Crude rubber and compounding ingredients; a text-book of rubber manufacture

Front matter

Chap. -.L-.r Copyright No.

Shelf..i.2i.^

UNITED STATES OF AMERICA.

Preface

In its beginning, this volume was simply a brief, conveniently arranged portfolio of facts concerning the various ingredients that enter into rubber compounds. It was designed for the author's use alone. Certain rubber manufacturers, however, learning of its existence, and desiring copies of it, urged strongly that the matter be published and given to the trade as a whole in book form. The superiority of such a collection over the most comprehensive book of compounds doubtless will be apparent to the expert manufacturer, for this reason. When a manufacturer buys a set of compounds — and most of them are purchasable — he invariably acquires them not so much for use as for suggestion and comparison. The descriptions, therefore, of a great majority of the ingredients used in all lines of rubber compounding, and scores with which he may be unfamiliar, will be so suggestive to the practical man that new sets of compounds will be secured, each partaking of the individuality of the expert, and bearing the impress of the line of work done in the factory to which he is attached, and wholly free from the taint of imitation or counterfeiting, which is the bane of the purchased secret. It is felt that another point of supei lOrity over the mere compound book will be found in the fact that no private formulas are given, which might wound the feelings of the more conservative manufacturers.

The higher level of prices for crude rubber which has prevailed for some time past is drawing the attention of manufacturers to the pseudo gums — such, for instance, as Pontianak. A number of these are described in this volume, with the hope that, since their presence in the market depends largely upon the insistence with which rubber manufacturers demand them from importers or gatherers, many more may be made generally useful. Another line of endeavor that already has been fruitful of excellent result is in the production of rubber substitutes. It is hoped that the chapters upon this subject, covering some two hundred varieties, some excellent and others perhaps of little value, may prove of such service that, even if the ideal substitute

6 PREFACE.

does not materialize, the knowledge of the scope of the substitutes already known will be so increased that their intelligent use will be greatly amplified.

In the compilation of this book free use has been made of English, German, and French standard technical works as well as of technical journals, such as The India Rubber World, The India- Riibber and Gntta-Percha Trades Journal, the Gummi-Zeitung, The Journal of the Society of Chemical Industry, and others.

The author takes pleasure in acknowledging his indebtedness for helpful suggestions to skilled manufacturers and superintendents in both America and Europe, and to the following distinguished writers on rubber topics : P. G. W. Typke, F, C. S. ; G. S. Jenman, Government Botanist and Superintendent of the Botanic Gardens, Demerara ; William Thompson, F. R. S. E. ; H. Grimshaw, F. C S. ; W. Lascelles-Scott, F. R. M. S., M. S. C. I. ; Richard Gerner, M. E. ; Dr. C. Purcell Taylor, Thomas Bolas, F. C. S., F. L C. ; Professor D. E. Hughes, F. R. S. ; Messrs. Heinzerling and Pahl, Berlin; Granville H. Sharpe, F. C. S. ; Carl Otto "Weber, Ph. D. ; A. Camille, J. H. Hart, Superintendent Botanic Gardens of Trinidad; Dr. D. Morris, M. A., C. M. G., Commissioner of the Imperial Agricultural Department for the West Indies; the late Dr. Eugene F. A. Obach, F. I. C, F. C. S., M. E. E. E. ; Professor F. A. C. Perrine, D. Sc, and many others.

I also wish to express my appreciation of the valuable assistance given me on the chapters devoted to crude India-rubber and Gutta-percha, and the assistance in editing and revising other portions, by my associate editor on The India Rubber World, Mr. Hawthorne Hill.

Boston, June, 1899. HENRY C. PEARSON.

Chapter I

Grades of Crude Rubber, Sources of Supply, and Physical Characteristics ; Para, Central, African, and East Indian Gums ; Origin of Trade Names ; Botanical Details 9

CHAPTER 11.

Some Little Known Rubbers and Bastard or Pseudo Gums ; Possibility of Development of their Use in the Factory 24

Chapter I. Grades Of Crude Rubber, Sources Of Supply, And Physical

CHARACTERISTICS.

