lenticels, through which air enters, and penetrates, by means of passages in the soft spongy tissue, to the roots spread beneath the surface of the mud. The wood of some species is hard and durable. The fruit of the Rhizophora is sweet and wholesome, and serves to produce a light wine. It has a ruddy brown shell and a delicate white pulp. The percentage of tannin in the bark of mangrove trees is quite variable, ranging from 5 to 45 per cent. The proportion increases with the age of the tree. The bark encountered in commerce, or used for extraction in the country of origin, contains usually from 22 to 33 per cent. The tannin present can be isolated in the form of an amorphous, dark-red powder, which so closely resembles in its properties catechu- tannic acid that a possible identity is suspected. In practice, man- grove extract can be substituted with ease for catechu. A red- dish-brown coloring matter accompanies this tannin, and im- parts to leather a color quite similar to that resulting from the use of hemlock bark. It is worthy of note that the leaves of mangrove trees are also fairly rich in tannin. They are largely used in the tanneries of southern Brazil. On account of the rapid deterioration in properties during transportation, they are rarely exported. In the tanneries of Santa Catharina, mangrove leaves are the sole material used. The annual consumption is about 400 metric tons. In the two tanneries of Santos there was in 1902 an annual consumption of 1,800 cubic 18 TANNING MATERIALS OP LATIN AMERICA. meters of mangrove bark, and of 1,350 metric tons of the leaves. The same year, 1,000 metric tons of bark and 130 tons of the leaves were exported from the port of Santos. The bark is encountered in commerce in the form of fragments of variable size. It is very hard and very heavy. The cortical cellular tissue has a pronounced reddish-brown tint. For local purposes, the bark or the leaves are used directly by tanneries, and not submitted to extraction. There is now a growing export of mangrove bark, especially from Venezuela. The extraction of the tannin, for con- venience and economy in transportation, has not yet been as thor- oughly perfected as in the case of quebracho. There are, however, in Colombia, a few well-organized factories for this purpose. One factory at Cartagena, and another at Sinu, 80 miles from the coast, are each capable, of producing annually 3,000 metric tons of the solid extract. The process of manufacturing mangrove extract does not differ materially from that employed in producing quebracho extract. The bark from the younger steins of the tree surrenders its tannin most easily. Care must be taken to avoid the presence of salt, apt to be found on the bark, and originating in the salty marshes where the tree grows. The liquors, before concentration, are frequently de- colorized, or submitted to the bisulphite process, for the removal of undesirable substances. The solid product obtained by evaporation, in the Colombia factories, contains about 48 per cent of tannin. It has a vitreous luster and is very brittle. Extracts from mangrove bark of African origin contain from 60 to TO per cent of tannin. In tanning operations it is found that mangrove bark, or the ex- tract, alone gives an objectionable color to leather. They are, there- fore, blended ordinarily with other materials, such as myrobalans. In France, a favorite mixture is : Per cent. Mangrove bark 30 Hemlock bark 40 Oak bark 20 Mimosa bark 10 This yields an excellent grade of leather, with a fine color. On account of the limited amount of soluble nontannins in man- grove bark, the baths need to be but very slightly acidulated. The value of mangrove bark as a tanning agent for leather, and also as possessed of tinctorial properties, appears to have been recognized centuries ago in both hemispheres. Its use for coloring basket work was established far in the past. The first documentary evidence as to the employment of mangrove bark for the above purposes dates back to the early part of the sixteenth century, in San Domingo. The use of the bark in Europe began in 1804, when British tanners included it among their recognized sources of tannin. To-day it is regarded as one of the very cheapest forms of tannin now available, and its use is widespread. There seems to be every reason to expect that in the early future the enormous jungles of mangrove in Brazil, Venezuela, and Colombia will become most valuable assets. The importation into the United States of tanning extracts from Colombia, during the fiscal year ending June 30, 1914, amounted to TANNING MATERIALS OF LATIN AMERICA. 