298 



THE INDIA RUBBER WORLD 



[March 1, 1914. 



As to Hevea, the opinion was expressed that provided longer 

 contracts were permitted by the government, the cost of pro- 

 duction in German Ea.st Africa would he about on a level with 

 tliat in Eastern Asia. 



Most Kamerun rubber phmtations Iiavf tlie advantage over 

 those of Asia that they have a supplementary crop, but this 

 gain is partially offset liy the restricted yields of the Kickxia 

 and the inimatifre age of the Ilevca. 



The deticient means of transport for provisions operates in- 

 juriouslv on the wild rubber industry of South and Xeu 

 Kamerun, the construction of new railways being intended to 



remedy these conditions. Exports of rubl)er from Kamerun 

 were: 1910, 1,960 tons; 1911. 2,700 tons. 



At the meeting the following resolution was adopted as a re- 

 sult of the discussion ; 



"The present depressed state of the rublx-r industry in South 

 Kamerun causes the Imperial Economic Committee to request 

 the temporary suspension of the duty on rul)l)er exports from 

 Kamerun 



Rubber, it is officially stated, is of much less importance for 

 Togo than for German East Africa and Kamerun, exports for 

 1911 and 1912 l)eing about IHO and 100 tons, respectively. 



The Editor*s Book Table. 



Till-: CIIKMISTRV 0|- Kt'ISBKR. \\\ \\. D. PORRITT, B. SC. 

 (London). l.nn*ion. 1913. Giiriiev & lacksoii. fCIotli, 96 pages, 

 7v.vl 



1\ his position nf chief chemist to the North Uritish Kubber Co.. 

 Limited, of Edinburgh. Mr. Porritt has had exceptional facili- 

 ties for the compilation of this valuable handbook — chiefly 

 intended for those interested in rubber from a chemical 

 point of view. Altho the treatinent of technical practice has 

 thus been limited, the details given afford a clear insight into 

 the chemical questions involved in that branch of the subject. 



Mr. Porritt divides his comprehensive work into six sec- 

 tions, covering the entire ground. Under the lirst two he 

 deals with the properties and constituents of crude rubber. 

 as well as its purification, constitution and derivatives. The 

 two next sections discuss the methods and theories of vul- 

 canization, including the constituents of mixings, hot vul- 

 canization (with admixed sulphur), cold cure (with sulphur 

 chloride), absori>tion theory of vulcanization and other im- 

 portant points. 



With the fifth section a subject nf more general interest is 

 reached. Waste rubber may be broadly divided into two 

 classes; (a) unvulcanized, (b) vulcanized. The radical dif- 

 ference between the two is that the former is soluble in 

 solvents and is soft and plastic, while the latter cannot be 

 obtained in solution without treatment entailing molecular 

 destruction. 



Unvulcanized waste consists of trimmings from shoes, 

 football i)ladder sheet and other material. It generally contains 

 no fabric and is used in the factory without treatment. In some 

 cases it is necessary to remove the fabric before the proofing 

 becomes available. This is effected by treatment with naphtha, 

 wringing and subsequent evaporation of the solvent. 



X'ulcanizcd waste rubber may contain the following con- 

 stituents: vulcanized rubber, inorganic filling agents, free 

 sulphur, organic matters and foreign material. This waste 

 is, moreover, non-plastic, and will not mill on the mi.xing 

 rolls. .\s it is already compounded, its use is necessarilv 

 limited to a particular class of goods. It has thus been tlie 

 aim of every inventor in this field to remove all the com- 

 bined sulphur and fillings, obtaining the rubber portion in 

 its original plastic soluble form. 



The final section, treating of synthetic caoutchouc, deals with 

 the preparation of isoprene and butadiene, as well as the obtain- 

 ing of rubber from isoprene and its homologues. This mono- 

 graph in its convenient form will prove of value to all interested 

 in the chemistry of rubber, in theoretical nr practical form. 



INIIfSTRt.M. RK.SK.\R(II IN .\MERIC.\. V.\ ARTIIIR D. LITTLE, 

 l^oston. 1913. t Paper, Svo, li pages.] 



In the address recently delivered by Mr. \. D. Little, as presi- 

 dent of the American Chemical Society, at Rochester. X. V 

 (and now reprinted), he touched upon the origin and develop- 

 ment of the principal inventions on which modern industry is 



founded. Referring to that of automobiles, he mentioned the 

 fact that one tire manufacturer spends $100,000 a year on his 

 laboratory, thus indicating the value of industrial research to 

 that industry. 



DEK .M.\.\lllOT-K.\UTS(;ilfl< (MANIHOT RUUBER). I'.Y PRO- 

 fessor Dr. A. Zimniermann, Director of the Imperial Agricultural 

 Institute, Amani, German East Africa. Jena, 1913. Giistav Fischer. 

 [Paper. 342 pages, with 149 illustrations.] 



In this coiTiprehensive voluine Professor Zimmermann has told 

 the story of Maiiihot rubber, under the various aspects of its 

 botany, distribution, ciilfivation. diseases, collection and prepara- 



M.\N.\GER E. KoHLER, St.xnding Beside ll-YE.\R-OLn Manilint 

 Glaciovii Tree on Lew.\ Pl.\nt.\tiox (G. E. A.). 



tion. As it is known, there are 129 varieties of Mauiliot, of 

 which 6 contain rubber — these being the following ; Glaciovii, 

 Dichototna, Piaiihycnsis. Hcftafhylla, Violacca and Prcciosa. 

 Of these the first four are the most important. 



Mdiiihot Cla::ioz'ii was discovered liv Dr. Glaziov, the French 