Caoutchouc or India-rubber is a product of a great variety of trees, vines, and shrubs, most of which grow in the torrid zone. Central America, South America, Africa, and India all furnish their quota, and while the gum that comes from these vast areas is all rubber, it differs widely in its characteristics, due in a measure to a variety of methods in gathering and coagulation, but more specifically in its chemical constituents. South America produces the best rubber in the world and the most of it. The Amazon valley, embracing hundreds of thousands of square miles of rubber forests in Brazil, Bolivia, and Peru, is the center of the industry, the product being exported from the city of Para, whence the name "Para rubber." Two or more species of the Hevea produce this rubber, the best known being the Hevea Brasiliensis. Peru also produces a rubber, lower in grade than Para, known as "Caucho." The Castilloa elastica, the rubber tree of Nicaragua and other Central American states, which is also found in Ecuador, Venezuela, Colombia, and Mexico, produces the rubber known as "Centrals." The Atlantic states of Brazil, south of Para, produce other rubber trees, from which come the grades known as "Mangabeira," "Pernambuco," and "Ceara." Africa ccmes next to South America in the amount of rubber produced, and in the interior of that continent, as in the Amazon country, there are great rubber forests as yet untouched. African rubber is inferior to that obtained from South America, but through improved processes in gathering and curing, the various sorts are delivered in much better condition year by year. African rubber is found on both the east and west coasts and throughout the great basin of the Congo river and also on the island of Madagascar.

The Landolphia, of which there are several species, is a giant vine or creeper from the milk of which most of the African rubbers come. Rubber from Lagos and from some other colonies in West Africa, however, is obtained from a tree known ■ as the lo GRADES OF CRUDE RUBBER.

Kickxia Africana. The East Indies to-day furnish but little rubber. The first rubber exported from that part of the world came from Assam. In time, however, Burma became a producer of a similar grade, known as "Rangoon" rubber. The principal source of rubber in that part of the w^orld is a tree known as the Ficus elastica. The islands of Java and Borneo and also Penang and other states in the Malaysian peninsula produce a certain amount of rubber.

Seaports, trading posts from which the first shipment is made, the name of a colony or country, or descriptive terms, as "thimbles," "buttons," "strips" — all or any of these may serve for names of different grades of crude rubber. A complete market report w^ould indicate that there are a great number of different qualities of rubber, many coming from the same source. This, however, is not wholly true. Take, for instance, the Para grades : years ago any rubber coming from Brazil was called Para rubber. Later it was divided into "fine," "medium," and "coarse." Then the rubber from the islands in the lower Amazon became known as "Islands rubber," while that coming from further up stream was known as "Upriver," and these, too, were divided into fine, medium, and coarse. Now a dozen or more local names are applied to rubber from different localities, tributary to the Para market. At the same time, most of these rubbers sell at the same figures, grade for grade, with the exception of coarse.

Something like this is true in the African rubber trade. For instance, a great number of local names are applied to the Congo rubber. The difference between "Equateur," "Kassai," and "Lopori" sorts may not be greater than between different lots from the same place. With a very few exceptions, the names which follow are those used commonly in the leading markets :

PARA RUBBER.

Rubber is classified atParaandManaos into three grades, designated by the Portugese words Una, entraiina, and sernamhy. These same grades in the United States are known as "fine," "medium," and "coarse," while in England they are classified as "fine," "entrafine," and "negroheads," the latter being divided to provide for a subgrade, "scrappy negroheads." The production is about 60

PARA RUBBER. ii

per cent, of fine, 13 per cent, of medium, and 27 per cent, of coarse.

Fine Para rubber comes in large bottles and, when cut, shows a surface closely marked with lines, corresponding to the number o{ layers of rubber milk added during the smoking process. These layers are easily separated and, when stretched, are very transparent. This rubber smells not unlike smoked bacon.

Medium or Entrafine resembles ''fine," but is not so well cured, curds and globules of milk not perfectly smoked being found between the layers.

Coarse or Sernamby is made up of the residue, scraped daily from the collecting vessels, or from milk which has curdled before it could be smoked and made into "fine."

Besides this general classification of Para rubber, other names are in use, derived from the localities of origin.

Islands rubber is that produced on the island of Marajo, some 17,500 square miles in extent, and other islands in its vicinity in the delta of the Amazon, together with that from other parts of the state of Para, except the Xingu, Tocantins, and Tapajos rivers, which might well be called lower Amazon grades. These islands in a recent year yielded over 12,000,000 pounds, or 63 per cent, of the total for the state of Para. The Islands "fine" and "medium" rubber is in the form of round or flat bottles, while the "coarse" or "sernamby" is in scraps massed into balls and round cakes, which gives the name "negroheads" to this grade in the English market.

