426 



(3) EUCALYPTUS DIVES. 



A " BROAD-LEAF PEPPERMINT." 



(A species distilled in both New South Wales and Victoria.) 



This oil may be considered as the type of the extreme phellandrene 

 Eucalyptus oils, and although inclined to alter its physical characters by 

 age to a greater extent than those of the cmeol-pinene class, yet, when 

 freshly distilled, a relative constancy is noticeable, similarly with the oils of 

 the other species of Eucalyptus. The exceedingly high optical rotation is 

 chiefly due to the phellandrene, although the piperitone it contains is also 

 laevo-rotatory ; scarcely more than 5 per cent, of cineol is present at any time. 



Much of the oil of this species has been forwarded to Europe as the 

 product of E. amygdalina. Although regrettable, yet this misnaming was, to a 

 certain extent, excusable, because E. dives was classified for a long time as a 

 variety of E. amygdalina, and varietal names soon appear to lose their 

 identity. 



The oil of E. dives is considered the best of all essential oils for mineral' 

 separation by a flotation process, and considerable quantities have been used 

 in Australia for the separation of metallic sulphides. When it was decided to use 

 Eucalyptus oil for this purpose at Broken Hill, the first contract was for the 

 supply of the oil of this species. 



The tendency is now among some distillers in New South Wales to treat 

 the leaves of E. dives for several hours. This extended distillation naturally 

 results in the oil having a higher specific gravity, a less rotation, and to contain 

 a greater proportion of Piperitone than the product of, say, a three 01 four hours' 

 distillation; this is shown in the table above, but for flotation work both are of 

 equal value. For Piperitone production extended distillation gives better returns. 



Results illustrating this constancy in chemical characters with other 

 species have been tabulated, and will be found distributed throughout this work; 

 but after all this is only what might be expected, considering the extent of the 

 genus; and from our woik on the Tasmanian species it was shown that a large 

 proportion of those Eucalypts growing on the island were identical with trees of 

 the same species on the mainland. It is evident, therefore, that both the 

 botanical and chemical characters must have been stabilised long before 

 Tasmania was separated from Australia, and it is not difficult to accept similar 

 conclusions for practically the whole of the species in the genus. 



