AMYL ESTER OF EUDESMIC ACID IN EUCALYPTUS OILS. 75 



and the odour has but little resemblance to ordinary Eucalyptus 

 oil. It has a high specific gravity for an Eucalyptus oil, and it 

 was this peculiarity that first directed attention to it. On distil- 

 lation under atmospheric pressure 26 per cent, was obtained, 

 distilling between 156° and 164° C., 1 this was principally dextro- 

 pinene, proved by its boiling point, formation and character of its 

 nitrosochloride, its odour and other tests; only 12 per cent, was 

 obtained, distilling between 164° and 245° C. while 22 per cent, 

 distilled between 245° and 292° 0.; the remainder was poured 

 from the still and became semi-crystalline on cooling. The portion 

 adhering to the still was removed by ether. The crystalline 

 residue was reserved for further determination. 



The specific gravity of the crude oil at 15° C. was 0*956 



fraction 156° - 164° C. at 15° C. =0866 

 164°- 245° C. „ =0-8769 

 245°- 292° C. „ =0-9868 



Specific rotation, fraction 156° - 164° C. = [a] D + 27'13°. 

 Light did not pass with the crude oil. 



Phellandrene could not be detected in this oil, and eucalyptol 

 also appears to be quite absent. The principal constituents 

 present are dextropinene and the ester, with perhaps some poly- 

 merised terpenes. A small quantity of a new constituent is also 

 present, this has not yet been determined, but it has been isolated 

 from the oils of several other species of Eucalyptus in some of 

 which it occurs in fairly large quantities. 



Determination of Ester in the oil of E. aggregata. 



As it was evident that an acid had been separated at the high 

 temperature used during the distillation, determinations of the 

 ester in the original oil were made. The oil was boiled for half 

 an hour with a known quantity of alcoholic potash, standardised 

 by semi-normal sulphuric acid, a condenser being used in the 

 ordinary way. 



1 These temperatures have been corrected to the nearest whole degree. 