19 931,567 pounds, valued at $25,494, or 2.73 cents per pound. Pre- sumably these figures applied exclusively to the extract of mangrove bark. There has been a small import into the United States of mangrove bark from both Colombia and Venezuela. In the fiscal year 1914 Colombia furnished 8 long tons, valued at $80, or $10 per ton ; Vene- zuela supplied 87 tons, valued at $1,184, or $13.61 per ton. The im- port from Colombia reached 74 tons in 1912; and from Venezuela, 818 tons in 1910. The total import of mangrove bark into the United States, in 1914, was 7,689 long tons. In the fiscal year ending June 30, 1915, it was 13,040 tons. It attained 21,779 tons in 1912. Nearly all comes from the regions bordering the Indian Ocean. MINOR BARKS. There are a large number of other barks occurring in Latin America containing varying quantities of tannin, enough to render them at least of local value for the purpose of manufacturing leather. They may most conveniently be treated by grouping them under the countries where each one occurs most abundantly. BARKS OF PARAGUAY. A very complete exhibit of the barks occurring in Paraguay available for the tanner's use was made at the International Agri- cultural Exposition, held in 1910 at Buenos Aires. The catalogue of this special exhibit was very full and furnished data of value on each variety exhibited. A well-classified study of this exhibit was published by Dr. W. W. Stockberger in the Journal of the American Leather Chemists' Association, 1912, Volume VII, page 185. The following is a resume of the details given in the above sources, adopting Dr. Stockberger's systematic classification. The native names follow the botanical designation, in parentheses: FAMILY ANONACE^E. Rollinia sp. (aratikii gwazii). Tannin content, 4.2 per cent. The tree, well known for its fruit, is very common in the forests, and fre- quently grows quite tall. The thin bark, abounding in bast fibers, is easily removed. FAMILY APOCYNACEiE. Aspidosperma poly neuron Muell. (palo rosa). Tannin content, 2.6 per cent. A tall, stout tree yielding excellent timber. It is neither well known nor much used. It is of scattered occurrence in Parana, north of latitude 26°. A pink coloring matter in the wood deserves further investigation. The wood contains also a fair amount of tannin, and mention has been made of it in the preceding section. Aspidosperma quebracho bianco Schlecht (white quebracho). Tannin content, 4 per cent. This tree has also been mentioned in the preceding section. It is quite abundant in Argentina. The leaves contain 27 per cent of tannin and the wood 3 per cent. 20 TANNING MATERIALS OF LATIN AMERICA. FAMILY BIGNONIACEiE. Tec.oma ipe araliacea (?) (lapacho). Tannin content, 5 per cent. The tree is common and well known and one of those frequently used for timber. The bark is easily removed and has a whitish fracture. The epidermis and corky portion are cracked or fissured, and bast fibers are abundant. FAMILY C^ESALPINIACE^E. Apuleia praecox Mart, (yhvihra-pere). Tannin content, 10.7 per cent. The tree is stout, fairly common, and used for lumber. The pale yellow bark is smooth and not easily removed. Copaifera lansdorfii Desf. (kupaih). Tannin content, 16.6 per cent. It is accompanied by a certain amount of resinous matter. The tree grows to some size. It is a rare tree except in the forests along the course of the river Monda-ih. The bark is thick and of a ligneous structure. The fracture is whitish-red, and the corky layer readily breaks into small fragments. The fragrant balsam, known in commerce as balsam copaiba, was extracted from this tree at an early date by the Jesuit missionaries. FAMILY EUPHORBIACEJE. Alchornea triplinervia Muell. (tapia gwazu-ih). Tannin content, 11.7 per cent. The tree is abundant and grows to a good size. The bark is quite thick and without bast fibers. Its texture is granulose and fragile. It is easily removed, and has a reddish fracture. Croton succirubrum (?) (sangre de drago). Tannin content, 11.7 per cent. Resinous matter with a very penetrating odor is present. The tree is small. It is rare in the forests of the uplands but abun- dant along the rivers. The bark is smooth and easily removed. It is thin, quite fibrous, and has a white fracture. FAMILY FABACE/E. Salbergia sp. (yhsapih-ih). Tannin content, 5.8 per cent. The tree is stout and quite abundant. The bark is smooth and readily removed. It is slightly ligneous and has a blackish fracture. FAMILY GUTTIFERJE. Rheedia brasiliensis Planch & Trianan (pakuri). Tannin con- tent, 21.6 per cent. A small amount of resinous and coloring mat- ters is present. The tree bears fruit, is slender, and attains a height of 40 feet and more. The bark is smooth and easily removed. It is brittle and has a pale-red fracture. FAMILY LAURACEjE. Ocotea sp. (yhva-ika). Tannin content, 10.8 per cent. Large amounts of a mucilaginous substance are present, The tree is stout, tall, of frequent occurrence in the forests and often used for lum- ber. The bark contains few fibers and is grayish when freshly broken. TANNING MATERIALS OF LATIN AMERICA. 