# Popular Science Monthly/Volume 85/November 1914/Rubber: Wild, Plantation and Synthetic

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* RUBBER: WILD, PLANTATION AND SYNTHETIC
By Dr. JOHN WADDELL
SCHOOL OF MINING, QUEEN'S UNIVERSITY
AN industry can not be wholly uninteresting which involves the consumption yearly of about $250,000,000 worth of raw material in the production of goods worth $750,000,000 which has grown to nearly double its size in seven years, which involves the cultivation of three quarters of a million acres or more of land, worth about $130 an acre, but half of which has during a boom been capitalized at double its value, an industry whose center will be speedily shifted from the banks of the Amazon, half way round the world, to Ceylon and the Malay State?, unless very heroic measures are taken to prevent it, among which heroic measures the importation of 50,000 Chinese coolies into the Amazon valley has been suggested.
Such is the rubber industry. When it is added that the price, which for a number of years had been a little above a dollar a pound, went up during 1910 to over three dollars and last September fell as low as fifty cents; and that in connection with the rubber trade there have been some of the most sensational stories of inhumanity and barbarity in the Congo district and on the upper Amazon, it will be seen that the economist and the social reformer must be specially interested.
There are, too, features of interest for the botanist, since rubber is got from plants and its function in the plant is obscure. Moreover, there are notable peculiarities in its extraction which offer opportunities for further research. The chemist is interested not only from the point of view of the conversion of the raw product into a material suitable for the many purposes to which it is applied, but also from the fact that he sees here one more opportunity to replace the work of nature and to do in a small laboratory covering only a few acres what now requires thousands of square miles.
A book appeared in Spain early in the seventeenth century (1601-15) describing the voyages of the Castillians, from 1492-1554, in which a game played by the natives of Hayti with balls made from the gum of a tree was mentioned. About the same time Juan de Torquemada described a rubber tree of Mexico, the Castilloa elastica, and stated that the Indians used the rubber for medicinal purposes and that the Spaniard used it for waterproofing coats. Rubber trees of various kinds were soon discovered in Brazil, French Guiana, Madagascar and other places.
Chemists attempted to find industrial uses for the product of the rubber tree, and it may be added that the search in the future is likely ​to be more vigorous than it has ever been in the past. The difficulty of discovering a good solvent baffled chemists for a time, but in 1761 Herissant and Macquer used oil of turpentine and said that ether might also be employed. The name rubber seems to date from Priestley's discovery in 1770 of its power to erase pencil marks, the name caoutchouc being apparently a modification of the Indian name cahucha. In Priestley's time rubber could not be considered a plentiful article of commerce, its price being twenty shillings an ounce.
Though patents for the use of rubber as waterproofing had been taken out as early as 1791, Macintosh in 1823 seems to have been the first to make the industry a commercial success and the firm then started in Glasgow and afterwards removed to Manchester remains to this day as one of the most important in the rubber industry.
The next important step was taken by Hancock in England and Goodyear in America about 1840, the date being a little inexact because the process seems to have been in use before being patented. This was the addition of sulphur to rubber by which it is made capable of standing the hottest summer temperature without becoming sticky or losing its elasticity.
It was not till about 1886 that a process was discovered for depriving rubber of the smell which restricted its use for waterproofing. The rubber industry received an impetus when pneumatic tires came into use for bicycles, and the employment of rubber as an insulator in electric installations also increased the demand, but the dominating factor in the consumption of rubber has of late years been the automobile business. The very sudden demand in 1910 caused a tremendous rise in prices, and whereas during a portion of 1909 the price in London was 2s. 9d. in 1910 it reached 12s. 6d.
