108 H. G. SMITH. 



Wales should be undertaken, so that the previous conclu- 

 sions might be strengthened, or otherwise. 



From the results now brought forward it is apparent that 

 the chemical changes which have become such a pronounced 

 feature with the oils of the Eucalypts, had scarcely com- 

 menced, if at all, in the oils of the Angophoras. It is 

 possible, however, to trace the origin of certain constituents 

 of Eucalyptus oils, and the dextro-rotatory pinene, the 

 geranyl-acetate, the geraniol, and the sesquiterpene, all 

 had their origin in the oils of the Angophoras, or perhaps 

 in some still older genus. It might be expected that certain 

 constituents would remain persistent in some directions if 

 the suggested relation between the genera was actual as 

 well as apparent. That this is so is shown by the numer- 

 ous pinene Eucalyptus oils, in which the dextro-rotatory 

 form is such a distinguishing feature, and by the many 

 Eucalyptus oils in which geranyl-acetate occurs, reaching 

 the maximum in that of Eucalyptus Macarthuri. 



The Angophoras as a class are not promising as oil yield- 

 ing plants, and from two species, A. cordifolia and sub- 

 velutina, no oil was obtained, while but traces can be 

 distilled from the leaves of A. intermedia. Some of the 

 other species, however, give fair yields of oil, more in fact 

 than is obtainable from several species of Eucalyptus. 



The following table gives the yields of oil distilled from 

 material cut as would be done for commercial oil distillation: 

 Angophora Baker i ... ... 31 per cent. 



,, melanoxylon . . . ... 0*19 „ 



„ sp 0-13 „ 



,, lanceolata (Sydney)... 0'013 ,, 



,, lanceolata (Warialda) 0'005 ,, 



„ intermedia ... . . traces 



,, subvelutina ... ... none 



,, cordifolia ... ... none 