21 FAMILY MELIACE^S. Cabralea sp. (cancliarana). Tannin content, 5 per cent (in the young bark). The tree attains a good size, is exceedingly abun- dant, and is occasionally used for lumber. The mature bark is rather thick and somewhat fibrous. It is difficult to remove and has a whitish fracture. Cedrela tubiflora, (?) (cedro). Tannin content, 12.6 per cent. The tree is largely used for lumber and is common throughout Para- guay. The bark is quite thick, composed of tenuous and fibrous layers superposed. The corky portions are fissured. It is easily re- moved and has an irregular, reddish fracture. Two other allied species, containing about the same percentage of tannin in the bark, are also found in Paraguay. Guarea sp. (guare). Tannin content, 10.02 per cent. The tree is abundant and of medium size. The bark is easily removed, is lig- neous, and has a whitish fracture. TricMlia catigua A. Juss. (kaatigua puihta) . Tannin content, 20.5 per cent. It also contains a large amount of coloring matter. The tree is quite common. The smooth bark is easily removed in strips. It is readily broken and has a dark-orange fracture. The bark is used somewhat for tanning, but gives to the leather an undesirable harshness. TricMlia Meronymi Griseb. (kaatigua moroti). Tannin content, 23 per cent. A large amount of a yellow-rose coloring matter is pres- ent. The small tree is very common throughout Paraguay. The bark is smooth and readily removed in longitudinal strips. It is easily broken and has a whitish-red fracture. The bark is frequently used locally by tanners and is also employed to dye cotton fabrics. FAMILY MIMOSACEuE. Enterolobium twiboiiva Mart, (timbo). Tannin content, 22.3 per cent. A certain amount of resinous matter is present. The tree at- tains a large size, is very common, and is used for lumber. The bark is thick and has a corrugated epidermis and woody bast. The frac- ture of the young bark is white ; that of the mature bark is reddish. It is extensively used by local tanners. Inga affinis D. C. (inga gwazu). Tannin content, 25.8 per cent. The tree is stout and grows in profusion along the banks of creeks and rivers. The bark is smooth, easily removed from the tree, and deficient in bast fibers. It is brittle and has a whitish-red fracture. Mimosa, sp. (yukeri gwazii). Tannin content, 10.8 per cent. The tree possesses spiny branches and is quite abundant in certain locali- ties. The bark is thick and its fracture is dark yellow. The epider- mis is corrugated and quite ligneous. Peltopkorum dubium Taub. (yhvrihra puihta). Tannin content, 31.2 per cent. A very large amount of coloring matter is present. The tree is very common throughout Paraguay and grows at times to an unusually large size. The bark is thick and corrugated and very ligneous. It is easily detached from the trunk in long strips and has a red fracture. Piptademia rigicla Benth. (kurupaih-ra puihta). Tannin content, 28.2 per cent. A moderate amount of coloring matter is present. 22 TANNING MATERIALS OF LATIN AMERICA. The tree attains a great height and resembles the cedar. The bark is ligneous, the epidermis checked and corrugated. It is easily de- tached from the trunk and has a pale-rose fracture. A very similar species of common occurrence known as kurupaih- ra moroti, possesses the same tannin content. FAMILY MYRTACE.E. " Britoa fragrantissima" (?) (yhvaviro). Tannin content, 9.2 per cent. This small, fruit-bearing tree is found occasionally in great abundance. The bark is smooth, thin, and easily removed. It is somewhat fibrous and has a whitish fracture. Campomanesia guavird (?) (yhvavira). Tannin content, 11.6 per cent. The tree is fruit bearing and highly esteemed. It is well known and of common occurrence, frequently attaining great size. The. bark is thin and fibrous, difficult to remove, and has a whitish- yellow fracture. Eugenia bra-siUensis,~LsLm. (yhva-poroitih). Tannin content, 43.4 per cent. The wood contains 11.6 per cent and the leaves 16.6 per cent. There is a certain amount of resin and coloring matter present. The fruit-bearing tree is well known and very abundant. In certain low places it forms dense thickets. It attains a height of 33 feet and a diameter of 18 inches. The bark is smooth and closely ad- herent to the sapwood, especially when the flow of sap is scanty. It is without bast fibers. Externally it is white. The fracture has the color of hazel nuts. Eugenia michettii Lam. (nanga pirih gwazu). Tannin content, 28.5 per cent. But little other extractive matter is present. It is very abundant in low grounds, on the banks of small streams. It is apt to be associated with other species of the same genus, quite simi- lar in appearance, and all more or less tanniferous. The bark is thin and smooth, somewhat ligneous, with a whitish fracture. Eugenia pungens Berg, (yhva viyu). Tannin content, 10.8 per cent. This is a fruit-bearing tree, quite as well known and highly valued as the yhva-poroitih. It is larger in size, but of less frequent occurrence. The bark is thin, smooth, and very difficult to remove from the sapwood. The texture is fragile and the fracture has a cinnamon color. Eugenia sp. (regalito). Tannin content, 15.8 per cent. The tan- nin is exceptionally pure. The