The growth of the rubber industry is indicated by the following figures. Import of crude rubber into Great Britain was in
| 1830 | 23 | tons |
| 1850 | 381 | " |
| 1870 | 7,656 | " |
| 1910 | 43,848 | " |
The rubber plant grown in houses for ornamental purposes is usually Ficus elastica, which is native mainly to southern Asia. This is not the plant chiefly used for the production of rubber. Four different orders of plants provide commercial rubber and there are eleven genera belonging to these given in Thorpe's "Dictionary of Applied Chemistry." By far the most important is Hevea brasiliensis which provides the "fine Para" rubber of South America the standard of rubber in the trade. To the same order, Euphorbiaceae, belongs Manihot Glaziovii also found in a small section of Brazil. It produces the Ceara rubber of commerce. ​Another interesting source of rubber is the genus Landolphia, of which there are several species noteworthy as being creepers. This genus provides most of the Congo rubber and belongs to the order Apocynaceae. Ficus elastica spoken of above is one of the genera of the order Urticaceae of which another genus is Castilloa also already mentioned as found in Mexico and one of the very first plants to attract attention as a rubber producer.
Rubber, though found to a slight extent as a solid deposit in the woody fiber of certain species, is almost entirely obtained from the latex of the rubber-bearing plants. The latex is a fluid usually more or less viscous which is carried in vessels, the laticiferous vessels, lying in the inner bark just a little outside of the cells which carry the sap. The caoutchouc itself is in globules of microscopic or sub-microscopic size, being from 1/50,000 inch to 1/6,000 inch in diameter, and forms an emulsion with the suspending liquid. A familiar example of latex is the exudation of the milkweed. The function of latex in the plant itself is unknown. It may be an excretion, it may be intended for the preservation of the tree from attack by fungus or insects or other enemy. The process of raw rubber manufacture consists in the collection of the latex and the coagulation from the serum of the emulsified particles. In tapping the trees the essential thing is to cut deep enough into the bark to sever the laticiferous vessels, but not to cut into the cambium, the living layer of cells from which both the wood and the bark of the tree are produced. In the Amazon Valley this is usually done by a small axe, the incisions being of a V shape, the first being made at a height of about six or seven feet. Later incisions are made at intervals of about two inches below the previous ones, till the base of the tree is reached. Then tappings are begun on the other side of the tree in the same order as before. The latex is collected in a small cup fixed to the tree by moist clay and is removed from time to time. Five pounds of latex is considered a large amount from one tree during the season. The latex is gathered from the cups into a pail and is cured by the smoke of a fire rich in tarry and acid matter. A long wooden rod has rubber latex poured over it and the thin layer which sticks to the rod is dried in the smoke. Over the sheet thus formed is poured more latex, which is also dried in the smoke. Thus layer after layer is produced till a ball weighing from twenty to one hundred pounds is obtained. Thus is made raw fine Para rubber. Some of the latex coagulates on the tree, forming a scrap rubber which is collected and compressed into irregular masses called "negroheads."
It is not my purpose to describe all the processes through which raw rubber passes before it appears in the shape of golf balls or automobile tires or in any of the many forms in which it comes into commerce, but a very brief outline may be given. First, the raw rubber is cut into ​small pieces, steeped in warm water and run through washing rolls, after which it is dried. Rubber thus obtained is mainly a hydrocarbon of the empirical formula C$_5$H$_8$, that is, it contains sixty parts by weight of carbon to eight of hydrogen. There is a small amount of resin, a very little protein and somewhat less than one per cent, of inorganic matter which forms an ash when the rubber is burned.
Freshly coagulated rubber has a spongy or reticular structure, due to the way in which the particles come together. This shows even in dried rubber and the particles can still be seen in globular form after solution, but films made by the evaporation of the solvent from the solution have apparently lost the reticular character. Rubber on being heated becomes sticky and if cooled to near the freezing point of water (about 40° Fahr.) it becomes hard and loses its elasticity. Stretched rubber has the very peculiar property of contracting on being heated. This curious property was predicted from theoretical considerations and was later confirmed by experiment. A suitable way to carry out the experiment is to stretch a rubber tube to nearly double its length by means of a heavy weight and then to pass steam through the tube. A tube a couple of feet in length will under these circumstances contract several inches.
