82 PROCEEDINGS OF SECTION B. 



that only those species can be utilised which produce the richest 

 Eucalyptol oils and yield them in greatest abundance. The com- 

 petition amongst suppliers has, during recent years, become very 

 keen, and consequently the price has been reduced to the lowest, 

 commensurate with a sufficient profit on working expenses. 



The first Eucalyptus tree supplying a Eucalyptol oil com- 

 mercially was E. globulus, and the good favour that this oil then 

 obtained has remained with it even up to the present time. This 

 appreciation is. perhaps, more largely due to the name than to any 

 intrinsic merit the oil may have above that of other species in the 

 same class. The " Mallee " Eucalyptol oils, such as E. dumosa, 

 and E. oleosa, then came into use, because the yield was greater 

 than with E. globulus, and as these species grow as shrubs the 

 material was easier to collect, and consequently the oil could be 

 produced at a cheaper rate. Many of the " Mallee " oils, although 

 rich in Eucalyptol, often contain a small amount of the aromatic 

 aldehyde aromadendral, which constituent appears to be absent 

 in the oil of E. globulus, E. Smithii and other similar species, and 

 consequently the odour of the various eucalyptol oils is not always 

 identical. E. polybractea, another " mallee," yields one of the 

 richest Eucalyptol oils, and in great quantity, but it also contains a 

 small amount of aromadendral. This constituent, however, can be 

 largely left in the leaf by a proper system of distillation, the product 

 then being, when rectified, one of the very best of the Eucalyptol 

 class of oils. As this is the principal species occurring over many 

 square miles of country in the Wyalong district of this State, there is 

 available at once what may be considered a permanent plantation. 

 The reason this species has not yet been more systematically worked 

 is that it grows far away from the coast, and the cost of transit and 

 other incidental expenses have so far operated adversely. 



Probabl}/ the Eucalyptus species yielding the best and richest 

 Eucalyptol oil yet known is E. Smithii. The yield is great, and such 

 objectionable constituents as the aldehydes, esters, sesquiterpenes, 

 etc., are at a minimum ; the rectified oil consists almost entirely of 

 Eucalyptol, the remainder being largely pinene. E. Smithii has, since 

 the discovery of the value of its oil, been largely worked, but the 

 species usually grows as a big tree, and mostly in mountainous 

 country, consequently the material is quite as difficult to collect as 

 is that of E. globulus, but it yields twice the amount of oil obtainable 

 from the latter species. If E. Smithii were systematically culti- 

 vated for its oil, an article could be produced, which as a pharma- 

 ceutical Eucalyptus oil, and as a source of Eucalyptol itself, would 

 be superior, perhaps, to that obtainable from any other species, as it 

 could then be supplied so cheaply. When the time arrives for 

 Eucalyptus species to be systematically cultivated in Australia for 

 their economic products, then E. Smithii would probably answer 

 all demands for a Eucalyptol oil better than any other Eucalypt. 

 Other species yielding Eucalyptol oils in great quantity are E. 

 cordata of Tasmania, and E. pulverulenta of this State. These two 

 oils, however, contain rather a large amount of ester, and the lower 



