884 The Supplement to the Tropical Agriculturist 



the contents. Rubber has a curious knack of 

 shrinking en voyage and moulds itself surpris- 

 ingly to fit any ledge or projection in the package. 



Tackiness. 



The enzyme of tackiness appears to nourish in 

 the air space left by the shrinkage of rubber in 

 the package. It might be worth while (where 

 this is known to occur frequently) to paint the 

 inside of the package with a 10 per cent, solution 

 of formaline. Personally I should be tempted 

 to spray all crepe especially with a solution of 

 formaline not less than 2 per cent and not more 

 than 5 per cent., but the manufacturers are so 

 suspicious of any innovation that such a course 

 is at present out of the question. 



Chemistry. 



Very little progross has recently been made in 

 this department. The various committees ap- 

 pointed at the Exhibition of 1909 frankly re- 

 ported that they had no completed results to lay 

 before the Conference. One of the manufac- 

 turers, who was mainly interested in the electri- 

 cal applications of rubber, said that he objected 

 to the presence of acetic acid in rubber as this 

 made it useless for his purpose. It was pointed 

 out that it was impossible by even prolonged 

 washing to remove all acetates as they were 

 incorporated with the albuminates in the latex 

 and were insoluble. It afterwards became evi- 

 dent, however, that the objection was to free 

 acid in the interstices of crepe, or even more so 

 to " block " made from crepe containing free 

 acetic acid. 



It is therefore 



VERY IMPORTANT TO THE PLANTER 



that all/ree ncid should be washed out oftherubber 

 at as early a stage as possible Free acid can be 

 easily detected in an instant by the use of 



BLUE LITMUS PAPER 



a chemical of trivial cost. 



Pure Water on Estates. 

 It is increasingly evident that very great im- 

 portance should be paid to the water supply 

 of the rubber factory. In wet weather especially 

 every trace of sand or matter in suspension 

 shauld be removed. A case in which purity of 

 water supply directed expert attention to the 

 sample was that of Nikakotuwa estate, which 

 from this cause was of stand-out quality. 

 Dust. 



This should be avoided as much as possible 

 especially in the coagulating room, which should 

 be kept as clean as the best managed dairy. 

 Wire blinds should cover the windows. 



Effects of Lights on Rubber. 



There is an increasing balance of evidence to 

 show that coagulation is more satisfactory in the 

 dark or in a very dim light. External Venetian 

 jalousies would effect this manipulated from 

 within. 



Coolness while Coagulating. 

 Except in the case of coagulating by steam 

 or smoke it appears that coagulating is most 

 successful in a cool temperature. 60 degrees 

 Fahrenheit is, perhaps, ideal, but this is rarely 

 possible without ice in the low-country. By 



the use of fans and wetted tats, however, a 

 certain measure of coolness is always obtainable. 



Drying Rooms and Vacuum Driers. 



A large number of the biggest producers of 

 rubber, especially in Malaya appear to be pre- 

 judiced against the use of Vacuum Driers. Be 

 this as it may, there appears to be little doubt 

 that the best rubber is produced at a tempera- 

 ture of 150 degrees Fahrenheit in a free Current 

 of air at the normal atmospheric pressure. It is 

 difficult to see how the vaccuum could have 

 any injurious effect, but perhaps it is that 

 errors of manipulation are difficult to detect in 

 in drieis used when the superintendent is not 

 actually present. 



Chemical Tests for Rubber, 



The brokers appear to value rubber entirely 

 by the old rule of thumb methods with which 

 we were made familiar at Peradeniya in 1906. 

 The great drawback to testing raw rubber even 

 chemically seems to bo that two samples of 

 rubber (giving identical results when tested 

 chemically and by the usual testa for breaking 

 strain, resilience, &c.) behave quite differently 

 when vulcanised. 



Resin, for example, is looked on askance by 

 many buyers, but actual tests have proved that 

 rubber containing 8 per cent, of resin has in cer- 

 tain cases given tip-top results from the manu- 

 facturers' point of view. The finest hard para 

 often contains quite high percentages of resin 

 compared with ordinary plantation. 



Over-rolling. 



There appears occasionally (not as a rule, how- 

 ever) to be a certain amount of injury done to 

 rubber by overworking on the rollers. This is 

 perhaps, most marked in scrap from bark (even 

 live bark, not dead and cankered stuff.) On the 

 other hand, there is the paradox that dead re- 

 covered rubber which has completely lost its 

 elasticity is often magically revived by rolling. 

 Summary. 



I hope that these remarks may prove of some 

 value to those practical planters in Ceylon who 

 were unable to attend the Rubber Exhibition, 

 I think I have said enough to show that an 

 enormous field remains open for investigation. 

 To sum up, I should think--(l) an ample supply 

 of clean water, (2) a cool, dark coagulating room, 

 and (3) a quick cure are the three great deside- 

 rata of rubber manufacture. 

 —"Times of Ceylon." J. R. 



TEA IN THE CAUCASUS. 



The heavy snow fall of the past winter in the 

 immediate vicinity of Batoum, combined with 

 the unusually cold weather experienced in 

 December, January and February last, did much 

 injury to tea plantations. A large number of the 

 older tea shrubs had their branches broken off 

 by the weight of snow, and the young plants 

 suffered much from cold. The yield of the 1911 

 crop is estimated at about 200,000 lb., or about 

 50,0001b. less than in 1910. The area under tea 

 in the neighbourhood of Batoum is slowly but 

 steadily being extended. A tendency of small 

 farmers to embark in the enterprise is apparent. 

 — Board of Trade Journal, Sept, 28. 



