/ 



Gums, Resin*, 364 [New. 190(5 



Mr. Devitt :— In regard to the question of sampling, planters rather seem 

 to have an idea that we make something ont of the samples, but I may say that 

 every pound of rubber that is taken is accounted for. If the buyer wants the 

 sample he pays for it. If not, it is returned to the bulk before being weighed over. 



Mr. Zacharias :— Having brought over some cases from Singapore, we have 

 got some good examples of what rubber looks like when it arrives in London. 

 If you look at our rubber, you will find that the sheets are all glued together ; 

 but there is no tackiness whatever. In fact, the judges were so well pleased with 

 some of them that they awarded them Honourable Mention. They were very thin 

 sheets, and by the time they arrived, although they had filled the packing cases, 

 they had contracted into a small block. There is one point I should like to have 

 an answer to, and that is relating to block rubber. All cultivated rubber in any 

 other form when pulled will never go back to the same place where you started. 

 It always becomes longer by being stretched, whereas I understand fine Para 

 never does that but it comes back almost entirely. I noticed that block rubber 

 stretched in the same way will go back to the same size. I have noticed that in 

 the Lanadron blocks which won the gold medal and also in rambong blocks. I 

 should like to know if my impression is correct, if that would show that the pressing 

 of the crepe adds strength ? 



Mr. Devitt :— I noticed that this morning. I tried some of the strips cut 

 from the blocks and I was impressed at their resiliency. On the other hand, Mr. 

 Wright showed me biscuits from 29| years-old trees, and they went back to the 1 

 same size as before after being pulled. 



Mr. Herbert Wright :— They were J of-an-inch in thickness. 



Mr. Devitt :— Yes, that is so. 

 relations between the physical properties and chemical composition 



op RUBBER. 



Mr. Herbert Wright :— I should like to bring forward one matter to which 

 Mr. Devitt has referred. That is the relationship between the physical properties 

 and chemical composition of the different kinds of rubber. In his recent speech 

 at the British Association Prof. Dunstan said that the physical properties of raw 

 rubber are to be correlated with the chemical composition of the substance itself. To 

 some extent we can say that that logically applies to the different rubbers, it we 

 regard the rubber from different species such as Para, castilloa, landolphia, ceara, &c, 

 and again we can say it holds good if we compare rubbers from castilloa trees 

 of different ages. As has been pointed out, three-year-old castilloa trees possessed 

 55 percent, of resin and 8 year-old trees possessed only 7 per cent. That statement 

 of Professor Dunstan is, therefore, apparently applicable to the rubber obtained 

 from castilloa trees of different ages and in a compartive sense to rubber obtained 

 from different species ; but when we come to consider our own rubber, Para, it 

 is rather different to see a common agreement. I took the judges over some 

 samples of rubber in the laboratory at the Experiment Station. Some 'of it was 

 from trees two years old and others from 3, 5, 7, 10, 11 and 29£ years old, and the 

 difference in the physical property was manifest. The ease with which some of 

 the young rubber was torn up was remarkable ; whei has been pointed out, 



the rubber from the 29^ year-old trees, even our youthful judges were not strong 

 enough to break. We were lucky enough to get a snapshot of them with the 

 ordinary-sized biscuit stretched out to 2 ft. 9 in. between them. The judges have 

 divided the biscuits between them, and are taking them back to England. (Hear, 

 hear.) Therefore we have in Para rubber a definite and conclusive difference in 