tree reaches a height of about 23 feet. It is less abundant than the allied members of the same genus. The bark is smooth, not very thick, and closely adherent to the sapwood. It is removable in small pieces. The fracture has the color of hazelnuts. Eugenia sp. (yhvajhay puihta, gwazii). Tannin content, 28.7 per cent. The tree is not abundant. It reaches 20 inches in diameter and 40 feet in height. The smooth, thin bark is easily removed. It is without bast fibers and has a whitish fracture. " Myrtus edulis" (?) (yhva mbopi). Tannin content, 21.8 per cent. The thin, smooth bark is somewhat difficult to remove. It has a whitish fracture. FAMILY PALM^E. Cocos romanzofjiana Cham, (pindo). Tannin content, 6.6 per cent. This palm tree is abundant in all the forests along the coast. It is TANNING MATERIALS OF LATIN AMERICA. 23 carelessly destroyed in order to obtain the leaves, which constitute an excellent forage for draft animals. The bark is often used for tan- ning the choicer grades of leather. FAMILY SAPINDACEiE. AUophyllus edulis Radlk. (kokii). Tannin content, 10 per cent. The tree is small and very common. The bark is thin, smooth, and difficult to remove. It is without bast fibers and has a yellowish- white fracture. Cupania uraguensis H. & A. (kambuata). Tannin content, 17.5 per cent. The tree is of moderate size and is frequently encountered in the forests along creeks and rivers. The bark is rather thick and closely adherent to the sapwood. It is removable in small pieces by hammering. It is ligneous and has a reddish fracture. Cupania vemalis Cambess. (yaguarataih). Tannin content, 15 per cent. The tree is small and fairly abundant. The bark is smooth, somewhat ligneous, and easily removed in large strips. The fracture is of a pale-rose color. Cupania sp. (ceclrillo). Tannin content, 15.8 per cent. The small tree is of scanty development, and is usually found in low places on the banks of creeks and rivers. The thin bark is somewhat adherent to the sapwood. It is fibrous and has a whitish fracture. The natives use it to tan fine skins. FAMILY SAPOTACE^E. Bumelia obtusifolia R. & S. (pihkasurembiu). Tannin content, 8.4 per cent. The tree is somewhat abundant and of moderate size. The smooth bark is easily removed. It is of a slightly ligneous structure. It will be noticed from the above that Paraguay is unusually rich in varieties of tanniferous barks. A number are of common occur- rence and the tannin content is unusually high. In the event, at a later date, of any very acute shortage in the world's supply of tan- ning materials, the forests of Paraguay alone should be able to con- tribute notably toward meeting the demands of international com- merce. BARKS OF ARGENTINA. As already mentioned, the bark of the true quebracho contains from 6 to 8 per cent of tannin. That of the white quebracho con- tains 4 per cent. About the same quantity is present in the bark of the red quebracho. Fair amounts of tannin are also present in the barks of other trees, already mentioned in connection with the tan- nin content of the heart wood, such as " tipa," " quebracho flojo," and varieties of Cedrela, all occurring in Argentina. To these may be added the two trees called popularly " cebil." They occur abundantly in several provinces of Argentina, notably in Salta and Jujuy, remote from quebracho forests, and are extensively used by the tanners of such sections. Piptademia cebil (Griseb.), red cebil, contains from 15 to 25 per cent of tannin in the bark and from 6 to 7 per cent in the leaves. Acacia cebil (Griseb.) contains 8 to 12 per cent of tannin in the bark and 7 to 8 per cent in the leaves. Mimosa farinosa (Griseb.). The bark contains 3.9 per cent of tannin. 24 tanning mateeials op latin America. BARKS OF BRAZIL. The tree known as Barbatimao (8 'try phnodendron Barb atimdo), occurs in abundance in the State of Minas Geraes, in the south of Brazil. The bark is stated to contain as much as 60 per cent of tannin. The price at present is $30 per metric ton, laid down in Sao Paulo or Rio de Janeiro. It makes an excellent leather. The angico tree is found also in Minas Geraes. The bark contains 28 per cent of a very light-colored tannin, highly valued by tanners. The price at the seaboard is the same as that of Barbatimao. Remoteness from industrial centers, and the high cost of transpor- tation have hampered any attempt to exploit these barks on an extensive scale. Eugenia jembos (Linn.) contains 12.4 per cent of tannin. The following is a list of the local names of barks found in Brazil, which have a very limited use in tanning: Arica, cannella, garabi, genubata, grannaniamba, guabari, hyrsonima, mimusops, monesia, pimento, santarita, schinus mollis, trumpet-wood, vanigra. BARKS of chile. Eucryphia cordifolia Cav. (ulmo). The tree occurs in abundance in Chile. The bark is largely used in local tanneries, and the extract is exported to some extent. This extract is of a dark-red color, and strongly resembles that obtained from