290 H. G. SMITH. 



method, simple oxidation of the aldehyde group to carboxyl alone 

 taking place, this was proved by the analysis of the silver salt of 

 the acid. These results open up a very interesting line for research, 

 and further investigations will eventually be undertaken on this 

 subject. 



In a paper 1 read before this Society, August 2nd, 1899, p. 90, 

 it was shown that by natural oxidation of the oil of E. eugenoides 

 eucalyptol had been formed. This interesting fact has also been 

 noticed in the oil obtained from the "Red Box" of Rylstone, E. 

 ovalifolia, an oil which contains this aldehyde, but in which 

 phellandrene is also present. Eighteen months after distillation 

 and analysis, having occasion to again investigate the sample, it 

 was found that the oil had increased considerably in eucalyptol 

 content, and that the rectified oil had reduced its rotation in 

 100 mm. tube - 14*1° to - 12°. As phellandrene was originally 

 present in this oil, the lsevorotation was of course partly due to 

 that substance and partly to the presence of the aldehyde. 



By acting upon an alcoholic solution of the aldehyde with sodium 

 an odoriferous oil was obtained ; this is probably the alcohol 

 corresponding to the aldehyde. Subsequent investigation will 

 prove whether it is that substance. The oil of E. patentinervis 

 has already been shown to contain an aromatic alcohol (amyl ester 

 of eudesmic acid, loc. cit.) which could not satisfactorily be located; 

 the saponified oil had an odour identical with that of the oil 

 obtained by reduction of the aldehyde, and it is thus probable 

 that this alcohol occurs naturally in some Eucalyptus oils. 



Experimental. 

 Preparation of the pure aldehyde. — 1000 cc. of the crude oil of 

 Eucalyptus hemiphloia obtained at Belmore, near Sydney, in 

 September, was distilled. Constituents boiling below 190° C. were 

 removed, the remainder was agitated with acid sodium sulphite 

 and a crystalline mass thus obtained. After twenty-four hours this 

 was purified by well washing with ether-alcohol, drying the 



1 On the crystalline camphor of Eucalyptus oil (eudesmol) and natural 

 formation of eucalyptol (cineol). 



