90 H. G. SMI1H. 



Specific gravity, First fraction = -9124 @ 15° C. 

 „ „ Second „ = *9164 „ 



„ Third „ - -9188 „ 



Fourth „ = -9446 „ 



„ „ Crude oil = -9307 „ 



[a] D 4- 2 33° for first fraction and [a] D + 2-14° for second fraction. 

 Eucalyptol First fraction = 68*5 per cent. 

 ,, Second ,, = 71 "1 „ 



Originally the mean of several determinations of first and second 

 fractions gave 51 per cent, of eucalyptol. 



It will be seen that the first fraction is almost as rich in 

 eucalyptol as the second, and this is also found to be the case in 

 those oils that are exceedingly rich in eucalyptol at time of dis- 

 tillation, E. Smithii particularly. 



From these results it is apparent that by the alteration of the 

 high boiling constituents, marked changes have taken place. The 

 rotation has become more dextrorotatory, the specific gravity of 

 the lower boiling fractions has increased, the increase in eucalyptol 

 content is most marked, and the eudesmol has practically vanished. 



The investigation of the oil of E. eugenioides further emphasises 

 the specific alteration undergone by this class of oils on keeping 

 in the crude state under certain conditions. This oil is that 

 marked No. 2 of E. eugenioides in the paper previously referred 

 to (the Stringybark trees of N. S. Wales). Unfortunately a full 

 investigation was not made of that particular oil at the time, but 

 enough data are given to determine the direction of change. The 

 same absorption of oxygen was apparent as in the oil of E. macro- 

 rhyncha and the alteration of the constituents was in the same 

 direction as found in that oil. No eudesmol was originally 

 detected in this oil, but there appears little doubt but that it 

 should be found, if carefully sought for, as it exists in other oils 

 of the class to which this species belongs, viz.: — E. macrorhyncha, 

 E. piperita, and E. amygdalina (not the species from which 

 much of the supposed "amygdalina oil " that has been sent to 

 Europe under that name was obtained, as the tree from which 



