Corresponding results have also been obtained with the oils of other 

 Eucalypts. 



The crude oil of E. cneorifolia, one of the " Malices " growing in South 

 Australia, appears to be always laevo-rotatory when prepared by ordinary methods 

 of distillation. This optical activity is also due to the presence of members of 

 this al deny die group. 



The oils of most Eucalypts growing as " Mallees " contain one or more of 

 these aldehydes, and these species are thus shown to be closely associated with 

 the members of the " Box " group. 



Eucalyptus Woollsiana, a species growing in the western portion of New 

 South Wales, also contains these aldehydes in quantity, and in working out this 

 species no less than six different distillations were made on material from various 

 localities where it grows plentifully. These results will be found recorded under 

 that species. 



The prepared composite aldehydes, separated by sodium carbonate from 

 the crystallised combination with sodium bisulphite, had the following specific 

 rotations for the following species : 



Eucalyptus salubris ... ... ... ... [a] D - - 90-45 



E. rostrata ... ... ... ... [a] D - - 73-94 



E. hemiphloia ... ... ... ... |VJ D - - 49-19 



So that no regularity in optical rotations is observed with the prepared 

 aldehydes from different Eucalypts. 



EXPERIMENTAL. 



940 c.c. of the crude oil of E. hemiphloia, containing some phellandrene, 

 distilled in March, 1920, was first agitated with a 5 per cent, solution of sodium 

 hydrate to remove the phenols. (From these phenols pure crystallised australol 

 was prepared.) It was afterwards distilled, and the portion boiling below 190 C. 

 separated. The remainder was repeatedly shaken with a 35 per cent, solution 

 of sodium bisulphite for six hours, the crystalline portion pumped off, purified 

 by washing with ether-alcohol, and decomposed by sodium carbonate. The 

 purified sodium sulphite compound weighed 49 grams, from which 24 c.c. of 

 aldehyde were obtained. This had specific gravity at 24 C. = 0-970 ; optical 

 rotation a D - - 20 C., and refractive index at 20 C. --- 1-5222. 



It was then distilled under reduced pressure, when 90 per cent, of the whole 

 boiled at 106-108 C. at 10 millimetres pressure. This portion had the 

 following constants : Specific gravity at 15 C. = 0-9767 ; rotation a D 20-1, and 

 refractive index at 20 1-5232. The hydrazone melted at 126-127 C., and 

 the semicarbazone at 210-211. This aldehyde evidently consisted largely of 

 cuminal, the optical activity being due to the aromadendral. 



In an attempt to separate the laevo-rotatory aromadendral all but 5 c.c. 

 were lost. This portion, however, gave constants even more closely approaching 

 those for cuminal, and the rotation was only a D 5. 



The aqueous portion separated from the crystalline compound was treated 

 with sodium carbonate solution, and the separated aldehyde extracted with ether. 

 In this way 5 c.c. of aldehyde were obtained, and although consisting largely of 

 aromadendral, yet it also contained cuminal, as is shown from the following 

 figures : It had specific gravity at 15 C. = 0-9703; rotation a D 28-5, and 

 refractive index at 20 1-5108. The semicarbazone melted at 204-205 C. 



The remaining aqueous solution was then decomposed by treating with 

 10 per cent, solution of sodium hydrate, and the aldehyde extracted with ether; 

 no less than 43 c.c. of aldehyde were obtained in this way. This had specific 