mangrove bark. The United States purchases annually a small quantity of this extract, valued at about $8,000. Persea lingue (lingue). Enormous forests of this tree occur in southern Chile. The reddish-brown, soft bark contains from 20 to 24 per cent of a tannin, which is very easily extracted by water. It is of extended use locally for the production of the well-kno^n Val- divia leather. It has been used to some extent in Great Britain in tanning leather to serve for uppers. Laurus peumo. The bark of this tree also serves locally for mak- ing upper leather. BARKS OF PERU. The bark of the cascara tree is reported to be in extensive local use for tanning purposes. The alkaloids present in cinchona bark are largely in combination with quinotannic acid. No attempt has been made to utilize this con- stituent of Peruvian bark, as far as is known. BARKS OF VENEZUELA. Teeoma pentaphylla (roble Colorado). The bark of this tree con- tains 27 per cent of tannin, which is accompanied by a soluble, orange-red coloring matter. Teeoma leucoxylon (Mart.). This allied variety occurs chiefly in Guiana, where the bark is regularly employed in tanning. Weinma.nnia glabra. The bark has a limited use. The wood of the tree is highly valued for cabinet work. In addition to the above, the barks of the following Venezuelan trees are occasionally employed by tanners: Aguacate, botoncillo, coco palm, gateodo, simaruba, tamarindo, yagrumo, and urape. TANNING MATERIALS OP LATIN AMERICA. 25 BARKS OF MEXICO AND CENTRAL AMERICA. Oak bark is widely used for tanning throughout Mexico. The local varieties employed for this purpose are Quercus xalapensis (Encinos), Q. castanea, and Q. imbricaria (laurel oak). The last mentioned is also found in Guatemala and used there for tanning. Mimosa huamuchil. The bark of this variety of mimosa is widely used, especially in Oaxaca, for making suede leather. Pithelocolobium dulce (huamuchil 6 pinzan). The bark is used extensively in Jalisco and Morelos, in tanning saddle and harness leather. Lysaloma Candida (palo bianco). The bark is frequently used. Acacia malacophylla 6 mimosa sp. (timbre 6 timbre). This bark is employed largely to tan leather intended for bookbinding and for shoemakers. Mimosa biuncifera 6 acaci-a, sp. (una de gato) . In Michoacan, this is used in tanning black goatskins. Calliandra grandiflora (Raicilla). Employed in Morelos for making soft leathers. Bursera microphylla (Torote) and Entorobium cyclocarpum (Huincastle). The bark of both trees are of a very limited use in Mexico. The latter occurs also in Central America. The pods, as well as the bark, are said to be rich in tannin. Malpighia punici folia (nancite or manquitta). The tree is abun- dant in Nicaragua and in the West Indies. The bark contains from 20 to 30 per cent of a very light-colored tannin. BARKS OF GENERAL OCCURRENCE. Brysonima (Murici). Stryphnodendron barbatimum (Mort.) (tuga veca). The bark yields the amorphous Barbatimao tannic acid, an amorphous red powder. Both of the above are of scattered occurrence. BARKS OF THE WEST INDIAN ISLANDS. In the West Indian Islands several trees and vines occur, the barks of which contain tannin in industrial quantities. They may be briefly enumerated in order to complete the geographical survey. They are: Carapa guianensis (crab-wood) ; spondias lutea (hay plum) ; lecythis ollaria (kararalli) ; mora excelsa (mora) ; coccoloba uvifera (seaside grape), source of a Kino; nectandra (sirnahelli) ; bloodwood; baromalli or pump wood; cuyama. TANNINS FROM LEAVES. There are but few representatives in this class. Mention has already been made of the tannin present in the leaves of the white quebracho of Argentina, and of the extent to which the leaves of mangroves are employed in the tanneries of southern Brazil. The leaves of yhva-poroitih, Eugenia brasiliensis Lam., so abun- dant in Paraguay, contain, when air-dried, 16.6 per cent of tannin. They might advantageously be made the object of systematic an- nual exploitation, for the purpose of extracting the tanning principle. Guaiacum arborewn (molle-guayacan). The leaves are locally used for tanning in various tropical regions. The tree is closely allied to Guaiacum officinale, the well-known lignum-vita3. 26 TANNING MATERIALS OF LATIN AMERICA. Sumac, obtained in Mexico from the leaves of Rhus aromatica (Ait.) and Rhus copallina (Linn.) is the most important member of this category. The dry leaves contain about 13 per cent of tannin. Mention has already been made of the value of young fustic wood as a source of tannin. The leaves of this tree, Rhus cotinus, contain 17 per cent of tannin. They could also be profitably made the object of a systematic harvesting. These leaves bear easily sea transporta- tion. The different varieties of Rhus can advantageously be culti- vated, as is now the case in Italy. The tannin of sumac leaves is very similar to that present m myro- balans, but is somewhat paler in color. It is principally used in the production of