207 



AN Investigation of the Essential Oil from 



EUCALYPTUS CNEORIFOUA, DC. 



(THE "Narrow Leaf Mallee" of Kangaroo Island) 



By Philip A. Berry, B.Sc. 

 (Communicated by Professor E. H. Rennie, D.Sc.) 



[Read August 10, 1922.] 



The principal constituent of this oil is cineol, while it is 

 well known that ter penes, aldehydes, and phenols are present. 

 The object of this investigation was to determine the average 

 cineol content, and the more precise nature and amount of 

 these other bodies with which the cineol is associated. 



The crude oil used in this investigation was obtained by 

 steam distillation of fresh leaves and twigs, collected at Cygnet 

 River, Kangaroo Island, in the beginning of January, 1920, 

 from leaf country which had been previously cut about three 

 years before. The yield of crude oil was 1 per cent. The 

 sample was an orange-lbrown colour and gave the follow- 

 ing constants: — Specific gravity at ^f ° C. =0'9102 ; specific 

 rotation, (a)D= -10-40; refractive index at 20° C. = 1'4707; 

 dispersion, 0*01029. The oil was soluble in 1'33 volumes ot 

 70 per cent, alcohol (by weight) at 20° C. The saponification 

 number for the esters and free acids was 70. 



Another sample of oil was distilled at Cygnet River, 

 about the middle of May, 1921, from the same species, in a 

 similar stage of growth, and under conditions similar to those 

 existing in the above distillation. This oil gave the following 

 constants: — Specific gravity at ^| ° C. = 0*9248; specific rota- 

 tion, (a)D = - 4-91° ; refractive index at 20° C. - 1*4670 ; 

 dispersion, 0*00979. The oil was soluble in 1*05 volumes of 

 70 per cent, alcohol at 20° C. 



This second distillation was performed to obtain an idea 

 of the difference between the oils distilled in the summer and 

 in the winter. The samples cannot be considered strictly 

 comparative, however, since, in the first case, the distillation 

 was continued until the leaf was exhausted of oil, while the 

 second sample was distilled under ordinary commercial con- 

 ditions, that is to say, until the amount of oil distilling was 

 very small in comparison to the water, and in consequence 

 contained less than the previous sample of the higher boiling 

 or less volatile constituents of the leaf. 



