and Magazine of the Ceylon Agricultural Society. 



detracts from its " nerve " and elasticity 

 and consequently lowers its value in the 

 market. A chemical has now been dis- 

 covered to take the place of acetic acid. 

 The discoverer of the new process is MrD Sand- 

 mann, of Berlin, a Judge of the Arbitration 

 Court in that city and a member of the Munici- 

 pal Council and Chamberof Commerce of Berlin. 

 Mr. Siiidmann is at present in Ceylon on his 

 way to Germany after a lengthy tour, and this 

 morning (September 21st) he gave 



A DEMONSTRATION OF HIS METHODS 



of coagulating latex at the Henaratgoda Gardens. 

 The demonstration was made in the presence of 

 Mr, M. Kelway Bamber (Government Analyst), 

 Mr. M. Hohl (Manager of the Manure Depart- 

 ment of Messrs. Freudenberg & Co.), and two 

 representatives of the press. Mr. Sandmann 

 calls his invention " Purub," a curtailment of 

 the words " pure rubber.'' According to him 

 it is a preparation of fluor, a well enough known 

 chemical. The preparation itself is of course the 

 secret of Mr Sandmann and the Company to which 

 he has sold his patent rights. The demonstration 

 was held in the little laboratory in the Gardens 

 and was conducted after the following manner: — 

 Half a litre of latex (l/9th of a gallon) extracted 

 from trees in the Gardens were poured into three 

 chemical basins, the exact proportions being 

 440 C. C. latex and 1,320 C. C. water. Into one 

 of these was added the usual quantity of acetic 

 acid, 30 C. C. diluted in water — 1 in 80. Into the 

 other two were added J a gramme of 'Purub.' 

 The basins were covered and after an interval 

 when the covers were taken off the latex treated 

 with 'Purub' was found to have nicely coagu- 

 lated, while the latex treated with the acetic 

 acid had, of course, not completed the coagu- 

 lation stage.Mr Sandmann claims for 'Purub' 

 that it stops the decomposition of the rubber 

 from the moment it comes in contact with the 

 latex and that it preserves its moisture, en- 

 abling it to be shipped with 9 to 10 per 

 cent of moisture; whereas when acetic acid 

 is used, the rubber only retains about 1 per 

 cent of moisture by the time it is dry enough 

 for shipping and if it is shipped before it is 

 quite dry it gets mouldy and tacky. In any 

 case the almost total absence of moisture 



REDUCES THE VALUE OF RUBBER 



considerably from the manufacturer's point of 

 view, while the presence of it to the amount of 

 9 to 10 per cent rendered possible, according 

 to Mr Sandmann, by the use of " Purub," in- 

 creases the commercial value of the rubber 

 correspondingly. The great advantage of 

 "Purub" over acetic acid, says the inventor, 

 is that it immediately stops putrefaction 

 which sets in as soon as the latex leaves 

 the trees. When acetic acid is used, the 

 putrefaction continues until the rubber has 

 been thoroughly dried by which process the 

 rubber loses its elasticity and a great deal of 

 its commercial value. By using "Purub" the 

 rubber can be shipped when it is only partially 

 dry and with a percentage of moisture in it 

 that keeps it in splendid marketable condition. 

 A small quantity is sufficient to coagulate a 

 large quantity of latex, the proper proportion 

 being two grammes to a litre of latex. It will 



be found a little more expensive than acetic 

 acid, but according to Mr Sandmann, its use is 

 bound to result profitably to the grower. To his 

 own knowledge rubber treated with "Purub" and 

 exported from East Africa fetched 20 per cent 

 better prices in the London market than rubber 

 treated without it. The use of "Purub" was 

 as beneficial in the case of castilloa and ceara as 

 in that of para. The demonstration concluded 

 about 12-30. The latex treated with " Purub " 

 had coagulated in an hour and the biscuits 

 were taken out of the basin to dry. It will be 

 treated in the ordinary way and will then be 

 tested with a view to finding out the real effects 

 of the " Purub " treatment. 



Mr. Bamber's Opinion. 

 Mr Bamber, asked by our representative for 

 his opinion on the morning s demonstration, 

 said the latex coagulated quickly, but nothing 

 else could be said until the rubber became dry 

 and was vulcanised. They themselves (meaning 

 the Government Scientific Department) were 

 carrying on heaps of experiments, but they 

 could not yet express an opinion on any one of 

 them. He was personally of opinion that 

 rubber should retain 9 or 10 per cent of mois- 

 ture, but whether it would increase the com- 

 mercial value of it depended on the manu- 

 facturers. Would they pay anything more for 

 it ? A large quantity of such rubber remained 

 unsold in London. 



The Treatment of Latex. 



After the experiments were set in train and 

 while waiting for the first definite results, Mr 

 Bamber took Mr Sandmann and party to a 

 section of old rubber where the Sinhalese tap- 

 pers were tapping some of the trees. What 

 attracted Mr Sandmann most was the bamboo 

 stand for holding the cup, but he could not 

 understand why it was that a piece of metal 

 was used for running the latex from the bark into 

 the cup and not a piece of bamboo or wood. He 

 is against the use of metal in any connection 

 with the receiving of the latex from the bark and 

 its treatment afterwards. The cups, he thinks, 

 should always be of porcelain or glass and the ves- 

 sels of enamel. It was also of great importance 

 that the latex should be kept cool when being 

 conveyed from the tree to the store. The sun's 

 rays had the effect of quickening the process of 

 decomposition of the latex. A wet cloth over 

 the vessel carrying it would prevent this and 

 also keep it cool. It was also of the greatest 

 importance that all the utensils used for the 

 preparation of the rubber should be kept ab- 

 solutely clean and to help towards this he 

 strongly recommended that only wooden uten- 

 sils, well-smoothed, should bo used. With 

 regard to sieves, in his opinion the best are 

 those made with horse hair. They should be of 

 two sizes, large and small, the former to be 

 placed on top and the latter below. Another 

 point was that the hand should not be brought in 

 contact with the latex which becomes acidulated 

 by such contact. 



The Rubber Trees in the Gardens, 



There are some hoary old giants among the 

 rubber trees in the Gardens, planted years and 

 years ago. In the early days the evils of close 

 planting were not realised. Some of the trees 



