92 H. G. SMITH. 



change. To test the accuracy of this surmise the oil No. 1 was 

 transferred to a large bottle which it only half filled, and by 

 occasionally shaking and removing the stopper, change soon com- 

 menced; so much so, that in two weeks the improvement in 

 eucalyptol could be readily detected, and on the expiration of one 

 month the oil was analysed with the following result : — 



On redistillation only a few drops came over below 167° C, by 

 170° 4 per cent, had been obtained; between that temperature 

 and 176-5° there distilled 70 per cent., and at 181° 88 per cent, 

 had come over. The oil distilling between 171° and 181° was 

 taken as one fraction. This was slightly yellowish in tint, but 

 brilliant in appearance and had a pleasant odour and taste. The 

 specific gravity of the rectified oil was -9102 at 15° 0., specific 

 rotation [a] D + 3*85° and it contained 58 per cent, of eucalyptol. 

 The crude oil had a specific gravity -9202 at 15° C. (an increase 

 in specific gravity on original determination), specific rotation 

 [a] D + 4*5° (a slight dextrorotatory increase) and contained at this 

 time (31-7*99) 55 per cent, of eucalyptol, an increase in eucalyptol 

 of nearly 24 per cent, from time of distillation from the leaves, 

 and an increase in eucalyptol of about 15 per cent, in one month 

 by alteration under the conditions described. It is evident that 

 the change is not yet completed in this oil, but more time could 

 not be given, and another analysis will be eventually made. It will 

 be observed that the other sample of the crude oil of E. eugenioides 

 contained 62*5 per cent, of eucalyptol, equal to about 65 per cent, 

 in the rectified portion, as the maximum of alteration. The maxi- 

 mum content of eucalyptol in the rectified portion of any Eucalyptus 

 oil appears to be about 70 per cent, (the fraction representing 

 about 80 to 85 per cent, of the whole), and although this amount 

 of eucalyptol is very rarely found to be present, yet it appears 

 that on natural alteration of oils like E. macrorhyncha, E. 

 eugenioides, etc., this standard may be reached by judicious 

 management. It may be that eventually we shall obtain complete 

 control of these results, and that the oil from prolific yielders 

 will be made to reach this standard. 



