253 



of sesquiterpene. The constituents in the oil of this Eucalypt differ greatly from 

 those in the oil of E. Bridgesiana, as can be seen by referring to that species. 



The crude oil had specific gravity at 15 C. -- 0-9049 ; rotation D 11-5 ; 

 refractive index at 20 = 1-4824, and was soluble in i volume 80 per cent, alcohol. 

 The saponification number for the esters and free acid was 7-3. 



On rectification, i per cent, distilled below 165 C. (corr.). Between 

 165-183, 70 per cent, distilled ; between 183-245, 2 per cent, came over, and 

 between 245-270, 20 per cent, distilled. The third fraction consisted largely of 

 the sesquiterpene. The fractions gave the following results : 

 First fraction, sp. gr. at 15 C. = 0-8886; rotation a D 21-1. 

 Third ,, ,, ,, = 0-9392; ,, not taken. 



The cineol, determined by the phosphoric acid method in the first fraction, 

 was 26 per cent., indicating about 18 per cent, in the crude oil (O.M.) 



This sample was stored in the dark, and in December, 1919, was again 

 analysed. The oil had altered somewhat during the nineteen years it had been 

 kept, and the phellandrene had suffered considerable loss in optical activity; it 

 had otherwise changed, so that only 52 per cent, distilled below 190 C. There 

 was apparently no increase in the amount of cineol. The crude oil and the 

 rectified portion gave the following results : 



Crude oil, sp. gr. at 15 C. = 0-9251; rotation a D - - 2; refractive index 



at 20 = 1-4825. 

 Rectified portion = 0-8947; rotation - - 6-4; refractive index 



at 20 : 1-4678. 



The cineol was determined by the resorcinol method in the rectified portion ; 

 when calculated for the crude oil, the result was 27 per cent. 



136. Eucalyptus microtheca. 



(F.v.M., in Journ. Linn. Soc., iii, 87.) 

 Coolabah or Tangoon. 



Systematic. A tree attaining a height of 80 feet, and -a stem diameter of 

 4 feet (H. K. Bennett). Bark rough, more or less dark or ashy-grey outside, 

 sometimes persistent, but occasionally smooth (F.v.M.). Leaves lanceolate, falcate, 

 always drying a light slate colour, oblique, measuring sometimes up to 8 or 

 9 inches in length and f inch in width, on a petiole of i inch or i inch long; 

 venation fairly prominent, intramarginal one not far removed from the edge. 

 Flowers mostly in terminal panicles. Calyx tube small, almost hemispherical ; 

 operculum conical, acuminate. 



Fruit. Small, hemispherical, on a slender pedicel; 

 rim thin; valves expanded and much 

 exserted and convex ; under 2 lines in dia- 

 meter. 

 These fruits stand alone as regards their shape. 



Habitat. From Narrabri to the deserts of the north-west of 

 New South Wales; South Australia; Queensland; 

 North Australia. 



