ESSENTIAL OILS OF THE ANGOPHORAS. 107 



Eucalypts," 1902, p. 16. The leaves of A. lanceolata were 

 more easily obtainable, and for this reason were used for 

 the purpose. It was desirable, at that time, to determine 

 whether the oil from this group of Myrtaceous trees was 

 in agreement with that distilled from certain species of 

 Eucalyptus. It had been found previously that the vena- 

 tion of the leaves of some Eucalypts, particularly those of 

 the "Bloodwood " group, indicated the presence of pinene 

 in their oils. 1 The terpene phellandrene is not a constituent 

 of Eucalyptus oils from species so early in the evolution 

 of the genus, and those Eucalypts yielding phellandrene 

 bearing oils have quite a distinct leaf venation. 



The venation of the mature lanceolate leaves of the 

 Angophoras is similar to that of the " Bloodwood" group 

 of Eucalypts, and the oils should, therefore, consist largely 

 of pinene. Although the yield of oil from A. lanceolata is 

 very small, yet sufficient was obtained to furnish the 

 evidence required, and it was thus possible to show a 

 distinct chemical connection, through their oils, between 

 the Angophoras and the Eucalypts at the older end of that 

 genus. The evidences in other directions, which have 

 accumulated since that time, all tend to support the con- 

 clusions then advanced, and it may now be stated with some 

 confidence that the Angophoras are very closely in agree- 

 ment with the Eucalypts, and that Angophora is the older 

 genus. Besides the evidence derived from the investigation 

 of the oils, this close relation is further emphasised by the 

 study of the kinos, or astringent exudations; and the 

 presence of the caoutchouc on the young leaves of certain 

 species of Angophora and Eucalyptus is also a feature of 

 some value in this connection. 



It was desirable, therefore, that an investigation of the 

 oils of all the known species of Angophora in New South 



1 This Journal, Vol. xxxv, p. 116, 1 901. 



