280 
Test for viscosity according to Axelrot. — 10 grammes of the rubber 
were steeped and disolved in 300 cb. cm. henzol, and the period taken 
to run through of 100 cb. cm. of the solution taken by an Axelrot 
viscosimeter, whereby benzol, the running through period of which 
was taken as I for comparison. 
Singapore 1 
2 
Light Ceylon 
Dark „ 
Fine hard Para 
Congo 
... 21, 4 
... 21, 9 
... 35 , 6 
... 30 , 4 
... 59 , 8 
... 3L 6 
Breaking Strain and Stretch.— For this test the different kinds of 
rubber were always mixed in the same proportions, the mixtures 
vulcanized, and after being cut into rings of the’ same diameters, they 
were tested by a Schopper Apparatus for breaking strain and stretch. 
The results were as follows per square cm. 
Hard cured Para 
Singapore sample I 
„ ,» 2 
Light Ceylon Para 
Dark ,. 
Congo 
Breaking Strain. 
... 21, 0 Ks. 
■ • 32 , 5 
... 20, 0 „ 
... 14, 6 „ 
■ 17 , 3 „ 
... 14, 0 •„ 
Stretch. 
362, 5 °: 
350 , 0 
328, 75 / 
257 , 50 % 
366, 25 % 
347 , 50 % 
Adhesiveness. — A suitable mixture was coated on one side of a 
piece of cloth. The coated sides vulcanized together under pressure 
and tested for the amount of weight necessary to break strips 5 cm. 
broad. The results were 
Fine hard cured Para ... 
... 10, 
0 Ks. 
Singapore 1 ... 
... 9 , 
0 „ 
2 
... 9, 
5 „ * 
Light Ceylon ... 
... 5 , 
0 „ 
Dark 
... 5 , 
5 ,, 
Congo 
... 9 , 
0 „ 
The results are highly satisfactory for the samples sent us, and 
prove that the material of the Botanical Garden is quite equal to Fine 
hardcured Para. 
We cannot give at the present moment a definite opinion if the 
smoking of the rubber is a great advantage, as we have already men- 
tioned we are not sure if the materials used for comparison taken 
from the Hevea trees in Ceylon have been so carefully handled and 
the latex taken from trees of the same age. 
This latter point seems to us to be of much importance, as 
sample 1 from 12 year old trees gives a better result against sample 
2 from 8 year old trees, although it is specially remarked that this 
