ESSENTIAL OILS OF THE ANGOPHORAS. 119 



The finally rectified pineries of all the species agree very 

 closely in general characters, and this is well shown when 

 the results are tabulated : — 



Rotation o&d Sp. g. at 15° Ref. index. Sp. rota. [a]j> 



A. Baker i + 37°-5 0-8612 1-4658 at 18° + 43°-54 



A. melanoxylon + 37°'9 0-8615 1-4642 at 19° + 43°-99 



A. sp. +38°-l 0-8618 1-4655 at 18° +44°-21 



A. lanceolata + 33°-8 0-8661 1-4697 at 16° 



The higher specific gravity, refractive index, and lower 

 rotation of the pinene from A. lankeolata is accounted for 

 by the difficulty in sufficiently rectifying the small amount 

 of oil available. There seems, however, no reason to 

 suppose that the physical properties of the fully rectified 

 pinene from this species, would differ from that of the other 

 species. 



The essential oils from the oil-yielding species of Ango- 

 phora are thus seen to be very similar in chemical con- 

 stituents and in general characters. 



I am indebted to my colleague, Mr. R. T. Baker, f.l.s., 

 for the botanical information contained in this paper, and 

 for the authenticity of the material worked upon. 



