— 52 — 



contains chiefly pinene, but no eucalyptol or phellandrene. In the 

 second group containing eucalyptol, the midrib of the leaf is less 

 stout, and the marginal veins recede somewhat from the edge. The 

 veins of the leaves of the third group whose oil contains phellandrene, 

 are totally different: the midrib is very thin, and any feather- 

 like venation is absent. In view of the different composition of the 

 oils it is natural that they do not all possess the same medicinal value. 



Although the value of the eucalyptus oil produced annually in 

 Australia for medicinal purposes is j£ 40000 to £ 50000, it is 

 desirable to further develop the industry, and to take advantage of the 

 enormous masses of raw material which are now wasted. As a large 

 number of eucalypts are useless for economic purposes, those species 

 should be eradicated and other more useful species should be planted 

 instead. Two important points should also be observed, viz., firstly, 

 that oils produced from young shoots of every kind (frequently in a 

 good yield) have the same composition as oilsMrom old trees; and 

 secondly that the eucalypts are tenacious of life and after being cut down, 

 soon shoot forth again afresh. If, therefore, a large area were planted 

 with one particular species, and the young shoots were cut down by 

 machinery, and distilled, the expenses of the oil manufacture would 

 be merely nominal. Of the species which come chiefly under con- 

 sideration, the following should be mentioned: — 



Eucalyptus Macarthuri 1 ) , for the geraniol manufacture. The oil 

 contains at least 60 to 75%, in the form of geranyl acetate; in 

 inverse ratio to the ester -content is the content of free geraniol in 

 the oil. From young shoots 0,23% oil were obtained, the oil 

 being 2 °/ richer in ester than that of older trees. It should be 

 possible to obtain this oil easily in any quantity, but it remains to 

 be determined what is the most favourable time for collecting the 

 material in order to obtain the best yield of oil. 



1-Limonene and citral are found specially in the oil of Eucalyptus 

 Staigeriana" 2 ) , known in Queensland as "Lemon scented ironbark", 

 whose full-grown leaves yield 2,5 °/ oil. This oil might be employed 

 for many purposes instead of lemon oil (?) from which it differs parti- 

 cularly in the rotation. Smith mentions the following data for an 

 oil of E. Staigeriana : d 0,87; [«]p — 43>i°; citral i6°/ ; geranyl 

 acetate 8,3 °/ ; geraniol (?) 12,7%; not below 6o°/ limonene; pinene 

 and phellandrene were totally absent. The odour reminds of lemon 

 oil, and does not resemble that of ordinary eucalyptus oil. The citral - 

 content, which is higher than in lemon oil, is worthy of note, especially 

 if the object in view is the production of a terpeneless oil. 



*) Comp. Report April 1902, 38. 

 2 ) Comp. Report October 1906, 36. 



