572 



The Supplement to the Tropical Agriculturist 



A NEW RUBBER SUBSTITUTE. 



Russian Chemist's Remarkable Imitation. 



It has been left to a Russian chemist of the 

 name of Plinatus, to make what certainly is a 

 "real" imitation rubber. After three years of 

 persistent experimenting and inventing, and 

 what is perhaps more important, the discovery 

 of entirely new chemical re-actions, an imitation 

 rubber has been produced which to tho eye is 

 as real as the purest rubber. This 



PLINATUS RUBBER HAS BEEN PATENTED IN 

 GERMANY, 



and patents have been applied for in all foreign 

 countries. In Paris one of its many uses has 

 been the introduction of Plinatus, rubber for both 

 pneumatic and solid rubber tyres. This may 

 seem contradictory, but the explanation is sim- 

 ple ; for outer tyres Plinatus cannot be used, 

 but for the filling of the inner tubes, it replaces 

 air in the pneumatic tyres, and it replaces real 

 rubber in the solid tyres. Cab proprietors in 

 Paris have experimented with it for 18 months, 

 and so satisfactory are the results that the Ger- 

 man Company which bought the German rights 

 and started a factory on the 1st instant, have 

 contracted with the patentees to establish a 

 branch factory in Paris on or before the 1st 

 December next, and in the meantime the 

 German Company are filling the wheels for 

 Paris cabs. Speaking of the substance itself, 

 we might point out that Plinatus rubber is 



TOUGH, FIRM, EXCEPTIONALLY PLIABLE, HIGHLY 

 ELASTIC AND OF THE SAME CONSISTENCY AS 

 REAL RUBBER. 



To the touch it is identical with rubber, and 

 in appearance difficult to distinguish ; it can be 

 made soft, hard or leatherlike according to 

 requirements. The specific weight varies from 

 0'6 to 1*18 the tensile strength by the soft rubber 

 is 20 to 25 per cent, less than that of real rubber. 

 It withstands pressure to almost a higher degree 

 than rubber itself. The artificially introduced 

 air bubbles give it an exceptionally strong 

 expanding power. Prepared as soft rubber it 

 withstands a pressure of about 10 lb. per qcm. 

 The hand rubber up to 40 lb. per qcm. Light 

 has no influence upon it ; further it is absolutely 

 insoluble in benzine, other, turpentine, petro- 

 leum, tetrachlor acid, etc., and entirely indif- 

 ferent to all mineral and vegetable oils. It is 

 the only rubber real or imitation that will with- 

 stand these oils, and at the same time not swell. 

 The prime cost of production is from 3d. to 8d. 

 per lb, depending upon the uses for which it is 

 intended. Coming back to one of its main 

 uses, cab and other vehicle tyres, Plinatus rubber 

 promises to cause a revolution in the trade. 

 The inner tubes are rilled with Plinatus rubber 

 and produces a tyre of exceptional strength 

 and durability. The drivers of Plinatus rubber 

 tyres do not know the meaning of puncture 

 or bursted tyres and drive with the same perfect 

 ease and comfort as the best pneumatic tyre. Com- 

 pared with solid tyres it has the enormous ad- 

 vantage in cost and further in durability and 

 ir. elasticity, etc., hitherto only connected with 

 pneumatic tyres. At the present time 



ARRANGEMENTS ARE IN PROGRESS TO SUPPLY 

 1,000 CABS IN PARIS 



with tyres filled with Plinatus rubber. So 

 many imitation rubbers have been placed before 

 the trade, that it is small wonder that people 

 get sceptical, but we understand that the paten- 

 tee is willing to receive through his represen- 

 tatives in Berlin or London four wheels of a 

 cab or brougham, which he at his own ex- 

 pense will fill with Plinatus rubber and return, 

 that the owner thereof may convince himself 

 as to the merits of "Plinatus" rubber. "Pli- 

 natus" rubber, it should be stated, does not 

 get hard or brittle, and time does not rob it 

 of its elasticity. It is long past the experimental 

 stage, and arrangements are pending for the 

 sale of the British rights. Another feature of 

 no little importance is the fact that a very 

 small sum suffices for the starting of a factory 

 on a small and yet absolutely paying scale. The 

 British patent rights are in the hands of Mr. 

 Friedrich Lehfeldt, of Berlin, S. W. 68, or his 

 London agent, Mr. A M Lehfeldt, 50, Bucking- 

 ham Palace Road, S. W. Either of these gentle- 

 men will be pleased to give interested parties 

 tho requisite information or to take them over 

 the factory at Kref eld.— Financial World, Nov 13. 



PROPORTION OF SCRAP TO FINE 

 RUBBER. 



Our correspondent "CW H '' elsewhere raises 

 an interesting question when he asks what 

 proportion planters regard as a fair average 

 for the amount of Scrap, collected in course 

 of tapping any particular area, to bear to the 

 whole crop collected at any one time. He 

 mentions cases of 5 and 40 per cent, and also 

 of planters who say they never have any Scrap. 

 The average doubtless lies between the two first, 

 while the last group must be simply r inverting 

 their Scrap into something else. We would like 

 to hear the opinions of leading rubber planters 

 on this interesting point. 



November 29th. 

 Dear Sir, — During the operation of tapping 

 rubber trees more or less latex is spilled over 

 the adjacent bark ; and when the "spillings" are 

 sufficiently set, they are collected and brought 

 to the factory as " scrap." Scrap being more or 

 less mixed with impurities, its value is naturally 

 leas than the product of pure latex ; but where 

 appliances are at hand, it is possible to clean and 

 convert scrap into dark-coloured crepe, which is 

 well appreciated by the trade and commands a 

 very fair price ; and in such cases none of the 

 produce is sent to market as scrap. When this 

 is the case, if the question is asked, " What pro- 

 portion does your scrap bear to your No. 1.," the 

 answer sometimes is: "Oh! we have no scrap "; 

 but I think that answer rather evades the ques- 

 tion. 1 believe it is pretty well established that 

 weather conditions greatly influence the amount 

 of spill in the process of tapping ; but what I 

 should like to find out is — what is the consensus 

 of planting opinion as to the proportion which 

 scrap should bear to the whole crop on a well- 

 managed place with fairly expert tappers, 