Caviana rubber, named from the island that produces it, is the highest grade of Islands, and is to-day marketed as a distinct sort. It has a smooth close grain, and is much in demand for fine work.

Cameta rubber is so called from the port of that name, on the Tocantins river. It is noted for the superior quality of its "sernamby" grade, the "fine" being the same as from the islands, but rarely seen. This rubber comes in the form of little cups pressed into large "negroheads."

Upriver rubber includes the product of the country bordering the Amazon and its tributaries above Para, and that which comes from Peru and Bolivia through the large streams rising in those countries — such rivers are the Purus, Jurua, Javary, and

Madeira. This rubber for the most part is derived from the Hevea discolor and comes to market in biscuits varying greatiy in size and shape, a full average biscuit weighing about thirty pounds. The rubber tree on the islands is more frequently the Hevea Brasiliensis, but it is a mooted question whether the difference in the trees accounts for the difference in quality between Upriver and Islands rubber. "Upriver" rubber is marketed also under such local names as "Manaos," ''Madeira," "Bolivian," etc.

Itaituba rubber comes from the port of that name, at the head of steam navigation on the Tapajos river, which enters the Amazon at Santarem. Rubber from this river is distinguished for the rather gutty quality of the "fine" and "medium," and its stringy, dirty "sernamby."

XiNGU rubber from the Xingu river, is noted for the specially good cure of the "fine."

Manaos rubber is named from the city which is the capital of Amazonas, 1,200 miles up the Amazon river, and the center of the rubber trade of an immense district. Upriver rubber exported direct to foreign markets from this port is sometimes designated as "Manaos rubber."

Madeira rubber, named from a great river which joins the Amazon below Manaos, is of excellent quality and produced in large quantities. It has a finer and closer grain than any other upriver rubber except the Bolivian.

Bolivian rubber is floated down the Beni and other rivers in Bolivia to the Madeira, and thence to the Amazon. It meets innumerable detentions from cataracts in the upper Madeira, on account of which it becomes somewhat dried before reaching market. It has the further advantage of being cured by a better class of labor than is common in Brazil, of having a tougher fiber and of being cleaner than most upriver rubber, for which reasons it brings higher prices than any other.

MoLLENDO rubber comes from southern Bolivia, being transported by steamers across Lake Titicaca and by rail to Mollendo, a Peruvian port on the Pacific, and thence principally to England. It is prepared in biscuits and sheets and is marketed at a price between upriver and islands.

Angostura rubber comes down the Orinoco in Venezuela,

CENTRAL RUBBERS. 13

from Cuidad Bolivar, which town formerly was known as Angostura. It is of the same grades as the Para sorts. Some of the same class of rubber finds its way into Brazil, at Manaos, where its identity is lost.

Orinoco rubber is the same as "Angostura.^' Matto Grosso rubber is from the state of that name in the southwest of Brazil, and reaches the market partly through tributaries of the Amazon and partly through the Parana, which discharges into the river Plate. It comes in "fine," "medium," and "coarse," but principally the latter, little of it reaching the market at present,

Caucho is a distinct sort of rubber, inferior to that from Para, collected along the Peruvian rivers tributary to the Amazon and particularly along the Javary. It is not cured by smoking, but by the admixture with the milk of lime, potash, or soap. The physical characteristics of Caucho in the main are the same as in the Central American rubbers. It is known also as "Peruvian rubber" or "Peruvian caucho." It is exported from IquitoS; Manaos, and Para, and included in the general total of rubber exports from the Amazon country. It comes to market in three forms — Ball, Strip, and Sheet (or Slabs) — ranging in value in the order named.

CENTRAL RUBBERS.

