PINENES OF THE OILS OF THE GENUS EUCALYPTUS. 195 



On the PINENES of the OILS of the GENUS 

 EUCALYPTUS.— Part I. 



By Henry G. Smith, f.c.s., Technological Museum, Sydney. 



[Read before the Royal Society of N. S. Wales, October 5, 1898.] 



The following paper deals with the investigation of both dextro- 

 rotatory and lsevorotatory pinenes found existing in the oils of 

 two new species of Eucalyptus growing in New South Wales. 1 



The occurrence of Eucalyptus oils consisting almost entirely of 

 the terpene pinene, is remarkable, and will assist to a very large 

 extent, in enabling us to trace the origin and formation of the 

 several constituents found existing in Eucalyptus oils. That a 

 connection does exist, running through the whole series, seems 

 probable, and it is only by carrying out investigations on oils of 

 undoubted material, that a correct scientific knowledge can be 

 obtained in this direction. 



The group of Eucalyptus trees to which these two species belong 

 is known vernacularly as the 'Stringy barks,' and both the species 

 form part of a chemical sub-group of the botanical class of the 

 Eucalypts known as the Renantherse, or those having kidney- 

 shaped anthers. 



We can derive no further help from the investigation of the 

 kinos of this group, because the exudations from all the Eucalypts 

 belonging to the Renantherse appear to be identical in compo- 

 sition; but the constituents of the oils indicate a sharp distinction. 

 The terpene composing the oils of these two species is principally 

 pinene; not a trace of phellandrene could be detected in them, 

 and so we are enabled to differentiate them from the oils obtained 

 from those trees belonging to the Renantherse, such as E. amyg- 



1 Vide E. T. Baker, f.l.s., on two New Eucalypts — Proc. Linn. Soc, 

 N.S.W., September 1898. 



