EUCALYPTUS AUSTRALIANA AND ITS ESSENTIAL OIL. 519 



accomplished, as the boiling points of the two substances 

 are too closely in agreement, so that it must be to the 

 modification of the process of steam distillation that 

 improved results may be looked for from this species, in 

 districts where the oil contains more phellandrene and 

 consequently less cineol than does that from trees growing 

 in the Nerrigundah and Yourie districts. 



It is perhaps due to climatic influences, in addition to 

 those of altitude and soil conditions, that the increased 

 cineol content in the oil of the Nerrigundah trees has 

 become sufficiently distinct to be noticeable as a general 

 rule. In our work on the Eucalypts, p. 275, we drew 

 attention to some remarkable features shown by the oil of 

 this species, particularly that of solubility in 70% alcohol, 

 a result which placed the species in that class yielding 

 Eucalyptus oils richest in cineol, thus practically predicting 

 the present results. This high solubility of the phellandrene 

 bearing oil of this Eucalyptus is evidently largely due to 

 the presence of an, at present, undetermined alcohol. This 

 is suggested from the increased saponification numbers of 

 the acetylated higher boiling fractions, and is also shown 

 from the results with the Nerrigundah second hour oil. 

 For comparison with this, the results of the second fraction 

 of the oil of this species, distilled for us by Mr. Douglas, at 

 Moss Vale in November, 1915, are given. This fraction 

 boiled between 193° and 210° C. 



Saponification number for esters in second hour oil =11*4 

 „ „ for same fraction acetylated = 95*1 



„ „ for esters, second fraction, 



Moss Vale oil = ll'l 

 „ „ for same fraction acetylated = 94*4 



The changes in constituents which can thus be observed 

 seem to be between the cineol and the phellandrene. Fur- 

 ther research may decide in what manner this has been 

 brought about. 