Central American rubber, or "Centrals," includes that which is produced in all the states north of the Amazon valley, up to and including southern Mexico. It forms a distinctive class, being the product of a tree not found elsewhere. The consumption of Centrals in the United States was larger once than of Para rubber, but the yield has declined gradually to small proportions. This rubber is in good demand for certain uses, ranking in price below coarse Para. It has not the toughness or strength of fine Para, and possesses less elasticity. Centrals are classed usually as "sheet" and "scrap," besides which the terms "strip," "slab," "ball," and "sausage" are used. Greytown being a common shipping-point for Centrals, there is much confusion, one sort often getting substituted for another. Most of the yield of Costa Rica is exported through Nicaragua. The treatment of Centrals generally consists in heating the sap and stirring in a strong concoction of the mik of bindweed, the product being "sheet" rubber. The rubber drippings which adhere to the bark of the tapped trees are peeled off when dry and called '"scrap." The trade names below apply to the locality of origin, rather than indicating distinctions in quality.

Nicaragua rubber includes more than the product of that republic. The real Nicaragua rubber is drier as a rule than other grades of Centrals. Nicaragua sheet comes to market in a less clean condition than formerly, and the scrap now brings a better price.

Greytown scrap is the best grade of Nicaragua rubber.

Guatemala rubber is inferior and unequal in quality. The best is whitish in color, and the lower grades black with a tarry appearance. It is said to be sometimes adulterated with cheap molasses. In curing, the rubber-gatherers pour the sap upon mats to dry, afterwards pulling off the product in sheets, pressing them together for shipment.

Guayaquil strip^ from Ecuador, is imported in two grades — good and ordinary. Like the Guatemala rubber, the best has a whitish appearance. The inferior sort is porous and filled with a fetid black liquid, which carries an almost indelible stain.

Esmeralda rubber, which also comes from Ecuador, is classed as a Strip and Sausage, the two grades coming to market in about equal quantities.

Colombian is a pressed strip rubber, dark in color, sometimes showing white when cut. It is graded "No. i" and "No. 2." Some of the rubber from Colombia bears local designations, besides varying in quality. These include:

Cartagena, a strip rubber, dark and tough, graded "No. i" and "No. 2," selling at less than "Colombian." It comes also in thin sheets, rough or "chewed" in appearance, and tarry or sticky. The production has decreased very much of late.

Panama rubber, like that from Nicaragua, embraces a wide range of quality. The Pacific mail steamers bring together at Panama rubber from numerous ports, and confusion of grades is a result. What is marketed as "Panama" comes in "sheet" and "strip."

Tumaco comes in "sheet," "slab/' and "scrap," from the Pacific coast of Colombia. Very little of it is received.

Mexican rubber is of fair quality, but is received in constantly decreasing quantities. The grades, listed in the order of their selling value, are Ball, Strip (or Scrap), and Slab.

Tuxpam strip comes from the Mexican port of that name. Very little of it is received, and that not of uniform quality.

Honduras strip is of a quality similar to the Mexican, but is little produced.

West Indian rubber has a good reputation for quality. It is not produced on the islands, but comes from Venezuela and Central America, and is simply a general trade name used in England.

The grades which follow, though not entitled geographically to be included as "Centrals," are in fact so classed, on account of their quality.

Mangabeira rubber is so called from the local name of the tree producing it, in the Atlantic states of Brazil, south of Para. It is an alum-cured rubber and comes in sheets, which resemble slices of liver and are of a tawny red color. The thin sheet sells for more than the thick, as it is dryer and better cured. Occasionally it comes in the form of balls. It is exported from Pernambuco, Bahia, Natal, and other points on the coast.

Pernambuco is another name for Mangabeira rubber, derived from the principal state and port from which it is shipped.

Ceara rubber comes from a tree particularly abundant in the Brazilian state of Ceara and is marketed principally in England. The sap exudes from the tree and coagulates in the form of "tears" which are gathered in scraps and balls. There are three grades, the lowest of which is dirty and difficult to use. Ceara rubber is deficient in elasticity and is hard to vulcanize. It is very dry and free from stickiness.

AFRICAN RUBBER.

African rubbers, though comparatively late in becoming known, are produced now in quantities second only to the supply from the Amazon. As a class they are more adhesive and less elastic than Para rubbers, ranking with or below Para negroheads. They often contain a liberal percentage of impurities, and for a iC GRADES OF CRUDE RUBBER.

long time their disagreeable odor and intractable nature hindered their introduction. But advancing prices for Para grades and fear of their coming scarcity led manufacturers to experiment with African rubbers, until many uses were found for them. The result has been a temporary check in the upward tendency in price of the Para grades, although there are many purposes for which Africans never have been considered as competing with them. At the same time, the possibilities in the way of utilizing African sorts have not been exhausted, each year bringing out new uses.

