122 PROCEEDINGS OP SECTION B. 



as a big tree, consequently it might be expected to show considerable 

 rapidity of growth. As it is somewhat sparsely distributed in its native 

 habitat, it would be necessary to cultivate it so as to enable the best 

 returns to be obtained. The young growth usually yields a larger 

 amount of oil, and this is even richer in the required constituents than 

 that from the mature leaves. It thus appears that by systematically 

 cultivating this species in plantations, these particular odoriferous 

 constituents could be largely supplied from the Australian eucalypts. 



There is yet another eucalyptus which appears to me to have 

 considerable prospective value — that is. Eucalyptus Staigeriana, also 

 a Queensland tree. About one-sixth of the oil distilled from the leaves 

 of this tree is the aldehyde citral, most of the remainder being limonene. 

 It should eventually come into use as a lemon-flavouring agent, if 

 properly rectified and prepared. The constitution of the oil shows it 

 to have a somewhat close resemblance to lemon oil, and, as the yield is 

 very large, the cultivation of this species is worthy of the most serious 

 consideration. 



The propagation of eucalyptus species away from their native 

 habitat opens up consideration of feasibility ; and the question 

 naturally arises whether the conditions of the proposed new location 

 yyould be suitable. Moderate variation in climate appears to have less 

 influence upon the successful growth of eucalyptus species than has 

 the composition of the soil. Many species occur within a narrow 

 range of altitude, yet on the same elevation some choose well-defined 

 geological formations, and do not care to grow on those of a different 

 nature. In the neighbourhood of Sydney, certain species are found 

 plentifully distributed on the Hawkesbury sandstone formation, but 

 not to any extent on the overlying Wianamatta shales ; whilst some 

 which flourish on the shales are seldom found growing on the neigh- 

 bouring sandstones ; evidently this distribution is influenced by the 

 available food supply. This is not an uncommon feature with eucalyp- 

 tus species, so that the problem of successful cultivation resolves 

 itself into a chemical question, and one that might be largely worked 

 out in the chemical laboratory. Work undertaken in this direction 

 should render considerable assistance, not only in the propagation of 

 species for oil production, but in the larger problem of forest distribution. 

 The chemical products of the several species of eucalyptus are so diverse 

 that conditions tending to complete success in one instance could hardly 

 be expected to apply equally well in another. What those conditions 

 are can, of course, be best determined by systematic scientific research. 



The commercial possibilities of the barks of certain species of 

 eucalyptus for tannin purposes have recently been exemplified by the 

 use in large quantities of that of the " mallet " of Western Australia 

 (Eucalyptus occidentalis.) 