Pine rubber softens too readily with rise of temperature and hardens before the temperature has fallen much below normal; the range of temperature through which it retains its properties of toughness and elasticity is too limited, but by the addition of sulphur the range of temperature can be very much extended. Rubber can be made to take up sulphur in various ways, the process being called "vulcanization." One method is by heating with sulphur, another is by treatment in the cold with a mixture of chloride of sulphur and carbon bisulphide. The properties of vulcanized rubber vary with the amount of sulphur, soft rubbers contain 3-4 per cent., while hard rubber, or ebonite, contains 20-30 per cent. The sulphur seems to be combined in some form, at least partially with the rubber. No matter how much sulphur may be mixed with the rubber or what the temperature or length of time, the maximum of combined sulphur is about thirty-two per cent.
The main source of rubber supply, almost up to the present, has been the wild-growing trees and vines. In 1006 about 400 tons (approximately one per cent, of the whole) were obtained from plantations, by 1909-10 the amount had risen to about five per cent.: now plantation rubber has almost overtaken that derived from uncultivated plants. Java produced 73 tons in 1910 and 491 tons in 1911, while, during the first three months of 1912, the Malay States produced 3,810 tons, and during the corresponding three months of 1913 the amount was 5,625 tons, or over a half more. The rapid increase is due to the fact that each year more and more of the trees are reaching the productive age.
​In 1876, some seeds of Hevea brasiliensis were sent from Brazil to Kew Gardens, and some young plants from these seeds were shipped the same year to Ceylon, where they were planted in low land and the grove then started is now historic, for it was the beginning of the later industry. Up till 1899 there were only about 750 acres of rubber plantation in Ceylon and these were apparently not intended for commercial purposes. In 1899 the first company in the Malay States was formed and it declared a dividend of 75 per cent, in 1908, and owing to the high prices or rubber in 1909 the dividend was 250 per cent.
The large amount of rubber required for automobile tires naturally stimulated the planting of rubber areas. According to figures given in a U. S. Consular Report in January, 1913, the acreage in Ceylon in 1912 was 220,000 and in the Malay States 430,000, while in other countries over 100,000 acres were under cultivation. Figures given later in the year by The Economist were higher. The larger part of this area is not yet productive, and some of it will not yield for five or six years.
The source of cultivated rubber is almost entirely Hevea brasiliensis, which seems to be adapted to wide differences of conditions. In Ceylon, though first planted in low land, it grows on hills with large boulders, in the Malay district it thrives on flat land with hardly a stone. On the Malay hills, where heavy rains would carry away the young trees, contour drains are constructed. The genus Castilloa does not grow so readily in the East; it takes longer to reach the producing stage and it does not produce so much rubber when it has attained its proper growth. It has, however, been largely planted in its original home, Mexico. Manihot-Glaziovii is planted in dry regions, where Hevea does not flourish.
Hevea is not fit for tapping till it is seven years old. As the seven or eight feet nearest the bottom of the trunk are richest in latex, the object in cultivation is to produce short trunks of large circumference. With this end in view, the trees are planted far apart, at a distance of about twenty feet from each other, giving approximately a hundred trees to the acre. They are induced to fork at a height of about ten feet, and it is said that the best arrangement is a tripartite forking of the main trunk, each branch in turn forming three subordinate branches. In places where there are high winds, however, this style of forking may provide so large a surface that the trees may be blown over.
There are various methods of tapping, the most satisfactory apparently being full or half "herring bone." A vertical groove is made in the bark of the tree from the base to a height of five or six feet. Then parallel incisions are made from this vertical groove in an upward slanting direction, in the case of the half-herring bone, on one side, and in the case of the full herring bone, on both sides. So important is it to cut through the laticiferous vessels without injuring the cambium layer and so difficult is it to accomplish this kind of incision, that dozens of ​different knives have been invented for the purpose. The half-herring bone method is considered the better as being less severe on the tree.
