CRYSTALLINE CAMPHOR OF EUCALYPTUS OIL. 91 



this so-called "amygdalina oil" has been distilled, is now proved 

 by botanical characters and chemical evidence to be specifically 

 distinct from E. amygdalina of Labillardiere, and is Eucalyptus 

 dives of Schauer, which species was founded on immature trees). 



On redistilling this sample of the oil of E. eugenioides after 

 nearly two years, 5th July, 1899, 96 per cent, distilled below 

 182° C, the fraction being very rich in eucalyptol. The crude 

 oil which originally only contained 28'4 per cent, of eucalyptol, 

 now contained 62*5 per cent, eucalyptol, a marked increase. The 

 rotation had changed but little in this oil, being slightly more 

 dextrorotatory ([«] D + 5*5°) than when originally determined. 

 The specific gravity of the crude oil was -9171 @ 15° C, and of 

 the large fraction *9127 a slight increase on that of the crude oil. 1 



In the alteration of the other sample of the oil of E. eugenioides, 

 marked No. 1 in paper referred to, we are able to show the 

 necessity of a small quantity of oxygen to bring about the desired 

 change in the formation of eucalyptol. After the completion of 

 the original investigation on these oils, the crude oil remaining 

 was stored in the dark with other oils, and remained untouched for 

 nearly two years. A marked improvement in the eucalyptol con- 

 tent having taken place with the oil, No. 2 sample of E. eugenioides; 

 investigation of oil No. 1 was then made, with the result that the 

 same alteration had not then taken place with this oil as in that 

 of No. 2, it was but little richer in eucalyptol than when first 

 distilled, containing then under 40 per cent, eucalyptol. It 

 appeared only possible to account for this discrepancy by the fact 

 that the bottle containing No. 1 oil was quite full when put away, 

 whereas the bottle containing No. 2 oil was less than half full and 

 besides had been opened two or three times during the time. This 

 pointed to the fact that oxygen was necessary to bring about the 



1 The temperature at which the original specific gravity was given in 

 the paper is 22° C. This can be readily corrected, as by a determination 

 of a Eucalyptus oil at all temperatures between 10° C. and 22° C. it was 

 found that the increase below 15° C. and the decrease above that tem- 

 perature was almost identically '00075 for every degree of temperature, 

 water at 15° C. 



