286 EUCALYPTUS. 



A mere glance at the above table will show how very 

 different in color, specific gravities, and amounts of yield 

 the different varieties of Eucalyptus are and the character- 

 istic odors are as diversified as their other points, indeed 

 they are so different that it might be possible to identify 

 the variety by its oil. 



The variety Gunnii yielded no oil, but during distilla- 

 tion, an non-condensible vapor came over, which had a tem- 

 perature of 58 degres, F., and filled the room with the char- 

 acteristic odor of bitter almonds. 



Of all the twenty-six varieties distilled, but seven or 

 eight seem to yield sufficient oil to pay for extracting and 

 the maufacturer should see to it that other varieties of 

 leaves are not allowed to be mixed with these varieties 

 when buying. Indeed, only one variety of leaves should 

 be placed in the still at one time ; this rule should be 

 carried out until such time as the value of each variety of 

 oil could be determined. 



Re=distillation. 



With the single exception of citriodora oil, it is neces- 

 sary to re-distill Eucalyptus oils and they all carry some 

 trace of their original color with them. If, however, they 

 are re-distilled with from three to four times their weight 

 of water, always using the water of distillation from first 

 distillation and one part in forty of caustic potash of the 

 best quality, such as Babbit's, a water white oil can be 

 obtained. 



On partial distillation of the Eucalyptus globulus about 

 4 per cent, comes over at a temperature below 170 degrees 

 C., from 57 to 60 per cent, comes over between 175 and 180 