A very curious phenomenon was observed in the early experiments on tapping. It was found that if a second incision was made in the bark of Hevea, near one cut a couple of days previously, there was a greater flow of latex than if the second incision were made at a distance, say, on the other side of the tree. More than that, the latex flowed more freely than on the first incision. In a particular experiment on four trees, tappings were made at intervals of five days, and the volume of latex increased from 61 c.c. at the first tapping to 449 c.c. at the fourteenth, when the series was ended. In view of the fact that the latex from later tappings is thinner than that from the first, another series of experiments was made on ten trees which were tapped every day for a fortnight and the rubber content of each tapping determined. This rose from 641/4 oz. on the first day to 333/4 oz. on the fourteenth. Within limits a thin latex is the most satisfactory, the latex from the first incision often being of little use because it coagulates before reaching the proper receptacle and so gets mixed with the bark of the tree and other foreign.matter. Sometimes drip pans are fastened to the tree above the incisions, and water dropping upon tire incisions prevents the latex drying on the tree.
The peculiar action of Hevea owing to which subsequent tappings near the previous incisions produce a greater flow of latex is called "wound response," and no other rubber-bearing plants show wound response in anything like the degree shown by Hevea; in fact, it may be doubted whether the phenomenon occurs in the other genera at all. As compared with Hevea, Castilloa gives a greater flow of latex on the first incision, some five or six times as much. But if, after a couple of days, a further incision is made near the former one, little or no latex flows from it, while, as we have seen, there is in the case of Hevea a greater supply than before, roughly about twice as much, which persists through subsequent tappings. Accordingly, in tapping trees a very thin paring (about one twentieth of an inch) is removed each day or each alternate day. As the first incisions are made about a foot apart, it takes some two hundred and forty parings before the bark is all removed from this part of the tree, and as by the half-herring-bone system only about a quarter of the tree is tapped it takes about four years to remove all the bark and by that time operations can be begun again on the new bark that has formed in the meantime.
The arrangement of laticiferous vessels in Castilloa is different from that in Hevea; in the former the vessels all connect in a somewhat similar manner to that of veins and arteries in the body. Hence, when the vessels are cut, there is likely to be a drain from a large area. In Hevea the tubes arise from a breaking down of cell walls which occur from time to time and so the latex does not flow out so freely at first. ​Possibly, the increased flow when the second incision is made near the first is because latex has flowed to the wound in order to repair it.
Though Hevea seems to be in general the best rubber-producing tree, there is a little doubt whether it should be everywhere introduced; for instance, in Africa, where another species is native. African labor is less intelligent than that in the Malay States and the African natives can not tap the trees so successfully. The native trees and vines are usually cut down.
Moreover, experiments should be made with plantations of from three to five thousand trees before a decisive judgment is given, for it is possible that in large plantations diseases might rise and spread which have not appeared in small plantations. In very large estates, protective belts of other trees either of the original forest or of another genus of planted rubber should be made use of to prevent spread of diseases.
While, as stated above, in the Amazon valley five pounds of latex containing approximately two pounds of caoutchouc is considered a large yield, on the plantations trees ten years old are expected to yield three or four pounds of rubber. During 1908 nine thousand trees in the Cicely estate, one of the older Malay companies, gave an average of six pounds per tree, though the trees were between five and ten years old. In the Perah State there were eight trees seventeen years old, of an average girth of 55 inches, which yielded 281/2 pounds of rubber each. From the economic point of view the yield per acre is of more importance than the yield per tree. Six-year-old trees will yield about a hundred pounds per acre, while ten-year-old trees will yield three or four times as much.
In the East, rubber is coagulated from the latex by acetic acid. Smaller quantities of other acids would serve the same purpose, but an excess prevents coagulation, while with acetic acid the quantity may vary within fairly wide limits. When coagulation is brought about by acetic acid either pains must be taken to dry the rubber very thoroughly or some antiseptic must be put in. The method of smoking carried out in the Amazon district provides both acetic acid and the antiseptic fumes of creosote. Coagulation could be brought about by simple drying, but in this case the rubber is apt to become moldy and putrid. The precise cause of coagulation by acid is not certain. It has been ascribed to the small amount of protein in the latex, but, on the other hand, it is claimed that if the protein is removed the rubber can still be coagulated. The rubber produced has a composition something like the following: 94 per cent, caoutchouc, 3 per cent, resin, 2.5 per cent, protein, and 0.5 per cent, each of moisture and ash. One should perhaps add that what is usually called protein may not really be that substance, but some other which contains nitrogen.
