164 



H. G. SMITH. 



distilled in the laboratory, and the residue distilled directly? 

 only five ounces of the 40 lbs. did not distil below 190° CL 

 equal to 0*78 per cent. 



The constituents present in the oil, besides pinene and 

 cineol, are a phenol, a small amount of volatile aldehydes* 

 dextrorotatory eudesmol melting at 79° O., a solid paraffin 

 melting at 64° O., 1 a small quantity of esters, partly a low- 

 boiling one, probably butyl-butyrate, 2 and a small amount 

 of sesquiterpene. Neither phellandrene, piperitone nor 

 aromadendral have so far been detected in the oil of this 

 species. 



The ready way in which the chief volatile aldehyde 

 polymerises or alters to a compound with a sweet-briar- 

 like scent soon renders the oil pleasant both in odour and 

 taste. The volatile cough-producing aldehydes which are 

 often so objectionable in the oils of many species yielding a 

 cineol-pinene product, seem to be largely absent in the oil 

 of E. Smithii. The identity of the chief volatile aldehyde 

 in the oil of this species has not yet been accurately deter- 

 mined, but it seems to differ from those usually present in 

 the oils of the members of the "Gum" group, such as E+ 

 globulus, E. goniocalyx, etc., and also in those derived from 

 some of the "Mallees." 



The colour of the rectified oil of E. Smithii, when freshly 

 distilled, is slightly yellow, as are most of the richer cineol 

 oils which do not contain phellandrene. This yellowish 

 tint is apparently due to quinone influence, and is traceable 

 to the particular phenol present in the oils of this group of 

 Eucalypts. 3 Through the influence of light the colour 

 disappears, the oil eventually becoming colourless. 



1 H. G. Smith, this Journal, Vol. xlvii, p. 95, 1913. 



2 H. G. Smith, this Journal, Vol. xlviii, p. 474, 1914. 



8 E. Eobinson and H. G. Smith, this Journal, Vol. xlviii, p. 518,1915. 



