254 



THE AGEICULTUKAL NEWS. 



AuiJUsT S, 1908. 



RUBBER IN SOUTHERN NIGERIA. 



The report on the Foresfc Adminstration of South- 

 ern Nigeria, for the year 190(i, has just come to hand, 

 and the particulars givni in reference to the collection, 

 preparation, and export of rubber show that this indus- 

 try is of great importance in the Protectorate. The 

 rubber is all obtained froni wild forest trees and creeping 

 vines, the chief sources being Fwntutnia elastica, 

 Landfilplila oiruriensis, and Clltandra eladica. 



The total output of rubber for "1906 aiuouuted to .3,43-t, 

 279 lb., valdecl locally at £307,077, as compared with 

 3,109,707 lb. of rubber, valued at £249,043, wliieh wa.^ 

 shipped ill the previous year. These figures iuclude the exports 

 of Northern Nigeria. 



Experience of the past few yearsi with trees of Funfumia 

 clitstini indicates that tliis plant jjossesses much less recupera- 

 tivi' piiwer after tapping than is shown by Para rubber trees. 

 I'lie most satisfactory methods for tapping Funtumia 

 tree.s are stated to be the simple ' halfdieiring-lione ", or the 

 simple 'V method, ai)]ilied very lightly. It is reported 

 that the Assistant Conservator of Forests carried out some 

 taj5pii)g experiments with the sjiiral method, and procured 

 a larger yield of latex than has so far been obtained by other 

 .S3'stems, but it has yf t to be a.scertained whether such treat- 

 ment has a depressing effect on the growth of the trees. 

 Although the total quantity of Funtumia rubber cx[jorted 

 from the Protectorate is very considerable, the actual yield 

 olitained from each tree is small, and varies from 2 oz. tn 

 3 oz. per tapping. 



hrv l''nntuniia rublier contains, rui the average, i>0 per 

 cent, by weight of pure caoutchouc, and tlir latex yield>4 

 about CO per cent, by weight, of dry rulilx r. In ilic prepara- 

 tion of the rubber in Southern Nigeria, the latex is, in 

 general, either allowed t(i coagulate sjiontancousl}-. by expos- 

 ing it to the air in shallow vessels, after dilution with water. 

 or it is coagulated l:y heat, applied directly to the latex, 

 or indirectly, by placing a vessel filled with the fluid in boil- 

 ing water. Alcohol and acetic acid are also sometimes used 

 as coagulating agents. 



After coagulation has occurred, the lum[>s of rubber are 

 ■washed, and pressed into the form of biscuits. If then pro]!- 

 erly dried in an atmosphere containing smoke, the l>iscuits 

 acquire a rich lirown colour, and the best qualities conunand 

 a price not nnich less than Para on the London market. It 

 is .stated tliatsanq)les of funtumia rubber ])repared by officers 

 of the forest Department were valued in Furo|)e at 4.<. M. 

 per It), at a time when fine Para ruliber was si'lling at .">•<. 2/1. 

 per lb. 



The vine /yiiiii/of/ih/n (jiraneiixis is of rather slow grnwlli, 

 but the latex contains a very large |>roportion of rublu'r, and 

 over 90 per cent, of the dry rubber consists of piu'e caoutchouc. 

 The annual yield from a large \ine varies from J, to 

 •J lb. of rubber. The latex of Landolpliia is frequently 

 coagulated by treatment with hot smoke, while the methods 

 inentioneil above are al.so used. Landf)l])hia rubber fetches 

 a price of about 2d. per lb. less than tli;it nbtained for 

 l''unluniia rubber. 



I'dl'orts arc being made by officers r -i ted uilli llie 



Forest Administration to inti-oduce more .skdled ami careful 

 jnethods of preparing the rubber, and as improved methods of 

 treatment become general, higher jaices will no doubt be 

 obtained. 



Para and Castilloa rnlibci' trees have also been obtaincil 

 and planted at the ISotaidc Stations bi.tli of the \\'estcrn and of 



the Central Province. On account of unsuitable climatic condi- 

 tions, the trees are not fiourishing in the Western Province, 

 while in the Central Province tlie Castilloa trees are reported 

 tfi have sufi'ered severely fr(jm attack liy a lioring insect. 

 Para trees, however, have done well at the P.otanic (iardens 

 of tlie Central Pro\ince. 



Mr. J. H. Hart reports {Wrst Iiuluin Bulletiv, 

 Vol. N'lII, p. 198) that Fanfumia elastica is being 

 largely planted in Trinidad. During IDOfi many 

 thousands of seeds were told, and plants to the number 

 of 50,000 were distributed from the Botanic Station. 

 Mr. Hart also mentions that rubber can be obtained 

 from this tree at an earlier age than in the case of any 

 other rubber- vieldingt/ree. 



IMPROVED PROCESS FOR THE 



PREPARATION OP RUBBER. 



A patent tor an improved process in tlie manu- 

 facture of rubber, and referring jjrimarily to rubber 

 obtained from Castilloa latex, has l.itelv been taken 

 out by Dr. Pehr Olsson-Setifer (in partnership with 

 niiiiilnr;. Particulars of the in vention, together with 

 dlii>iiaiions of apparatus suitable for carrying out the 

 jjriparation of rubber by this improved process, appear 

 in the liuiut-ruhher Jinirnal of May 4 last. The 

 following is taken from the description given: — 



Aecoiding to this invention the latex — which is first 

 treated with formalin or other preservative to ]ii event firema- 

 ture coagulation— is poured into the tank and diluted 

 preferably with about an equal volume of water. It is then 

 strained in a centrifugal or other apiiaratus to separate the 

 latex from the bark, sand and other mechanical iinpuiitic.s, 

 these being intercepted by a canvas or other screen. The 

 strained material is then pas.seil to a coagulating tank, which 

 is conveniently steam-heateii and. providoil with a worm or 

 other conveyor. In this tank the latex is raised to the 

 re(piired temperature, which should not exceed 115° F., 

 a small quantity of a suitable rubber preservative, such, for 

 in.stance, as an alcoholic solution of creo.sote, .salicyclic acid 

 or carbolic acid, being add^'il. In some instances, as, for 

 exau'.ple, when tiie latex is obtained from old trees, it is 

 desirable at this stage to intermix with the material a coagu- 

 lant, such, for example, as acetic acid, tannic acid, forndc acid 

 or cream of tartar, in sufficient (piantity to obtain a neutral 

 reaetii>n nf the latex. 



frum the coagulating tank the piartially cdagulated 

 latex is passed into " creaming ' or .settling vats or tank.s^ 

 where it is allowed to stand, in oider that the latex may 

 .separate from the motherdiqnor owing to the ditt'erence in 

 their .specific gravities. This separation may take place in 

 about two hours and the liuitherdiipmi- or ihe main portion of 

 it is then drawn ort' from. the bottom of the tanks and tlie 

 latex washed Ijy a stream of water \vhich is passed upward 

 from the bottom of the tank, whence it is received in any 

 suitable recc|ptacle. 



The fi'cshly coagulated mbber is then eonveyed on a slid- 

 ing table to washing rolls, which may be of the ordinary 

 diamond-cut type, and rolled into corrugated strip.s. These 

 strips arc dried under vacnum luitil, .say, only (> or 7 per 

 cent, of the moisture remains, when they are folde<I and 

 |iressed, preferably in a press which ]>rc.sscs the rubber into 

 lilocks. Whilst still under ))ressure the niliber is snbnuttcd 

 to a further drying process,' and is then ready for packing 

 and shipment. 



