228 



THE INDIA RUBBER WORLD 



[January 1, 1915. 



THE JINRIKISHA AND ITS TIRES IN CHINA. 



From Our Japanese Correspondent. 



"PUREE kinds of jinrikishas are used in Manchuria — iron, 



*■ rubber and pneumatic tired, at prices from $30 to $50. The 

 pneumatic tire is intended for use with the Chinese type of 

 jinrikisha, which is rather .smaller than the other two. An esti- 

 mate places the total number in various parts of Manchuria at — 

 Chanchin, 650; Futien, 3,000; Reijon, 127. 



Rubber tires are imported into Manchuria either through 

 Chinese merchants in Futien, who gather them from other dis- 

 tricts, or through Japanese dealers at Chanchin, who buy from 

 the manufacturers in Japan. About 70 per cent, of the total arc- 

 solid rubber tires and 10 per cent, rubber pneumatic tires. The 

 solid rubbi ised on these jinrikishas cost $8.50, and the 



pneumatics $12.50. At Futien rubber tired jinrikishas are sell- 

 ing at from $36 to $45 in the cheaper grades, up to $56.25. Solid 

 tires are imported from Tokio and Osaka. 



The carriage's, wheels, tires and other parts of jinrikishas are 

 imported principally from Osaka, and assembled by the Japanese 

 merchants at Futien, who sell the vehicles to Chinese dealers in 

 completed form. I he latter distribute them to private consumers 

 on the instalment plan. 



Healing with other parts of China, there arc in Chefoo 450 

 jinrikishas, those using solid rubber tires costing from $18 to 

 $23 for common to $36 for superior grades. Wheels in con- 

 junction with solid rubber tires cost $9 a pair. Foreigners have 

 shown a preference for jinrikishas with solid rubber tires, but 

 the Chinese have continued to use the cheaper iron-tired vehicle. 

 It is anticipated, however, that improved roads will develop the 

 use of rubber tires. 



Shanghai has two kinds of jinrikishas, the Foboche with a 

 rubber pneumatic tire — of which there are about 10,000 — and the 

 Vajiche, numbering some 2,000, with iron tires. In addition there 

 are about 2,500 Foboche for private use. The 12,500 Foboche used 

 in Shanghai are fitted to the extent of 80 per cent, with pneu- 

 matic rubber tires, of which 30 per cent, come from the Dunlop 

 Rubber Co. (Far East), Limited, of Kobe, whose manufactures 

 are guaranteed for 6 months. 



In addition to the Dunlop company, the Michelin company 

 does an excellent business in tires, the Foboche having been 

 originally a French article, and most of the persons hiring out 

 jinrikishas being Frenchmen. The French goods, while not 

 guaranteed and slightly dearer, are said to be rather better than 

 the Dunlop make. Besides the Dunlop and Michelin companies, 

 the Continental Rubber Co., a German concern, supplies 20 per 

 cent, of the demand under a six months' guarantee. 



The jinrikishas in Shanghai require about two pairs of tires 

 each in a year, or for the 12,500 Foboche in use, 25,000 pairs 

 annually, with a value of $200,000 on the basis of $8 a pair. 



In Hong Kong there are 2,200 jinrikishas, the majority of 

 which have solid rubber tires, imported from the Dunlop Rubber 

 Co., London, and other British and German firms. 



Pneumatic rubber tires are not used in Hong Kong, the un- 

 evenness of the. roads being responsible for the demand for a 

 strong, solid tire. The Hong Kong jinrikisha makers import the 

 parts from Great Britain, Germany and Japan, and ship their 

 products to other parts of China. The largest maker in Kong 

 Kong is Koche Konau, with a capital of $25,000 and 800 vehicles 

 for hire. 



TAPPING ON ALTERNATE DAYS. 



With a view to prevent over-production, the Malacca Planters' 

 Association recently agreed to the plan of tapping on alternate 

 days. A meeting of the body named favored a general reduction 

 of production by 30 per cent. 



DECOMPOSITION OF RUBBER THROUGH 

 MICROBES. 



IN dealing with the above subject, N. L. Sohngen and J. G. Fol 

 *■ lately considered the following questions: 



Are the mechanical properties of the portions colored by the 

 action of microbes different from those of the uncolored rubber? 

 Is there consequently any reason for a lower valuation of colored 

 rubber? Is the hydro-carbon in rubber subject to the attacks 

 of microbes? 



In the second part of the article the authors speak of the micro- 

 organisms in rubber and their influence upon its mechanical 

 qualities. They first give a review of the subject and record 

 their experiments regarding micro-organisms and the mechanical 

 properties of spotted rubber. I hey deduce the opinion that the 

 microbes forming the spots beyond the discoloration exercise 

 no injurious effects on the rubber. Thus a lower valuation of 

 spotted rubber cannot be defended. According to their opinion 

 it is, however, advisable to prevent the growth of the micro- 

 organisms, which can be accomplished by a suitable arrange- 

 ment of the drying chambers. It is only at a certain degree of 

 moisture that microbes are developed in rubber. 



The third part of their article treats in detail of the microbes 

 which attack rubber, the following results being obtained by the 

 authors : 



1 . On air-dried rubber ( containing 0.5 per cent, of water) 

 micro-organisms cannot be developed in consequence of the lack 

 of water. 



2. When water is present in abundance, commercial rubber 

 is a medium for the development of many kinds of bacteria and 

 germs, to the detriment of the albumens, sugars and resins 

 which are present. Some kinds produce red, black or brown 

 spots without noticeably changing the mechanical properties of 

 the rubber. 



3. Two kinds of actinomyces often found in garden soil and 

 sewer water, actinomyces elastica and actinomyces juscus, are in 

 a position to attack and assimilate the hydro-carbon in rubber. 



4. From these microbes an enzyme attacking rubber and 

 soluble in water is not obtained by separation. 



5. The knowledge of the facts — first that the development of 

 microbes can take place in moist rubber, when the rubber hydro- 

 carbon is not decomposed, and the mechanical properties do not 

 change, but where pigments are often given off, which diminish 

 the market value of the rubber; and secondly — that there are 

 kinds of actinomyces which can positively attack the hydro- 

 carbon of rubber, and thus lower the viscosity, makes it desir- 

 able to again urge that it is of the greatest practical interest 

 to prevent as far as possible the development of micro-organ- 

 isms in rubber. The growth of microbes is prevented by the 

 rubber being dried on the plantation as quickly and carefully as 

 possible, in suitably arranged drying chambers. 



[G. S. Whitby (see V. 25, P. 596 to 621 of 8tli International Congress 

 of Chemistry, New York, 1912) concluded that tackiness in rubber was 

 caused by an enzyme, but V. Rossem (Caoutchouc et Gutta Percha, Febru- 

 ary '13, P. 6981, aihl Chem. Abs., '13, P. 1811) attacks these views. 1 



Replete with information foi rubber manufacturers. — Mr. 

 Pearson's "Crude Rubber and Compounding Ingredients." 



LATEX DENSITY EXPERIMENT. 



A number of experiments were made during the last year to 

 test the specific gravity of latex, from which a suitable latex 

 hydrometer has been constructed. This machine is made by J. J. 

 Griffin & Sons, London, and is intended for factory controls. 

 Experiments were carried out to test the comparative value of 

 formic and acetic acids for Hcvea coagulation. It has been 

 suggested that if the rubber prepared with formic acid proves 

 equal to that produced with acetic acid the former should be 

 substituted for the latter, being cheaper and more economical. 

 It would be still cheaper but for the high freight charged on it 

 by the steamship companies as being dangerous cargo. 