The African rubbers are obtained from giant creepers, of which there are a dozen species on the continent and in the island of Madagascar, and also from several trees, the most important one of which abounds on the Gold Coast, in Lagos, and some other West Coast colonies. The adulteration of African rubbers is not uncommon, being due to the dishonesty, not only of the native gatherers, but doubtless also of some foreign traders on the coasts. But in several of the English and Belgian colonies stringent laws have been passed to prevent such adulterations. On the Gold Coast the lumps of rubber brought to market by the natives were formerly cut into strips or buttons by machinery, before being exported. To-day this work is done in England, the rubber then being known as "Liverpool pressed." It has been urged by some importers of Lagos rubber that wilful adulteration by the natives is rare. Rubber has been worked in Lagos for only about four years, so that many of the workers there are yet inexperienced and lacking in skill. Even in the Gold Coast Colony, where the industry began ten years earlier, a certain percentage of the rubber is spoiled in gathering.

The milk of the Landolphia vines, the chief rubber producers of Africa, coagulates on exposure to the air, though in some localities use is made of various astringents, boiling in water, and other methods to assist in preparing rubber. Even where these methods are used, a residue of the rubber sap is left to dry on the bark and in the earth, and is gathered in strings or scraps. The only treatment in some other places is the smearing of the sap upon the bare bodies of the natives, where it dries speedily in the sun, and is easily peeled off.

Ball is the classification of a larsfe share of the African rubbers, which comes in every size from three or four inches in diameter down to half an inch or less. "Small ball" of the several kinds differs from the "large ball" in size, and is also dryer and affords a smaller degree of shrinkage.

Thimbles. — The natives, after gathering this rubber, cut it into cubes, about an inch square or less. Thimbles contain bark and sand, but very little moisture.

Nuts. — Rubber thimbles from Ambriz are quoted sometimes in European markets as "Ambriz nuts."

Lump rubber comes in large pieces, varying in size and of irregular shapes. When packed in casks the pieces often become massed together in transit. It is from the best of the lump rubber that the most desirable buttons and strips are made.

Flake comes in lumps, livers, and soft irregular masses, and is valuable in the factory chiefly for frictions and for softening compounds.

Paste is the same as "Flake." The Accra flake and Niger paste, which are the same in quality, are at the foot of the list, in respect to prices, the Niger being the cleaner.

Strips are lump rubber that is sliced and pressed by machinery before it is offered to the trade.

Buttons is a name applied to rubber similarly treated as in making strips, except that it is cut into small pieces, whereas strips have been marketed in every length up to ten feet.

Biscuits is another name for "Buttons."

Oysters is another name for "Buttons" or "Biscuits."

Tongues. — Some rubber formerly came to market in long, narrow, tongue-shaped pieces. The same grades are now more frequently seen in the shape of large balls.

Niggers are of various sorts and from different sources. These rubbers are ball-like in some cases, having the appearance of masses of stringy rubber pressed together between the hands and wound into compact masses.

Twist rubber is not unlike "Niggers" in quality, but shows less shrinkage and differs in preparation and appearance. The string or strip-like pieces are wrapped about each other in order to give a twisted look to the balls.

The list of rubber grades which follows is based upon a geoi8 GRADES OF CRUDE RUBBER.

graphical arrangement, beginning with the upper west coast of Africa :

GAMBIA.

Gambia Niggers (No. i, No. 2, No. 3). — These are classified according to cleanliness, No. i and No. 2 being fairly clean, and No. 3 containing considerable soil.

Bathurst. — Same as Gambia.

SIERRA LEONE.

Sierra Leone Twists (No. i. No. 2, and rejections). — This is white and amber in color, of low shrinkage, and has bark and grit in it, but little moisture.

Niggers (No. i. No. 2, No. 3) are quite moist. No. 2 and No. 3 contain considerable soil.

Cake. — Fairly clean, but wet. It is both red and white, the former bringing the better price.

Manoh Twists. — This comes in the shape of tightly wound cords of rubber and works soft. In color it is black or white, the black being the best.

LIBERIA.

Liherian. — This is graded as Lump, Hard Flake, and Soft. It cuts yellow, is very wet, and is often a soft pasty rubber.

ASSINEE.