The competition between Amazon hard Para rubber, which is so far the standard, and plantation rubber is keen. The latter is the purer, but ​the conditions for vulcanizing and otherwise treating Para rubber are better known and rubber manufacturers will probably agree with the opinion expressed to me by one of them that plantation rubber is not so easily worked. Para rubber is said to be harder and "nervier" in the mixing rolls and is more consistent in quality. What causes the difference is unknown; whether the immaturity of the plantation trees, or the method of curing or some other factors. The difference is exhibited not only in the ways indicated, but also by the action of some chemical reagents. In a series of experiments, the part of Para rubber soluble in petroleum ether was in one sample 51 per cent., in another 57 per cent., while of Ceylon biscuit 58 per cent, and 68 per cent, were soluble, and of Malayan crepe 72 per cent, and 86 per cent. The part dissolved from the Para rubber was much more viscous than that from the other kinds.
The price of plantation rubber in the London market is lower than that of Para rubber, but this is probably due, at least partly, to the method of sale by auction. According to The Economist, during the first eight months of 1913, Para averaged 3s. 101/4d. while plantation rubber averaged 3s. 51/4d. and, curiously enough, when plantation rubber dropped in September to 2s. a pound, Para was 3s. 7d.
Though up to the present plantation rubber is not equal in quality to the best Para rubber, it will be remembered that a considerable quantity of the rubber from the Amazon district itself is not of the highest grade. One quarter or more is of inferior quality. The price in general has dropped till it leaves little margin above the cost of production. While the export from the Amazon district has increased little, if any, since 1909, being in the neighborhood of 42,000 tons, plantation rubber, which in 1909 was 4,000, amounted in 1912 to 30,000 tons. The total rubber consumption in 1912 was about 108,000 tons, part of it being wild rubber from Mexico and various places in Africa, part being old rubber reclaimed. In the season 1912-13, according to the IT. S. Consular Reports, the Amazon district exported 2,200 tons more than in the previous season, but the same reports predicted a decrease in the season 1913-14 and, according to the Journal of Commerce, during July, August and September, the first three months of the 1913-14 season, the export was 7,161 tons as compared with 8,553 tons of the year before. The statement is made in the Consular Reports that this year for the first time other countries will produce a greater amount of plantation rubber than the Amazon Valley of wild rubber.
Mr. Akers, a British rubber expert, estimates that in 1916 plantations could yield 173,000 tons and in 1919, about 300,000 tons. He also estimates that if rubber falls to two shillings a pound 150,000 tons or perhaps 200,000 tons might be consumed for the present uses, but unless new uses not now apparent are discovered the supply will much exceed the demand.
​At present the cost of production of Para rubber is 72 cents, including the export tax, which amounts to 24 cents. This high cost is partly due to the cost of living, partly to difficult transportation, partly to scarce labor and inefficient methods of gathering the rubber. Mr. Akers recommends the importation of 50,000 Chinese coolies, the employment of a number of Malayan planters to instruct the collectors in the best methods of tapping, and the abolition or, at all events, reduction of the export tax. The Brazilian government has given a large sum of money to improve navigation on the Amazon and to provide premiums for the construction of rubber factories and refineries, engaging to buy from these refineries all the rubber required for the army and navy. They doubtless feel chary about reducing the export tax, as it is a great, if not even the greatest, source of revenue.
The future of the rubber industry causes anxiety not only to the Amazon district and those interested in it, but to the thousands of stockholders in eastern plantations. The great demand for rubber for automobile tires caused a boom and, according to The Economist, £40,000,000 was invested in boom prices "whose only justification is the few years of grace before the supply surpasses the demand." On September 20, last, the same paper remarks:
The collapse of the rubber boom is one cause for the lack of business in the Stock Exchange. Hundreds of thousands of pounds poured into the plantation rubber industry by the British public are represented by huge stocks of certificates, the depreciation on which, reckoned from the price at which the public got them, will serve as a painful lesson till the next boom, from whatever quarter it may spring up, comes along.
