CRYSTALLINE CAMPHOR OF EUCALYPTUS OIL. 93 



From the results of the oil of E. eugenioides it is seen that the 

 formation of eucalyptol in the crude oils of this class does not 

 apparently take place without oxygen being present. How much 

 oxygen is necessary to bring about the maximum change is a 

 problem to be solved. 



In the paper on E. piperita (loc. cit.) eudesmol, eucalyptol 26 

 per cent., and phellandrene were shown to be present in the oil at 

 the time of distillation. It is possible in the oil of this species to 

 show the result of alteration in the formation of eucalyptol while 

 in the leaf. On 26th July 1898 (the end of our Australian winter) 

 a consignment of the leaves of E. piperita was received from 

 Currawang Creek, near Braid wood, N. S. Wales, the oil of which 

 on analysis contained no phellandrene, and the presence of an 

 extraordinarily large amount of eucalyptol was found, but no 

 eudesmol could be detected at that time. The oil on redistillation 

 gave a fraction boiling between 172° and 180° C, representing 

 75 per cent, of the crude oil, which fraction had a specific gravity 

 •915 at 15° 0., specific rotation [a] D 4-3*66° and contained 70 per 

 cent, eucalyptol. The rectified oil is almost colourless, exceedingly 

 brilliant in appearance and as rich in eucalyptol as any; it 

 resembles the oil of E. macrorhyncha and other first quality oils 

 of this class. In appearance, taste, odour and eucalyptol content, 

 the oils of this class of Eucalyptus, when obtained under correct 

 conditions are of superior quality, and it appears that by taking 

 advantage of known natural alterations in the constituents of these 

 oils, or by keeping the crude oils under certain conditions until 

 the maximum alteration has taken place, that we may govern the 

 formation of the constituents required, even if we do not succeed 

 eventually in bringing about the required alteration at once by 

 artificial means. 



From the consideration of the facts enumerated above, it appears 

 certain that the Eucalyptus camphor (eudesmol) is an intermediate 

 product in the natural formation of eucalyptol, and as such is not 

 to be expected to be present always in constant proportions. It 

 will be shown presently that the formula of eudesmol is C ]0 H 16 O 