light leathers. Sometimes warm sumac liquor is em- ployed to brighten the color of heavy tannages. As a rule, the Amer- ican varieties are less adapted for making white leather than the Sicilian sumac, on account of the presence of a certain amount of a dark coloring matter. It is to be noted that leather made by the use of sumac tannin is not very resistant to water. Aspidosperma quebracho bianco (Schlecht). This tree, the "white quebracho" of Argentina, has already been described as having a cer- tain amount of tannin in its wood, viz, 3 per cent. Its bark contains also 4 per cent. The leaves are, however, remarkably rich in tannin, the average amount present reaching 27 per cent. There is probably no other tree occurring abundantly in South America, the leaves of which possess as much value from the tanner's standpoint. No at- tempt appears to have been made to exploit this source of tannin, probably on account of the great abundance of the true quebracho, side by side with the white quebracho. In connection with the consideration of the bark of the mangrove, Rhizophora mangle (L.), attention has already been directed to the value of the leaves, as rich in tannin, and to their extensive use in the tanneries of southern Brazil. One of the most interesting occurrences of tannin in the leaves of South American flora is that connected with Paraguay tea, or "yerba de mate." The dried leaves and shoots of Ilex paraguensis (A. St. Hil.) are now used by over 30,000,000 inhabitants of South America to make an infusion which, as a beverage, replaces the tea or coffee of other regions. The tree is an evergreen, closely related to the holly, and grows abundantly in the mountain forests of Argentina, Paraguay, and southern Brazil. In height it ranges from 15 to 30 feet. The leaves are 4 to 6 inches long, lanceolate, with finely serrated margins. Infusion is made as in the case of Chinese tea. The so-called mate thus obtained is regarded as having valuable restorative qualities when taken after violent or prolonged physical exercise. It also possesses mildly aperient and diuretic properties. The caffeine pres- ent is not much in excess of 1 per cent, as compared with 3.5 to 4.5 per cent in teas of oriental origin. The physiological action of the tea, therefore, seems to be narcotic rather than stimulative. The tannin present in the leaves is also much less than in the case of ordinary tea leaves, being on an average about 1.5 per cent. This tannin is very peculiar in character, as it does not precipitate po- tassio-tartrate of antimony, and is totally without action on hides TANNING MATERIALS OF LATIN AMERICA. 27 and skins. Thus far this tannin remains more of a scientific curiosity than an article of commercial interest. TANNINS FROM ROOTS, BULBS, AND EXCRESCENCES. This category has also but a very few representatives in Latin America. There are no tannin-bearing excrescences similar to the nutgalls of Syria and China or the knoppern of Austria, and the number of roots is quite small. Fuchsia macrosieTrvma (churco). The root bark of this Chilean plant contains 25 per cent of a bright-red tannin. The bark is thin and brittle, and the tannin is easily extracted. It is used locally in Chile for making leather. Krameria trianria (Ruiz et Pa v.) (rhatany). This plant grows in abundance on the slopes of sandy mountains in Peru. The root is woody and branched. The cortex is fibrous, of a reddish-brown color, and is easily separated from the central, reddish-yellow, woody part. It has no smell, but is exceedingly astringent, without being bitter. In commerce it is usually found in the form of powder. The tannin content ranges from 38.3 to 42.6 per cent. It is much more abundant in the cortex than in the core. In a pure form it is a light yellow powder, quite soluble in water. The extraction by this means is very simple. A certain amount of the concentrated extract is exported. This is not used in tanning alone, but gener- ally as an addition to other liquors. Euiz, the botanist, was first led to investigate the nature of the root, having noted that it was used by women for rubbing the teeth and strengthening the gums. Rumex hymenosepalus (Torr.) (canaigre). This plant, known as the sour dock, or wild rhubarb, grows abundantly in those parts of Mexico, seldom visited by rain, where the average temperature is below 20° C. The plant grows to a height of about 3 feet. For cen- turies the natives of Mexico have used the air-dried, tuberous roots as a material for tanning hides. The name of sour cane (call na ger) was given the plant by the early missionaries, and this was gradually changed into canaigre. The roots weigh each from one-half pound up to 2 pounds. They live for five years in the soil. In practice they are gathered when 2 years old. In commerce canaigre is encountered in the form of red- dish disks or as a liquid extract. The plant is cultivated to some extent. It is, in fact, the only tanniferous plant in Latin America which can