A large meeting of the leading people in the rubber world was held in London on October 23, and stocks went up just before the meeting, only to fall when it was learned that no solution of the difficulty could be found. The cost of bringing an estate into bearing condition is between twenty and thirty pounds an acre, and The Economist estimates over seven hundred thousand acres in the East capitalized at from £54 to £76 an acre.
It will not pay to produce rubber to sell in the world's markets at two shillings a pound, unless the cost of production can be reduced. In some very favored estates, in Ceylon, the cost is only sixpence a pound and, when all the trees are yielding, the average cost may be 8d, though in 1911 it was Is. 4d. Mr. Akers considers that in Java the cost will not go below Is. 2d. for several years. In Ceylon labor is more easily obtainable than in the Malay States and Java. In the Malay States a good deal of the labor is done by coolies from southern India along with some Chinese. An economic question arising here is the relative value of indentured and unindentured labor.
The artificial production of rubber is not yet a matter of commercial ​interest. Dr. Gerlach, of Hanover, a practical manufacturer, thinks it may be twenty years before artificial, or, as it is sometimes called, synthetic rubber can compete with the natural. He points to the fact that it took at least as long a time for synthetic indigo to reach the commercial stage after it had been first produced in the laboratory. Millions of dollars were expended in the investigations by one firm alone. But as we have had the romance of the alizarine industry, by which a product of coal tar replaced the extract of the madder root and ended its cultivation in France, and the romance of the indigo industry which has so largely affected the growth of the indigo plant in India, so we may have the romance of the synthetic rubber industry, but many a long and weary investigation must be carried on, many patents will be abandoned and much money will be spent, apparently in vain, for no process can be considered commercial unless it can produce rubber not only more cheaply than it can now be obtained from the plantations, but more cheaply than there is any likelihood of its ever being produced from natural sources. Probably twenty cents a pound should be considered the maximum cost of a commercial process for synthetic rubber.
Rubber was found to yield on heating the substance isoprene among others. This substance has the same percentage composition as rubber, but its molecular structure is considered to be simpler and to be represented by the formula
${\begin{aligned}CH_{2}=&C-CH=CH_{2}\\&\,|\\C&H_{3}\end{aligned}}$
Isoprene was accidentally found to change into rubber apparently upon long standing, and efforts were made to produce rubber from isoprene at will. It was found that by heating at a high temperature with acetic acid in closed tubes the change takes place and later a small amount of sodium was found to produce a similar effect at a lower temperature.
The problem of synthetic rubber is then two-fold: first, to get cheap isoprene; second, to convert isoprene cheaply into rubber. The most natural source of isoprene seems to be oil of turpentine, which has the same percentage composition, but it has not proved satisfactory and its formation from isoamyl alcohol gives greater promise. Isoamyl alcohol is one constituent in fusel oil, whose presence in raw spirits renders them so injurious. It is obtained to a small extent in the ordinary fermentation of potatoes and other starchy substances. Professor Fernbach, of the Pasteur Institute, has discovered a method of fermenting starch which, instead of yielding a large amount of ordinary alcohol and a small amount of fusel oil, produces fusel oil with practically no ordinary alcohol. This fusel oil, however, instead of having a large quantity of isoamyl alcohol consists chiefly of butyl alcohol, from which butadiene, ​${\ce {CH2 = CH - CH = CH2}}$, can be made in just the same way as isoprene from isoamyl alcohol. Butadiene is the next lower homologue of isoprene, and when it is treated with sodium it produces a substance very like rubber which is called nor-caoutchouc. It is said that its quality is even superior to that of ordinary rubber. As there are a number of alcohols homologous to butyl and isoamyl alcohol, a number of substances similar to isoprene and butadiene can be made from them, and from these by the action of sodium a series of rubbers. It is said that the rubber produced by the action of acetic acid on isoprene is identical with natural rubber, and that the rubber made by the action of sodium is slightly different in its chemical reactions. It may be that all natural rubbers are not identical and that the difference between Para rubber and plantation rubber may depend upon some slight differences in the caoutchouc itself and that what the chemist does with extreme difficulty when he changes starch into rubber, nature does with ease, and, as the chemist may get slightly different products by pursuing different methods, so nature may get different products under different circumstances. It was said at the beginning of this paper that rubber has the empirical formula ${\ce {C5H8}}$. It seems that the formula is more correctly written ${\ce {C10H16}}$ and that the name 1.5 dimethyl cyclooctadiene 1.5 represents the structure of Para rubber, while the rubber produced by the action of sodium on isoprene is
