ESSENTIAL OIL OF LEPTOSPERMUM. 201 



The eudesmol appears to be present in minimum amount 

 at this time of the year, hence the high lasvo rotation and 

 low specific gravity of the May sample, and this was fortu- 

 nate as it enabled the sesquiterpenes to be the more readily 

 isolated. The principal constituents of the oil so far 

 determined are: — 



(1) The dextro rotatory bicyclic sesquiterpene alcohol — 

 eudesmol. 



(2 and 3) A mixture of two laevo rotatory sesquiterpenes 

 — eudesmene and aromadendrene. 



(4) P pinene. 



(5) « pinene. 



(6) Butyric and acetic acid esters of unknown alcohol, 

 as well as small amounts of alcohol of citronellol 

 odour (not geraniol or citronellol), also small amount 

 of both a solid and liquid phenol giving bright red 

 colouration with ferric chloride solution. Free acids, 

 aldehydes, ketones, phellandrene or limonene were 

 not detected. 



This oil is of considerable scientific interest as it is the 

 first record of the occurrence of the sesquiterpene eudes- 

 mene in nature, it having previously been obtained by 

 dehydration of the corresponding sesquiterpene alcohol. 



The presence of eudesmol in a Leptospermum has not 

 been noticed before, and its occurrence in quantity in such 

 is not without interest. This sesquiterpene alcohol has 

 only previously been recorded as being present in the oils 

 obtained from the Eucalypts. 1 



Nopinene (/3 pinene) has not previously been identified 

 as a definite constituent of Australian essential oils. The 

 oil of this Leptospermum is therefore, quite distinctive in 

 character and differs from that of any of its congeners so 

 far described. 



1 Baker and Smith," Research on the Eucalypts," 2nd Ed., p. 379. 



