and Magazine of the Ceylon Agricultural Society. 



801 



cansos which cannot easily bo overcome, such 

 as weather, age of trees being tapped, and the 

 bringing of new trees into bearing, all of which 

 affect the colour and clearness of the dried 

 rubber. The discoloration is due to oxidation 

 of soluble organic bodies allied to tannin in the 

 latex water, by means of an oxidising enzyme, 

 and is intensified by a warm temperature and 

 exposure to the air. Thorough washing of the 

 freshly coagulated caoutchouc will remove much 

 of the soluble matter with the enzyme, but it 

 is difficult or impossible to remove it all, and 

 other means have to be adopted to prevent the 

 darkening on drying which almost invariably 

 occurs. This is done by destroying the enzyme 

 by means of heat before oxidisation occurs, 

 with the result that the rubber dries of a clear 

 pale yellow colour, and of perfect uniformity 

 from day to day. The 



HEATING CAN BE DONE IN DIFFERENT WAYS 



before or after coagulation: — 



1st. By passing eteam into the bulked latex 

 until the temperature reaches 80° or 167° F, 

 and maintaining this temperature for 15 minutes 

 or longer, according to the thickness of the 

 rubber. • 



2nd. By immersing the biscuits or sheets 

 etc., in water of the temperature for some min- 

 utes immediately after passing through the 

 above rolling machine; then re-rolling to the re- 

 quisite thinness, and immersing again for a 

 shorter time to ensure destruction of the 

 enzyme. 



3rd. Hot water can be employed in the wash- 

 ing machine, and if necessary, steam heated 

 rollers as well. 



Heating while coagulating most nearly re- 

 sembles the method of making hard para, but the 

 other method gives excellent results. 



To insure the best product cleanliness in all 

 stages of collection and manufacture is abso- 

 lutely essential, and if the loss in the value 

 from want of simple precautions in prepar- 

 ation was more fully realised on the estates, 

 much greater care would be exercised. Many 

 samples of excellent rubber appear on the Lon- 

 don market, but from want of uniformity, and 

 perhaps the presence of some slight impurity, 

 they do not realise, by some pence per lb., the 

 value they otherwise would. 



Rubber made by this process, has already been 

 sold on the market, and realised a premium of 

 up to about 4d. per lb., over ordinary good bis- 

 cuits which indicates that the process can be 

 successfully applied on the estate. It still re- 

 mains to be proved whether the rubber is 

 stronger than that manufactured by the ordinary 

 method, and Messrs Gow, Wilson & Stanton, 

 Ltd., are now having it tested by manfacturers to 

 determine this point, but as the process re- 

 sembles in some points the manufacture of tine 

 hard Para, there is reason to expect some im- 

 provement in the physical properties in addition 

 to the other advantages obtained. In order 



TO SECURE THE BEST RESULTS 



from the process, the latex must be strained free 

 from solid impurities, and all vessels kept per- 

 fectly clean. No time must be lost in putting 

 the rubber into the hot water after rolling or 

 pressing, and the sheets or biscuits must be kept 



separate and constantly moving for a sufficient 

 length of time for the rubberto acquire the ne- 

 cessary temperature throughout. In'all stages of 

 the preparation the rubber must be protected 

 from dust and other impurities. 



M Kelway Bamber, f.i.c , m.b.a.c, &c, 

 C/o. Messrs Gow, Wilson & Stanton, Ltd., 

 13, Rood Lane, E.G. 



With regard to the above instructions, which 

 have been largely circulated from London, I 

 found on visiting several estates that the 

 process was rarely carried out properly. 

 In several the water was barely lukewarm; 

 in others, and where the correct tem- 

 perature might have been employed to start 

 with, it was only maintained so for a few 

 seconds as the immersion of several thick sheets 

 of cold wet rubber rapidly reduced it. The 

 rubber was rarely immersed for the correct time ; 

 in fact, it was frequently only in the water for 

 a few seconds. It is absurd to imagine that 

 good results can be obtained by such methods, 

 and if the process is to be successful at all, the 

 instructions must be carefully and thoroughly 

 carried out. On only one estate that I visited 

 was this being done, and the result was ex- 

 cellent in every way and in no factory have I 

 ever seen a more uniform outturn of the palest 

 crepe and sheet. In addition to treating the 

 sheet or crepe by this method, i.e., immersion 

 after rolling once or twice, the scrap on the 

 trees should be collected immediately it has 

 coagulated and immersed in water at 170°-180° 

 F. so as to prevent darkening and it can then 

 be rolled and manufactured in the usual way. 

 — M. K.B. — Straits Agricultural Bulletin, August. 



A NEW USE FOR LALANG. 



Thus In Tinland: — It may not be generally 

 known that lalang played an instructive Govern- 

 ment function at the Agri-Horticultural Show. 

 It is a positive fact that the pillows supplied to 

 those favoured Government visitors at the Vic- 

 toria Institution, catered for at the rate of $7 

 a day, were stuffed with lalang. This is per- 

 haps the first instance on record of that useful 

 grass being devoted to domestic purposes. We 

 understand patent rights are being applied for 

 this product, but whether it carries comfort 

 rights is questionable. None of the lalang pil- 

 lows formed an exhibit at the Show. — Malay 

 Mail, Aug. 17. 



SISAL FIBRE CULTIVATION IN INDIA. 



An Indian planter writes on the subject of 

 sisal fibre cultivation in India that although 

 agaves and nettles thrive tolerably well all over 

 Eastern Bengal an extensive tour in those dis- 

 tricts has demonstrated that the best are pro- 

 duced in the calcareous country stretch- 

 ing along the cliff formation from the eastern 

 end of the Garo Hills on the extreme west to the 

 Loobah River on the east. As this stream is 

 reached the strata twist abruptly to the north, 

 and perceptible difference is at once apparent in 

 the plants, although the cursory tourist might 

 not observe it. Within the boundaries men- 

 tioned he states sisal fibre at two years old at- 

 tains a height of seven to ten feet, the leaves 