1.5 dimethyl cyclooctadiene 1.3 or 1.5 dimethyl cyclooctadiene 1.7
Dr. Duisberg, of Elberfeld, stated in his address to the Congress of Applied Chemistry at New York in 1912 that he had for some time used tires of artificial rubber on an automobile. The German Emperor has also received a present of similar tires. The rubber can be made, but it is still far too expensive to compete with natural rubber.
Closely connected with the history of the rubber industry are the Congo atrocities. Congo rubber is not so good for most purposes and commands a lower price, though, being softer, it is said to be better as a filling for driving belts and for other uses. It is obtained from Landolphia vines, which are not usually tapped, but cut off, the latex being extracted all at once. This fact may be partly responsible for the atrocities, since, the more accessible sources of supply having been depleted, the natives have been obliged to go farther and farther in order to obtain the rubber demanded of them.
In the sixties and seventies of the last century, central Africa became known to Europe, and the commercial interests of the various nations led to what is termed the "Scramble for Africa." Stanley's discovery of the Upper Congo induced King Leopold to form the "International African Association" and he sent several investigating expeditions at ​his own expense, commanded for the most part by Englishmen and Germans and represented to the world as being entirely for scientific purposes. Later Leopold proposed forming the association into a state and obtained the sympathy and support of the British Chambers of Commerce by promising perfect freedom of trade, and of the protestant missionary societies of England and America, of the aborigines' protection association, and of the philanthropic world in general by his protestations of the highest type of philanthropy.
Several years before that time, Sir Robert Morier suggested to Lord Beaconsfield to recognize the claims of Portugal to the southern bank of the Congo, while the northern bank was to become British. Lord Beaconsfield, however, did not favor this plan, and when, in 1875, the consul Lieutenant Cameron proclaimed, on his own initiative, the taking possession of the basin of the Congo, his act was repudiated by Lord Carnarvon. Portugal and England had historic claims on the country, and the two governments made an agreement in 1883 by which Portugal was to gain the basin of the Congo on both sides for a certain limited distance from the mouth, engaging to give freedom of trade to the world and religious freedom to all inhabitants of the country. The treaty was denounced by the British Chambers of Commerce and the British philanthropic world. The British government was accused of betraying national interests, and in Portugal the Portuguese government was accused of the same thing. France was ready to step in and take the district, in which case foreign trade would be handicapped. King Leopold seized the opportunity, and Stanley, acting on his behalf, renewed the advances made before to England. The English government was now more ready to listen to the proposal, but, being anxious to secure freedom of trade and protection of the natives, fell in with the invitation of Bismarck to an international conference at Berlin. This conference was held from November 25, 1884, to February 26, 1885, and guaranteed the formation of the Congo association into a state. The representatives of the different powers may be almost said to have wept for joy at having found so disinterested and philanthropic a ruler for the state as King Leopold promised to be. On August 1, Leopold notified the powers that the International African Association would henceforth be known as the Congo Free State.
King Leopold began to form an army, and by 1889 two thousand regulars had been recruited and were armed with modern rifles, and the proposal for the next year was to raise eight thousand more. The King's officials were given a bonus for each recruit obtained, and these recruits were gathered by armed raids on the villages.
