CEARA RUBBER 81 



Captain Cardozo's method of tapping is a 

 compromise between the conduit system, where- 

 by the latex is first collected and afterwards 

 coagulated, and the stabbing system, with which 

 the rubber is coagulated on the trees. He 

 extracts the rubber by stabbing, but collects 

 the latex in the liquid form and allows it to 

 coagulate afterwards in water, no coagulating 

 reagent being used. After coagulation the rubber 

 is rolled out in the form of flat, round biscuits. 

 It is beautiful clear, tough rubber with good 

 nerve. In 1906 he conducted some careful ex- 

 periments to ascertain the yield of the trees, 

 selecting for the purpose four six-year-old trees, 

 which he tapped for 9*2 days, from January 7th to 

 June 20th. The dimensions of the trees were as 

 follows : — 



^._., rj u. Surface Tapped. 



Girth. Height. Mean Superficial Area. 



Tree. 



Metres. Metres. Sq. Metres. 



No. 1 64 1-75 112 



No. 2 0-50 1-80 0-90 



No. 3 0-455 1-80 0-81 



No. 4 0-55 1-77 0-97 



Result. — Total dry rubber ... ... 1,161 grammes. 



Average per tree (10'15oz.)... 290 ,, 



Average per tree per dtem ... 2-55 ,, 



The second season he continued the experiment 

 with the same four trees, from December 25, 1906, 



6 



