ELASTIC SUBSTANCE ON SHOOTS AND YOUNG LEAVES. 139 
was then but little different from the vulcanized mostly 
unaltered “‘rubber.”’ 
The Vegetable Wax.—The melting point of the powder 
was found to decrease as the leaves grew older. This 
is apparently due to the formation of a small amount of a 
vegetable wax, of somewhat low melting point. I have 
extracted this wax in much larger amount from other 
species of Hucalyptus in which the caoutchouc does not 
occur, and it is largely due to the presence of this wax, 
together with the white powdery material, that the 
pulverulent appearance of the young growth of certain 
Hucalypts, as H. cinerea, EH. pulverulenta, and allied 
species is due. 
The amount of vegetable wax (melting at 59—60° C.) 
obtained from 500 grams of the fresh material of HE. corym- 
bosa was 0°112 gram. equal to 0°0224%. It was extracted 
from the ether residue by boiling with petroleum ether (45 
— 50° C.) in which only the wax was soluble. It was finally 
purified from boiling alcohol in which it was fairly soluble, 
separating out again on cooling. Another determination 
was made on 800 grams of approximately the fifth and sixth 
leaves of the branchlets of EH. corymbosa. These were 
collected and treated at once with ether for five minutes. 
The ether was but slightly coloured; it was distilled to a 
small bulk when a considerable amount of the white powder 
had separated. This was filtered off and the filtrate 
evaporated to dryness; it weighed 1°2 grams. It was then 
boiled in petroleum ether in which alone the wax was 
soluble. When purified from boiling alcohol the wax 
weighed 0°0784 gram, equal to 0°01. The separated white 
powder, which when dry was like flour, weighed 5°5 grams, 
equal to 0°69%. The total extracted by ether from the 800 
grams of these leaves (the 5th and 6th) was 6°7 grams 
equal to 0°84%. Although almost 1% of this white powdery 
