Mi I 



A chemical examination of each of the two specimens gave the 

 following results : — 



Rubber from young trees (4 yrs. old) 

 Rubber from old trees 



The purified caoutchouc from the rubber of the young trees was 



very soft and sticky, whereas that furnished by the rubber from the 



older trees exhibited very satisfactory physical properties. 



These analyses amply confirm the opinion based upon the appear- 

 ance of the samples and prove that the rubber prepared from the latex 

 of the young trees of ''astilloa elastica is a very inferior product, 

 consisting largely of resin. The results agree with previous analyses 

 recorded by different investigators who have invariably fouud that the 

 amount of resin in the latex of Castilloa elastica is very large in the 

 youn"- trees but gradually diminishes with age. until after the eighth 

 year or so the tree yields rubber of good quality. Practical experiments 

 in the cultivation of Castilloa elastica fully support this conclusion. 

 The ao-e of the " old trees " under notice was not stated but the amount 

 of resin present in the rubber, viz : 15*8 per cent., is much greater 

 than is permissible in rubber of good quality. 



II. — TWO SAMPLES OK FUNTUMIA RUBBER. 



Two small samples of rubber derived respectively from Funtumia 

 africana and Fimtumia elastica under cultivation in Trinidad were 

 forwarded to the Imperial Institute by the Superintendent of the Royal 

 Botanic Gardens at the instance of the Government of Trinidad. In 

 his letter, dated July 29th. 1902. Mr. Hart stated that the specimen- 

 were obtained from seedlings of the two species, three years old and 

 with stems about 3 inches in diameter, and that the latex was coagu- 

 lated by the addition of alcohol. It was also mentioned that according 

 to reports from West Africa. Funtumia africana produces rubber of 

 inferior quality whereas Funtumia elastica yields an excellent product, 

 and it was therefore desired to ascertain whether this would be the 

 case when the plants were grown in Trinidad. The physical character 

 of the two specimens certainly tended to support the view that there 

 is a great difference in the quality of the rubber yielded by the 

 two species. 



(1.) KUBBKK FROM FUNTUMIA AFRICANA, si AIM. 

 The specimen was forwarded between watch glasses. It was a 

 very soft, sticky mass which adhered t<> the fingers and pulled out 

 in Ion"- fine threads : it had a brownish colour externally but was 

 whitish within. 



(2.) Rubber from Funtumia elastica. stapf. 

 This was a small piece of soft and sticky rubber of dark brown 

 colour; it exhibited good elasticity and fair tenacity. It was much 

 superior in physical characters to the preceding specimen. 



The following results were obtained on analysis : — 



CALCULATED ON THE DRY MATERIAL FOR COMPARISON. 



Moisture. Caoutchouc Resin. Dirt. 



(1.) Funtumia africana 207 39'3 60*0 »"7 



(2.) Funtumia elastica 15 - 1 SO "4 15 3 4 3 



It will be seen from these figures that the sample of rubber from 

 Funtumia africana is greatly inferior to that from Funtwnin elastica 