What is known as Assinee is graded as follows: Assinee- Silky, Grand Bassam, Attoahoa, Lahou, Bayin, Half Jack. It is like Old Calabar, only it comes in chunks three inches square, is wet, and cuts yellow. These names are chiefly used in the English market.

GOLD COAST COLONY.

Gold Coast. — This is chiefly lump from which Strips and Buttons are made. There are also Biscuits and Niggers (hard and soft). The Flake is wet and has a bad smell, but otherwise is quite clean.

Accra. — The Accra lump furnishes Strips and Buttons and is graded "prime," "seconds,'' and "thirds." The lower grades are Flake and Paste.

Cape Coast. — This is another lump from which Strips and Buttons are manufactured and has for lower grades Flake and Soft.

Salt Pond. — This Lump is also used in Strips and Buttons, the lowest grade being Flake.

Addah Niggers (graded as No. i and No. 2) is very similar to Sierra Leone, but generally in smaller balls. It is not an Accra rubber, nor are Quittah Niggers or Axini. As a matter of fact, the grades from these different ports differ little if any, and are sold most frequently under the head of "Accra" rubber, from the name of the principal town in the colony.

TOGOLAND.

Lomi (or Lome) Ball. — The best grade of this is a clean, firm rubber and is fairly dry. The lower grades are rarely seen.

LAGOS.

Lagos. — This Lump is also turned into Buttons and Strips, while soft inferior lumps are sold without manufacturing, as low grades. It is very easily distinguished from Accra by its odor.

NIGER RIVER PROTECTORATE.

Niger. — The chief grade is Paste, which has an acid smell and is a low grade pasty rubber, wet but clean.

Old Calabar. — It is graded as Blue, Lump, and Niggers and is very bad smelling. The best lump is undoubtedly used for strips and buttons.

Benin Ball. — Is generally dirty and has a rotten, woody smell.

CAMEROONS (OR KAMERUN).

Cameroons. — The Ball is graded as large, mixed, and small ; the Clusters, which contain some fifty balls, as No. i and No. 2 ; and the Knucklj^ ball, which is a small dry ball. This rubber has a fairly strong smell.

Batanga Ball ("B," "E'^). — Same as Cameroons, Batanga being the name of a river and country in the Cameroons.

FRENCH CONGO.

French Congo rubber is very similar to Cameroon, but the balls are larger,

Gaboon is the best known flake and has for additional grades : Lump, Large "O" Ball, and Small "O" Ball. The Flake is free from dirt and is soft.

Mayumba is both Ball and Flake. Another grade known as Mixed is a combination of the two and is sold as second quality.

Loango. — Ball.

These are names of rubber stations on the coast. The natives boil rubber milk, adding the juices of vines, and, while the rubber is hardening, wind it into balls, weighing from one-fifth pound to three pounds. The best rubber is not boiled, the milk drying on the wrists of the natives, as they tap the rubber vines. At the coast the balls are cut, to detect any cheating, and washed and packed in casks for export.

CONGO FREE STATE.

Congo rubber comes in the shape of Buttons, Balls (No. i and No. 2), Red Thimbles, and Black Thimbles. The Ball is similar to Cameroons, but tougher. The Dutch Congo Ball is the same as the Congo Ball, but is known as the best grade of that rubber. There is also the Congo (Kassai), Black Twist (graded as fine, mixed, and secondary), and Red Twist. The Strips are among the toughest of African rubbers and are dry, with a woody smell.

From the Lower Congo comes also the Luvituku, which is a Red Ball rubber, and from the Upper Congo, the following:

Upper Congo. — Ball, Red Ball, Twists, and Strips, all of which is good tough rubber.

Uelle. — Strips, usually heated and fermented and bad smelling; Cakes, wet, but clean.

Sankuni. — Ball, very similar to Congo Ball.

Lake Leopold. — Graded as Sausage and Ball. It does not dififer from the foregoing enough to warrant special description.

Equateur. — In the form of balls (small and mixed). It is dark, dry, and clean, but contains some fermented rubber, which smells badly.

Lopori. — Graded as Ball (large and small). Strips, and Cakes. Some of the balls are fine and clean, while others contain fermented milk. Lopori also comes as Sausage.

Bangui. — Comes in the form of strips and is a firm, tough rubber.

Bussira. — Ball ; a trifle softer than Lopori, but usually of excellent quality and dry. In use it develops a strong smell.