and Magazine of the Ceylon Agricultural Society,— November, 1911. 469 



down so easily in groups of C 5 Hs and why its 

 combining capacity is represented by four atoms 

 of bromine for every ten atoms of carbon. 



Thiele's theory of partial valencies has been 

 invoked by way of explanation but this is itself a 

 subject of extremely doubtful character. 



Other formulae have been suggested but the 

 whole question is one which requires much fur- 

 ther investigation. 



Finally, it may be remarked that the terpenes 

 and their derivatives afford many examples of 

 optically active compounds which, however, do 

 not owe their activity to the presence of one or 

 more asymmetric carbon atoms but rather to the 

 asymmetry of the molecule as a whole. This 

 phenomenon, however, is not peculiar to the 

 terpenes and the question is too large for discus- 

 sion on this occasion. 



RUBBER EXHIBITION IN AMERICA. 



October 10th, 1911. 



Dear Sir, — I extract the following from the 

 India Rubber World of New York, in case it 

 does not come your way. 1 think it is worthy 

 of a place in your columns : — 



" At no time in the history of the rubber 

 trade could rubber manufacturers view a 50 per 

 cent export duty on Brazilian rubber, and a 

 restriction of the Acre product with greater 

 calmness. Factory stocks have accumulated, 

 reclaimed rubber is understood and manufac- 

 tured on a greatly increased scale here and 

 abroad, plastics, such as mineral rubber, are 

 utilized the world over, and plantation receipts 

 are constantly growing. 



" If Brazil does as she plans, as she certainly 

 has every right to do, rubber will undoubtedly 

 be higher for a time. The result, however, will 

 be a tremendous increase in planting, a further 

 exploitation of the lesser rubber producers, the 

 substitution of many plastics for rubber where- 

 ever it is possible, and the final disappearance 

 from the market of all wild rubber, the cost of 

 collection of which is above 50 cents a pound." 



Since my stay in the United States, I find that 

 plain rubber is coming into continued favour 

 with the manufacturers in this country. The 

 only thing is, they do not know enough about it. 

 I have now arranged to hold an International 

 Rubber and Allied Trades Exhibition under the 

 auspices of the International Exposition Com 

 pany, a body incorporated under the laws of the 

 United States. Their building in the Hew Grand 

 Central Palace, 46th to 47th Street and Lexing- 

 ton Avenue, New York City, is one of the most 

 palatial buildings in the world. 



The dates arranged are the 23rd of September, 

 1912, to October 3rd, 1912, and a very influential 

 committee is now being formed, and my friend, 

 Mr Henry C Pearson, the Editor of the "India 

 Rubber World," will be the active Vice-Presi- 

 dent of the undertaking. Full particulars will 

 be sent you in due course, and I trust the ex- 

 position will have your kind support. — Yours 

 very truly, 



A. STAINES MANDERS, 

 Organising Manager. 

 75, Chancery Lane, London, W.C. 



SILK COTTON OR KAPOK. 



The following particulars concerning the silk- 

 cotton tree and the fibre and its uses are taken 

 from the Bulletin of the Imperial Institute, 

 Vol. IX (1911), p. 121. 



Kapok is a fine fibrous material, somewhat re- 

 sembling cotton, but weaker and more lustrous, 

 derived from the tree known as Eriodendron 

 anfractuosum which occurs in the Dutch East 

 Indies, India, Ceylon, tropical Africa, the West 

 Indies, Mexico and Central America. The fibres 

 arise from the inner wall of the capsule and 

 surround the seeds. 



The kapok tree grows at the sea-level and up 

 to an altitude of 3,000 or even 4,000 feet, but 

 gives the best yield and quality of fibre when 

 situated at less than 1,C00 feet above the sea. 

 It is said to flourish best on a porous, sandy 

 clay soil, in a climate with a dry east 

 monsoon, and to be capable of withstanding heavy 

 rains and resisting long periods of drought. 



The propagation of the tree can be easily 

 effected by means of either cuttings or seed. In 

 the latter case the seed is sown in nurseries, and 

 is only lightly covered with earth. If the soil 

 is poor, it is recommended that stable manure 

 should be applied about ten days before sow- 

 ing. The seed should be planted in rows at a 

 distance of 10 to 12 inches. When the young 

 plants are about 5 or 6 inches high they should 

 be no longer shaded but exposed to the sun. If 

 the plants do not obtain plenty of sunshine, 

 they grow thin and lanky. The seedlings are 

 planted out when from eight to twelve months 

 old. In Java, kapok trees are commonly plan- 

 ted about 12 to 15 feet apart along the roads in 

 the coffee and cacao plantations. When the 

 trees are grown in special plantations, they 

 should be placed about 18 feet apart (about 144 

 trees to the acre), for if planted more closely 

 they soon interfere with one another. The trees 

 commonly attain a height of 30 feet, but some- 

 times grow to 50 feet or even more. 



Before transplanting, it is advisable to strip 

 off all the leaves and to cut the stem down to a 

 height of 1J to 2 feet, and also to cut the chief 

 roots so as to make stumps of them. If the top 

 is not cut it will usually die down to the ground. 

 The trees subsequently require very little atten- 

 tion, but the soil must be kept free from weeds. 



During the early years of growth other plants 

 can be cultivated between the young trees, In 

 Java it is a common practice to grow pepper in 

 this way, but it should not be planted before 

 the kapok trees are three or four years old. 



The trees begin to bear in the third or fourth 

 year, but sometimes not till later: The crop is 

 never very large until the sixth year. A large 

 tree brings 1,000 to 1.500 fruits to maturity per 

 annum, each of which contains about 7 to 1"2 

 grammes of dry fibre. Hence, on an average a 

 well-developed tree may be expected to give an 

 annual yield of § to 1$ kilogramme (or about \\ 

 to 2j lb.) of clean fibre. 



The tree flowers in April or May, and the 

 fruits mature at the end of October or in 

 November. As the fruit ripens it becomes yel- 

 lowish-brown and then begins to open. As 

 soon as this point is reached, the fruits are 

 gathered by means of long bamboo poles bearing 

 small hooks at the upper ends. They are then 