be profitably made the object of systematic culture. Tannin is found in all parts of the plant — stalk, leaves, flowers, seeds, and roots — -but chiefly in the last mentioned, which greatly re- semble dahlia roots in appearance. The percentage of tannin is exceedingly variable, depending upon the conditions of growth. An adverse environment favors a high percentage. On the contrary, in a rich, well-irrigated soil the percentage is low. During the annual period of growth the tannin content increases most rapidly at the beginning of summer, when the plant is dying back to the ground. At this period the astringent sap of the leaves retreats into the roots, thus contributing materially to heighten their percentage of tannin. Young roots 3 to 7 inches in length and nearly an inch in thickness contain 10 per cent of tannin. In roots that are 2 or 3 years old the amount present reaches 28 per cent. Trimble states that the 28 TANNING MATEEIALS OF LATIN AMERICA. pure tannin, which is much like that of mimosa bark, is a yellowish- white powder, readily soluble in water. On boiling with 2 per cent hydrochloric acid it yields an insoluble, red phlobophane, together with some protocatechuic acid. The tannin is accompanied by certain red and yellow coloring matters, which are extracted at the same time and distinctly affect the quality of canaigre-tanned leather. When a fresh root is cut the surface blackens on account of the dyestuff present. Canaigre root contains also from 5 to 8 per cent of starch, which must be re- moved by some suitable process in order to obtain good results. Hence, when an extract is prepared the temperature is maintained at from 30 to 50° C. Typical analyses of air-dried roots give : Per cent. Water 1 14. 7 Tannin 27.8-34.9 Nontannins 9. 4-18. 1 Ash l : 1.9-2.1 Insoluble 33.9 Carbohydrates 6. 8 To 100 parts of tannin come 23 parts of carbohydrates. The dried root and its extract have given very satisfactory results in the tanning of nearly every form of leather. The best results, as regards weight and firmness, are obtained in the finishing of harness leather and in making various light leathers. On account of the easy solubility of the tannin the whole operation of changing hides into leather proceeds with great rapidity. When used alone canaigre imparts to leather a distinctive orange color. TANNINS FROM FRUITS AND SEEDS. This group is more numerous than the two preceding groups, and some of its members are commercially of importance. DIVI-DIVI. Ccesalpinia coriaria (Willd.) (divi-divi, also libi-libi). The tannin is found in the seed pods. The tree grows to a height of 20 to 30 feet, and is indigenous in the West Indian Islands, Mexico, Ven- ezuela, and northern Brazil. Its pods are about 3 inches long and three-fourths inch broad. They are very thin and smooth. After drying they frequently resemble in shape the letter S. The color is a chestnut brown. The pods contain from 40 to 45 per cent of a tannin very similar to that present in valonia. This tannin is most abundant in the tis- sue of the pod, under the epidermis. There is little in the seeds. A typical analysis of the pods gives the following results : Per cent. Water 1 13. 5 Tannin 41. 5 Nontannins 18. Ash 1. 6 Insoluble 25. 4 Carbohydrates 8. 4 To 100 parts tannin come 20.2 parts carbohydrates. The tannin consists of a mixture of ellagitannin and gallotannin. It is accom- panied by a considerable amount of oily and mucilaginous matter. TANNING MATERIALS OF LATIN AMERICA. 29 Divi-clivi tannin is easily separated, in the form of a concentrated extract. This latter, as well as the ordinary solutions for tanning purposes, on account of the presence of the above-mentioned foreign matters, are liable to undergo sudden fermentation, especially during electrical storms. In the course of fermentation a deep-red coloring- matter is developed, which imparts to leather a dark stain. It is a problem not yet solved how this fermentation may be effectively avoided. The use of ordinary antiseptics has been of some assistance as a preventive. Divi-divi is an exceedingly cheap source of tannin. Its use is, however, not very extended. As a rule, it is mixed with various barks or their extracts. Leather made by the use of divi-divi extract alone is apt to be firm in dry weather but soft and spongy in damp weather. Ordinarily it is used as a substitute for gambier in the dressing of leather and in the rapid drum-tanning of light leathers. Sometimes its use in connection with leather is simply as a dyestuff. Divi-divi was first imported from Caracas, in 1769, by Spaniards. By 1848 it had come into widely extended use. The chief ports of shipments are Caracas and Maracaibo. The name is said to be derived from David Davis, the captain of the first ship to bring to Europe a cargo of the pods. The present consumption of divi-divi pods in the United States is not large. During the fiscal year ended June 30, 1914, 29,000 pounds were imported. The price per pound at the ports