2Q4 



can be varied with the aperture of the cylinder and the fineness 

 of the sand. When the whole of the sand has passed into the 

 hanging receiver, the pointers are adjusted to the marks previously 

 made and a reading taken which according to the elasticity of m 

 rubber being tested may be 100 per cent or more of the original 

 measurement vis., 5.0 centimetres. 



The stop-cock at the bottom of the hanging receiver is then 

 opened and the sand is allowed to flow out the strain being thus 

 as released as gradually it was imposed. 



When the vessel is empty it is removed and after two minutes 

 the pointers are again adjusted and a third reading taken which 

 according to the resilience of the rubber approximates to 5 centi- 

 metres the original length. 



In a series of tests made from pieces of biscuit rubber pieces 

 taken from different places of the same biscuit gave practically 

 exact results, while samples of biscuits of from plantations of 

 different age varied considerably. In these preliminary tests of 

 the efficiency of the apparatus the results showed that the figures 

 obtained were reliable, and though I myself or others may be able 

 to improve or simplify the apparatus, yet as a practical curing 

 house and office that it should be of use in arriving at a fixed 

 method of judging the qualities of rubber either plantation or 

 Brazilian para. 



The use of this apparatus on various qualities of rubber and 

 under varying conditions has given me useful data in relation to 

 the physical qualities of plantation rubbers. The length of time 

 during which extension takes place when a weight is gradual y 

 imposed, and after the weight has all been placed and the leng n 

 of time for recovering back to approximately the original dune* 

 sions show interesting variations in different qualities of rubber. 



It is the physical qualities of resilience and elasticity that are 

 01 value in India rubber and the chemical compositions are 07 

 D on , reSt m A S ° far as the y correlated with these phys^ 

 properties. A physical test is therefore the most import ant an 

 this is recogn.sed by the most careful manufacturers who test » 

 th e dr e r n u C bber ter ^ ^ m ™ ufactured ^ mixed ^ 

 Me T ssrs a ffr tUS f described " as made from my drawing by 

 Far E as f A ' R f - and TATLOCK, but owing to my absent ^ 

 to m 1 / ta ' n . ,m P r °vements and modifications which occ 

 to me after designing the plant of the machine could not be maa 

 J. B. CARRUTHERS. 



A PARASITIC FUNGUS ON TAPIOCA- 



Botanic'r 11 °J thlS year ' Mr ' SNODGRASS brought to the office j > 

 botanic Gardens from Malacca a number of leaves of ia r 



