December, 1911.] 



495 



Saps and Exudations. 



in a thousand different ways ; to see the 

 finished article as it issues from the 

 mould or the hydraulic press ; and 

 lastly, to study the methods used in 

 testing it and in ascertaining its value 

 for industrial purposes. The machinery 

 employed in the different stages of the 

 manufacture possess many features of 

 interest, aud it will be a source of some 

 surprise to find how widely the growth 

 of » ubber has become dispersed in many 

 different quarters of the world, and to 

 study the maps relating to this subject. 

 It will be possible from these maps to 

 obtain some general idea of the distri- 

 bution of the different varieties of trees 

 from which rubber is obtained aud to 

 see where each species preponderates. 



In order to aid the general reader to 

 obtain good information of the present 

 state of the rubber industry, a series of 

 articles by some of the leading experts 

 has been brought together. Thus Dr. 

 Philip Schidrowitz deals with the 

 chemistry of rubber, both raw and 

 vulcanized, and he indicates the lines on 

 which it has beeu attempted to produce 

 rubber synthetically by means of 

 isoprenp. He also discusses the various 

 uses of waste rubber aud the method in 

 which it is prepared for re-manufacture. 

 In connection with the attempt to 

 prepare rubber by chemical means, 

 which has always been held in terrorem 

 over the heads of the rubber planters, it 

 is interesting to note that in the present 

 display some specimeus are shown of 

 isopreue derived from starch, sugar 

 and even sawdust. The very volatile 

 liquid thus obtained is then condensed 

 by boiliug under pressure for three 

 days, when a certain proportion of 

 gelatinous material said to be pure 

 caoutchouc separates out, and it is 

 claimed that by tk e addition of enzymes 

 to the substance thus prepared it be- 

 comes possible to manufacture the 

 synthetic rubber there on view,, which 

 will, it is said, vulcanize well and 

 possesses all the proper, ies of the sub- 

 stance prepared from the latex of plants. 



In an article on " The Rubber Indus- 

 try, 'contributed by Mr.Herbert Wright, 

 the question of future supplies of the 

 raw material is fully investigated, and 

 some account is given of the multi- 

 farious uses to which rubber is now 

 applied. Mr. Wright, who had very 

 large experience on the spot, deals with 

 the new plantations in Malaya and 

 Ceylon and their yielding capacity, 

 and he shows that great changes are 

 imminent in the balance of power in the 

 rubber market. Brazil and Africa, from 

 which such large proportions of rubber 

 have been derived in times past, will 



shortly have to yield the premier place 

 to the plantation rubber, while Liver- 

 pool will ere long become a port of 

 secondary importance in the rubber- 

 trade as compared with London, which 

 may possibly have to deal with 3,000 

 tons of rubber monthly iu the near 

 future. 



A correspondent with intimate know- 

 ledge of the Stock Exchange gives his 

 views on the position aud prospects of 

 the rubber companies, aud takes a hope- 

 ful view of the situation. A valuable 

 article by Professor Robert Wallace 

 describes certain of the diseases aud 

 pests to which rubber plantations are 

 subject, and his observations deserve 

 careful consideration of the professional 

 rubber planter. It will be seen that 

 most of these foes to the rubber estate 

 are the outcome of careless clearing. 

 Some interesting and graphic accounts 

 are given of rubber collecting iu Brazil 

 and in the Amazon district by an 

 authority who has spent many years in 

 the country, and who is able to recount 

 from actual experience the difficulties 

 encountered by the Seringueiro and die 

 troubles of the estate owuer. On the 

 subject of the new method of obtaining 

 gutta-peicha from the leaf instead of 

 the trunk of the Isonandra gutta, some 

 facts are given on the authority of Dr. 

 Tromp de Haas, the able Superintend- 

 ent of the Government plantations at 

 Tjipetir, in Java. It is claimed that by 

 this plan of making use of the leaves a 

 very much larger quantity of gutta- 

 percha cau be secured from each acre 

 of plantation, and that ihe system is 

 less liable to cause injury to the tree 

 than the former process of tapping. 



Guayule rubber, obtaired from a 

 small bush or shrub covering vast areas 

 in. Northern Mexico and Texas, forms 

 the subject of a special article in which 

 a full account is given of the growth of 

 the Guayule plant and the mode in 

 which the rubber is secreted which 

 differs esseutially from that of nearly 

 all other known descriptions of that 

 substance. Special consideration is 

 devoted to the mechanical testing of 

 rubber, to the use of rubber as a mate- 

 rial for street paving, aud to many other 

 matters in relation to this subject which 

 are now attracting pubic attention. A 

 full description has also been prepared 

 of the Exhibition and of the collections 

 brought together by the different 

 rubber-producing countries, with notes 

 on the conferences in which the expert 

 authorities deputed by the various 

 Governments have taken part. 



A remarkable feature is the extent to 

 which the support of Governments of 