of shipment was 1.6 cents. The best known marks are Curacao, Maracaibo, and Monte Christo. Shipments are chiefly from Maracaibo, Parahiba, and Santo Domingo. The consumption of divi-divi in Germany is much more important. During 1913 the exportation from Colombia amounted to 951 metric tons and from Venezuela to 5,092 tons. The average value per metric ton at the ports of shipment was $4.76. Ccesalpinia tinctoria (H. B.K.; Berth.) (Bogota divi-divi). Ccesal- pinia sigyna (Eottl.) (tari). The pods from these varieties, as well as the so-called " false divi-divi," from other members of Cwsalpinia, differ but slightly from those of G. coriaria in appearance and tannin content, and are occasionally encountered in commerce. ALGAROBILLA. Ccesalpinia brevifolia (algarobilla; algarobito; algarobo). This plant occurs in sandy, dry regions of northern Chile, and also in Colombia. The pods, which contain three to six seeds, are cylindri- cal in form, sometimes curved, sometimes straight. These pods contain from 35 to 53 per cent of tannin, which is very readily extracted. This tannin appears to be a mixture of ellagitan- nin and gallotannin. It lies in semiresinous particles, adhering loosely to the somewhat open framework of the fiber. It is accom- panied by notable amounts of a yellow coloring matter. A typical analysis is the following: Per cent. Water *__ 13. 5 Tannin 43. Nontannins 20. Ash 1. 6 Insoluble 21.9 Carbohydrates 8. 2 LIBRARY OF CONGRESS 30 TANNING MATERIALS OF LATIN AMElx^. ° 16 ° 58 693 A To 100 parts tannin come 19 parts of carbohydrates. Concen- trated extracts of algarobilla tannin are easily prepared. They are, however, as in the case of divi-divi extract, although to a less degree, somewhat prone to undergo fermentation. When used in tanning, algarobilla gives much better weight and greater firmness than is the case with divi-divi. It is also less liable to cause discoloration of the leather. The best grades yield a light- colored liquor, which colors leather but slightly, imparting a light, reddish-yellow tint. After the extract has undergone fermentation it produces a leather of an exceedingly bright color. Experience has shown that it gives inferior results for sole leather, and that in gen- eral, when employed alone, the leather produced is apt to mold in the sheds. It is, therefore, in almost all cases, blended with other tanning materials, its exceptionally high tannin content serving to strengthen the weaker liquors. It is usually blended with myro- balans, divi-divi, quebracho extract, or hemlock extract. In prac- tically all cases it can replace catechu for blending. In consequence of its dyestuff content, algarobilla is occasionally used simply as a coloring material, especially on leather. Algarobilla is one of the very strongest tanning matters known. There are, however, some closely allied trees in Chile, which yield pods of an even higher tannin content. They are: Balsamocarpum brevifolium, 65 per cent of tannin; Prosopis pallida, 60 per cent; and Prosopis dulcis, 62 per cent. They are less abundant, but the pods are held locally in high esteem. Data on the commercial movement of algarobilla are lacking. Ccesalpmia cacolaco (cascalote). The tree is very abundant in several districts of Mexico, and the pods have formed from time immemorial the chief tanning material of the country. Toluca is the most important point of distribution of the product. Other cen- ters are the towns of Iguala, Morelia, Patzcuaro, Uruapan, and Zitacuaro. The tannin content is very high. Cascalote has an advantage over divi-divi, in containing a much lower percentage of mucilaginous substances. It gives good results in the manufacture of sole leather, and most other forms of leather, including morocco, glazed kid, box calf, enameled colt, pigskins, etc. The native method of tanning with the aid of cascalote is exceed- ing^ novel. Prepared hides are first placed for two days in a vat with a " weak " or " sweet " tan liquor, until the hides have uniformly taken the color. They are then removed and sewn up into bags, roughly reproducing the original shape of the animal. These are filled with a stronger tan liquor and a quantity of ground cascolote. The filled hides are then placed in rows on the pavement of the tannery court. The liquor slowly oozes out, and flows into a central pit, whence it is pumped from time to time to refill the hides. The strength of this liquor is retained by new additions of cascalote. The operation continues for about 15 days. For a part of the time the bags are piled upon each other, to the extent of six or eight tiers. The pressure on the lower tiers increases the rate at which the liquor oozes through the hides, and produces a remarkably good tannage. The liquor is finally withdrawn, the sewing ripped out, and the hides are placed in a lay-away vat for a week or longer. They are then ready for the finishing processes. Conservation Resources Lig-Free® Type I LIBRARY OF CONGRESS 016 058 693 P 9