146 A RESEARCH ON THE EUCALYPTS OF TASMANIA 



The Tasmanian eucalyptol-pinene oils in which phellan- 

 drene is absent, with the exception of those of E . globulus 

 and E . cordatn, are inclined to be of lighter gravity than 

 the " Mallee " oils; this is due to the presence of rather a 

 larger amount of pinene, and less high^boiling constituents 

 (which ire naturally heavy), but they mostly contain over 

 50 per cent, eucalyptol. The yield of oil would be, of 

 course, an important factor governing the commercial possi- 

 bility of these species for oil-distillation, and for that reason 

 the yields are given in a separate table. 



The oil of E. acervuJa was found to be of special interest 

 from a scientific point of view, and from it was isolated a 

 solid stearoptene belonging to the paraffin series. It is 

 announced in this paper as a new constituent in some 

 Eucalyptus oils. The oil of this species also contains a 

 considerable amount of geraniol and geranyl-acetate. 



The strong resemblance between the essential oil of E . 

 Gunnii and that of E . viminalis shows a close affinity exist- 

 ing between these two species. There is rather more phel- 

 landrene and less eucalyptol present in the oil of E . Gunnii 

 than in that of E . viminalis, otherwise the oils are similar. 

 The vernacular names, " Manna Gum " for E . viminalis 

 and *' Cider Tree " for E . Gunnii, indicate that a sweetish 

 sap is common to both trees, and this well-known fact also 

 points to a strong chemical relationship between them. 



Over 50 years ago. Hooker, in his '' Flora Tasmaniae," 

 pointed out from botanical evidence the close agreement 

 between these two Eucalypts, a suggestion which is now 

 confirmed by the results of this investigation. Although 

 showing such close affinity both are distinct species, and 

 although E. viminalis is a common tree in Australia, yet 

 so far as we are aware E. Gunnii does not occur on the 

 mainland. 



The peculiarities of the oils of the Tasmanian Eucalypts 

 will be found described under the several species, but we 

 cannot refrain from again pointing out the remarkable 

 agreement — in most instances — between the oil constituents 

 of the leaves and the botanical features of the plant. The 

 practical constancy of constituents in the oils of identical 

 species, wherever growing, is again shown most distinctly 

 by the results recorded in this paper, and much trouble 

 has been taken to secure authentic data to further support 

 the previous statements concerning this very useful aid 

 towards the correct determination of the several Eucalyptus 

 species. 



