119 



The following tabulated results obtained with the crude oils will show the 

 range of differences between the several samples : 



Considerable quantities of oil were commercially distilled from this species 

 at one time in the Towrang district of New South Wales, particularly by the 

 Australian Eucalyptus Oil Company, and we were thus able to test numerous 

 samples of this commercially distilled oil. It was not found to differ in consti- 

 tuents or general characters at any time, beyond what might be expected with 

 the oil from any one species. The specific gravity of the crude oil varies between 

 0-91 to 0-9225, the rectified oil being in agreement. The saponification number 

 of the esters and free acid in the crude oil usually ranges between 14 and 24. 

 As the trees are somewhat gregarious, with plenty of foliage, which yields a 

 fair percentage of a good oil, this species may be considered of value for 

 Eucalyptus oil distillation. 



The above oils were mixed together and stored in the dark, and in August, 

 1919, the sample was again analysed ; it had increased a little in specific 

 gravity, as was to be expected from the formation of the insoluble deposit, and 

 for the same reason had increased in cineol content. 86 per cent, distilled below 

 190 C. The crude oil and the rectified portion gave the following results : 



Crude oil, sp. gr. at 15 C. = 0-9238 ; rotation D + 4-0 ; refractive index 



at 20 : 1-4627. 

 Rectified portion = 0-9170 ; rotation a D + 4-5 ; refractive index 



at 20= 1-4604. 



The saponification number was 18-5 and after acetylation 55'4> equal to 

 10-5 per cent, of free alcohol, with a C IO H I8 O molecule. 



The cineol was determined by the resorcinol method in the rectified portion 

 and calculated for the crude oil; the result was 72 per cent. By the rapid 

 phosphoric acid method it was 60 per cent, when calculated for the crude 

 oil. Terpineol was detected in the rectified portion, which gave an alcohol value 

 equal to 8 per cent. 



The red colour of the cineol-pinene crude Eucalyptus oils is traceable to 

 the free acid attacking the iron of the stills, the iron reacting on the phenols, 

 consequently the colour may be removed by agitating with a solution of sodium 

 hydrate, fin commercial distillation of the leaves, copper still-heads were at 

 one time generally used, but it was soon found that copper fittings for this 

 purpose were unnecessary and objectionable, because the free acid in many of 

 the oils readily dissolved the copper, so that the crude oil became of a greenish 



