Congo rubber

Congo rubber is a commercial rubber most notable for its forced cultivation, under conditions of great human suffering, in the Congo Free State. According to a 1905 article (shortly after the peak of Congo production):


 * Red Kasai and Congo rubbers are obtained from the same species of vines, namely, the Landolphia, Oicariensis Pal. Beauv., L. Gentilii De Wild and L. Droogmansiana De Wild, and the difference in color, which is the chief distinction, is probably due to the different climatic conditions in the two districts, and different modes of collecting and coagulating, and not to any inherent property of the latices. Landolphia Klainer also gives a reddish rubber when grown under the same conditions as the above mentioned species.  The red colour of the rubber appears to be accentuated more and more as the district in which the vine is cultivated is farther from the zone known as the Great Equatorial Forest.  In the south of the Congo territory, for instance, latitude 7S and 8S, the india-rubber collected is almost red. In the Upper Congo the latex from these varieties is very watery, whilst in the Kasai district it is thick.  In the former district it is coagulated by means of Bosanga, and in the latter it coagulates spontaneously in contact with air.

The bosanga method is described in the 1907 Journal of the African Society (as noted in a preface and postscript by the editor, a vastly more pleasant description than the outraged accounts of the Congo Reform Association a few years previous):


 * Makala is one of the great rubber centres of the Congo, and during my long stay at that post, I had excellent opportunities of studying the method of rubber-collection.


 * In different districts, this varies considerably. At Makala, each adult man has to bring in 5 kilos per month, and this he can collect in 40 working hours. Payment is at the rate of 30 centimes per kilo, of which about 10 per cent. is given to the chief and the balance to the actual gatherer.


 * The natives usually go out in couples—build a little shanty in the midst of the jungle and work in a circle round it. Climbing the rubber-bearing tree or vine, they slash the bark with two or three V-shaped cuts, one below the other, and then arrange a broad leaf underneath, so as to form a trough. This is to conduct the sap, which oozes out, about the consistency and colour of ideal milk, into a gourd, or preferably, a galley-pot, procured at the station. The rubber from trees and vines is mixed promiscuously, the natives preferring to tap the latter, as they say it flows more freely. In any case, they put some vine rubber into that from the trees, as it coagulates more rapidly.


 * Returned to their hut, the gatherers pour the sap into an earthenware pot containing water, place it on the fire and stir it with a stick which they call bosanga. In about ten minutes the rubber, owing to the acid in the bosanga, begins to collect round the stick, and soon a mass is formed. This is lifted out, placed on a big leaf and rinsed with clean cold water. Then, enveloped in leaves, it is kneaded for a minute or two with hands or feet, to press out the remaining moisture. It is now ready to be cut up into rough cubes, which are spread to dry on a little platform built over the fire. Here it remains for an hour or two, before it is packed in the loosely made baskets in which the native carries it to the station.


 * As the rubber-laden caravan of men, women and children, headed by the chief and the forest-guard, wind their way from their village into the post, discordant notes are blown on a trumpet made from an antelope-horn, and all chant a chorus. Long before the party reaches the post, this barbaric music, ever increasing in volume, heralds their approach to the official in charge, and he makes his preparations to receive the rubber.


 * He meets the laden caravan at the beam-scale of the station where the rough baskets are weighed and the price paid in cloth, salt, bells, soap, beads and suchlike coveted treasures. The payment over, off they all rush, like children out of school, yelling and shouting at the top of their voices.


 * The rubber is then spread on platforms under large sheds, until the women workers of the post have cut it into neat little cubes. This done, for three months it lies in layers on the platforms to dry and is turned once a fortnight, till all the moisture has evaporated. During this process it loses some 25 per cent. in weight.


 * Meanwhile very neatly plaited baskets are being prepared from rattan cane, into which the dry rubber is packed, till every basket weighs exactly 5 lbs. A tin label is attached to each, with the distinctive number and place of origin, and they are then laid out in long rows, ready for transport by porters, canoe, rail and steamer to Europe.

In modern times Landolphia owariensis Beauv., known as Congo rubber, eta, or abo, is primarily used for its fruits, but occasionally for rubber band production; it was a major source for rubber from nations including Sierra Leone, Ghana, and Nigeria in the early 1900s.