487 



26. Eucalyptus cosmophylla, F. v. M. 



(Trans. Vict. Inst,, 32). 



"Scrub Gum." 



So far as known, this Eucalyptus is endemic to South 

 Australia. Though generally a medium tree, yet it occasion- 

 ally attains large dimensions, according to Mr. Gill. It- 

 extends to Kangaroo Island. 



Essential Oil. 



Leaves with terminal branchlets of this species for distil- 

 lation were received from the Conservator of Forests, 

 Mr. Walter Gill. The material was collected in the month of 

 December. The average yield of oil was 0*62 per cent. The 

 crude oil was light orange-brown in colour, with an odour 

 indicative of an oil belonging to the cineol-pinene group, with 

 a secondary odour suggestive of the aldehyde aromaclendral. 

 The presence of volatile aldehydes was particularly marked. 

 The slight laevorotation of the crude oil is largely due to the 

 aromadendral, although the pinene is als'o laevorotatory to a 

 small extent. Phellandrene was absent. This left rotation 

 is unusual with oils of this class, as in most cases the pinene 

 shows a predominant dextrorotation. The cineol content is 

 only fair, and the oil does not contain constituents having 

 special characters. The species has, therefore, little value as 

 an oil-producing tree. 



The crude oil had specific gravity at 15° C.=0'9108; 

 rotation, a D — 3*2°; refractive index at 20° = 1'4659, and was 

 soluble in 7 volumes 70 per cent, alcohol. The saponification 

 number for the esters and free acids was 5'6. 



On rectification a few drops of acid water, together with 

 some aldehydes, came over below 167° (corr.). Between 

 167-172°, 9 per cent, distilled; between 172-198°, 75 per 

 cent, came over, and between 198-270° 11 per cent, distilled. 

 These fractions gave the following: — 





Sp. gr. at 15° C. 



.Rotation n-Q 



Ref. index at 20°. 



First fraction 

 Second fraction 

 Third fraction 



0-8909 



0-9065 

 0-9296 



-2*6° 



-3-0° 

 -3-3° 



1-4612 

 1-4628 

 1-4827 



The cineol was determined by the resorcinol method in 

 the rectified portion ; the result showed the presence of 50 



