ESSENTIAL OIL FROM BARK OF EUCALYPTUS MACARTHURI. 179 



— eudesmol — , which is a constant constituent in the leaf 

 •oil, has not been noticed in the bark oil. 



A determination of the ester by cold saponification in 

 alcoholic potash with two hours' contact, gave the follow- 

 ing result: — 1*107 gram oil required 0*1876 gram KOH, 

 giving as saponification number 169*5, equal to 59*3 per cent, 

 .geranyl-acetate. 



A portion of the oil was acetylated by boiling with acetic 

 anhydride and sodium acetate in the usual way. 



1*028 gram of the acetylated oil by cold saponification 

 required 0*2044 gram KOH, giving as saponification number 

 1198*8, equal to 69*6 per cent, of ester. The saponification 

 number was thus increased by 29*3, corresponding to 10*25 

 per cent, ester derived from the free geraniol in the oil. 

 * * * * 



A sample of crude oil was distilled in October 1915, at 

 IVingello, by Mr. J. Quigg from the bark of this species, 

 and forwarded to the Technological Museum. This oil was 

 light amber in colour and had a good odour. It contained 

 a larger amount of ester than did the oil distilled at the 

 Museum, and had the following characters: — 



Specific gravity at 15° O. = 0*9099 



Optical rotation a D = + 1*4° 



Refractive index at 20° = 1*4648 



Soluble in 1*2 volumes 70 per cent, alcohol. 



The saponification number for the ester by cold saponi- 

 fication with two hours' contact was 195, equal to 68*2 

 per cent, geranyl-acetate. 



The saponification number of the acetylated oil by cold 

 saponification was 224, equal to 78*4 per cent, of ester, an 

 increase in the saponification number of 29, representing 

 10*2 per cent, of ester formed with the free geraniol in the 

 oil. 