In 1891 a regulation was issued forbidding the natives to sell ivory and rubber (the main products of the country) to European merchants, and the officials were given a bonus for the amount of rubber supplied ​by them, the rubber becoming the property of the state and the bonus being the greater the less the cost of the rubber. A similar bonus was given on ivory and gum copal. This was a direct stimulus towards extortion on the part of the officials. Villages were taxed for a certain amount of rubber, and if it was not forthcoming punishments of all kinds were inflicted, a common one being the cutting off of hands, another, the carrying off of the women as hostages.
Such a feeling was aroused in Europe by reports from missionaries and others of the atrocities, that King Leopold was compelled to appoint a commission of enquiry, which reported in 1905 or early 1906. This report tells that the native peoples are "exhausted" through the demand made upon them for head-carriage in the transport of government material and that they are threatened with partial destruction. Captain Baccari, envoy of the King of Italy, traveled through that region and says, "we have all the ghastly scenes of the slave trade, the collar, the lash, and the pressgang." A lieutenant in the Italian army who spent three years in the Congo Free State and served in Leopold's African army writes:
The caravan road between Kasongo and Tanganyika is strewn with corpses of carriers, exactly as in the time of the Arab slave trade. The carriers, weakened, ill, insufficiently fed, fall literally by hundreds; and, in the evening, when there happens to be a little wind, the odor of bodies in decomposition is everywhere noticeable, to such an extent, indeed, that the Italian officiers have given it a name "Manyema perfume."
The commission reports that the direct causes of the miseries of the natives are the requisitions in rubber and the requisitions in staple food supplies "everywhere on the Congo, and, notwithstanding certain appearances to the contrary, the native gathers india rubber only under the influence of direct or indirect force." It indicates what is meant by force, namely, indiscriminate massacre, settlement of soldiers in rubberproducing villages, uncontrolled and unhampered in the execution of their instructions, taking of hostages, imprisonment of women and children, flogging, illegal fines and punishments and so on. The condition of the rubber gatherer is described:
In the majority of cases he must, every fortnight, go one or two days' journey and. sometimes more, to reach the place in the forest where he can find in fair abundance the rubber vine. There the gatherer passes some days in a miserable existence. He must construct an improvised shelter which can not obviously replace his hut; he has not the food to which he is accustomed; he is deprived of his wife, exposed to the inclemencies of the weather and to the attacks of wild beasts. He must take his harvest to the station of the government or the company, and it is only after that that he returns to his village, where he can barely reside two or three days before a new demand is made upon him.
This is taken from the report of King Leopold's own commission, which naturally does not overstate the case. I could easily have quoted ​a much more lurid description of the facts. I shall merely add one sentence from Professor Cattier's famous volume upon the Congo which was discussed in the Belgian House of Representatives, along with the Report of the Commission. He says:
The impositions in rubber and foodstuffs which weigh upon more than half the territory, that is to say, over an area three or four times as large as France, subject the natives to a well-nigh-continuous slavery, a slavery more severe than that imposed by the Arabs.
In 1908 the Congo was made over by King Leopold to Belgium, and the transfer was recognized by practically all the Great Powers, except Britain, who withheld her sanction till 1913. On May 29, 1913, Sir Edward Grey announced to the House of Commons the intention of the British Government to recognize the annexation of the Congo by Belgium and said that they were now fully satisfied that the condition of affairs had completely changed. While it shocks us that the atrocities should have gone on so long, it is probably true that at no previous stage in the world's history would the condition of uncivilized savages have been so much a matter of concern to the millions who had no personal interest in them.
Atrocities have been reported in the Putumayo district of Peru on the upper Amazon, some of the newspapers describing them as worse than those on the Congo. This is probably an exaggeration, but there have doubtless been very great cruelties inflicted upon the Indians there. But as the matter has been the subject of investigation not only by religious missions, but by a commission of the Peruvian government, as well as by a British government commissioner and by a select committee appointed by the House of Commons, it is to be hoped that the inhumanity is now at an end.