and Magazine of the Ceylon Agricultural Society.— August, 1911. 



It was announced that Professor Huber had 

 undertaken to form a branch in Brazil. He ad- 

 dressed the meeting, and urged that the Govern- 

 ments of all countries should take steps to see 

 that rubber sent out under a well-known name 

 was really rubber of that kind, and not a mixture 

 or a substitute. Governments should see that it 

 was properly stated where the rubber came from 

 and from what tree. He knew of cases where 

 rubber was supplied under a well-known name 

 which was of a different make and from a dif- 

 ferent tree. He also advocated the forming of 

 museums of standard qualities and kinds of 

 rubber. 



The conference was resumed on Friday. Dr. 

 Torrey presided. 



Dr. W Carnegie Brown, m.d., m.r.c.p., read 

 a paper on 



HYGIENIC CONDITIONS AND THE MAINTENANCE 

 OF HEALTH ON RUBBER PLANTATIONS." 



In the course of his address he said that the 

 development cf the industry had led to a huge 

 demand for labour, and the influx of coolies had 

 naturally led to remarkable facilities for the 

 spread of disease. A large number of Europeans 

 had gone to make their homes in the tropics. 

 Apart from the fact that the indigenous popu- 

 lations were deeply affected, many of the 

 labourers, and especially their children, though 

 showing no signs of illness, harboured the germs 

 of malaria and other parasitic disorders, and 

 were consequently a readily available source of 

 contagion, of which the most frequent victims 

 were the other immigrants, and especially the 

 highly-susceptible new arrivals from Egypt. 

 There was, therefore, little cause for surprise 

 that serious outbreaks of tropical disease were 

 not unusual. During the last two or three 

 years no question had been so frequently asked 

 him as "Is the climate very deadly?" No 

 doubt, most of the estates were naturally in- 

 salubrious, but the causes of tropical disease 

 were now so well known that almost compete 

 prevention was by no means difficult. The 

 drainage and cultivation necessary for the 

 successful production of rubber were power- 

 ful aids to sanitation, and on a well-man- 

 aged estate there should be no epidemics 

 and very little serious illness. Intelli- 

 gence and constant vigilance were required, 

 but, given these essentials, the death-rate 

 should be scarcely higher than in Europe, and 

 with care in eating, drinking, and other mat- 

 ters, an assistant should be as healthy as on 

 any farm in Yorkshire. But he must be a 

 picked man, of good physique, not big or fleshy, 

 with a good family history ; no tendency to 

 alcoholism, insanity, or tubercle, and all organs 

 — especially the heart — sound. Dr. Brown went 

 on to comment in very strong terms on the 

 negligence of the authorities in doing little or 

 nothing to arrest the disease which had grown 

 rapidly of late years in Singapore and other 

 places. In 1892 the death rate at Singapore was 

 31 - 27, in 1902 it was 5ni,and according to the 

 latest reports it was worse than ever. Malarial 

 fever was very rife*. He compared this with 

 what had been done at Santos and other places. 

 In 1900 the death rate of Santos was 70 per 

 1,000; in 1903 drainage and sanitary work was 

 undertaken, cleanliness enforced, and a good 



water supply obtained, with the result that 

 since 1905 there had been no case of yellow 

 fever, and the death rate was down to 22 per 

 1,000. In Sorocaba yellow fever had been got 

 id of. In Manila the Americans at once under- 

 took to spend £800,000 for waterworks. He 

 also instanced Panama as having been reformed 

 from a deadly, fever-ridden place into one as 

 healthy as Hampstead. It was possible to en- 

 tirely get rid of malaria, which was spread by 

 mosquitoes, simply by well-understood sanitary 

 precautions. It was only necessary to drain 

 and fill up swamps, keep a sanitary staff to look 

 after the natives, and especially look after the 

 segregation of the sick and particularly of the 

 children. Many of the rubber estates had been 

 made free of malaria, and all of them could be. 

 The same thing applied to anky-lostomes and 

 small-pox. 

 Dr. Henricksen read a paper on 



" THEORY OF VULCANISATION," 



a subject about which much was heard some 

 ten years ago, but which came to more or less 

 of a standstill. Nothing had been said on it for 

 a long time that was of much consequence, 

 until two or three years ago, when there was 

 a renewal of research and literature on the 

 subject, with the result that an entirely new 

 aspect had been given to the matter. There 

 were, he said, two proposed theories for ex- 

 plaining the phenomena of vulcanisation — one 

 chemical and the other physical. The newer, 

 or physical, theory had been advocated specially 

 by Dr. Ostwald who held that the taking up 

 of the sulphur, or protochlorides of sulphur, 

 by the rubber was exclusively a surface action, 

 or absorption, The older chemical theory was 

 that the changes that took place in vulcanisa- 

 tion were associated with the formation of a 

 series of definite compounds of rubber, with 

 sulphur or protochloride of rubber. Experi- 

 mental evidence had been offered in support 

 of each. Dr. Henricksen reviewed all these 

 experiments, and concluded by saying that 

 physico-chemical methods, and, especially the 

 laws of reaction, kinetics were able to offer 

 fruitful suggestions for a systematic and scienti- 

 fic investigation of vulcanisation phenomena, 

 as well as for practice. 



Later in the day an important statement 

 was made by Mr. Clayton Beadle as to the 

 amount of 



ACETIC ACID IN PLANTATION RUBBER. 



It had been found by testing that the acetic 

 acid used to procure coagulation of the latex 

 on the estates could be practically all washed 

 out, and also that there was in washed planta- 

 tion rubber less acidity than was found in fine 

 hard Para, the acidity of which was due to the 

 absorption of acetic acid during the smoking 

 process which it underwent. 

 Mr. Jaques read a paper on the 



ADAPTABILITY OF RAW RUBBER FOR MANUFACTUR- 

 ING PURPOSES, 



in which he stated that, generally speaking, the 

 physical qualities of vulcanised No. 1 latex com- 

 pounds were identical with those characteristic 

 of hard-cured Para. The tensile properties of 

 the cultivated rubber were usually equal to or 

 of a slightly lower order than, indigenous Para, 



