■62 HENEY G. SMITH. 



hours contact, using alcoholic potash. This method of cold 

 saponification is important, as the reaction is complete, 

 and the quantitative results certain. Duplicate and tripli- 

 cate determinations have been found always to agree 

 within the errors of experiment. The results, so far, show 

 that the minimum standard of 60 per cent, of ester might 

 he insisted upon, for the oil of this species, at any time of 

 the year. The oil of this Eucalyptus does not appear to 

 contain phellandrene at any time, so that its detection 

 would indicate sophistication with the cheaper phellandrene 

 oils. Undoubted samples of the oil of E. Macarthuri do 

 not contain Eucalyptol, so that the detection of this con- 

 stituent would also cause suspicion. The most valuable 

 constituent in this oil is, of course, geranyl-acetate, so 

 that any admixture with inferior oils would at once diminish 

 its value ; but the detection of adulteration is exceedingly 

 easy, as not only would such a mixture be at once detected, 

 but the group of Eucalypts from which the added oil had 

 been derived could also be determined. 



In Messrs. Schimmel & Go's price list for January 1902, 

 the oil of Eucalyptus Macarthuri, containing 80 per cent, 

 of geranyl-acetate, is quoted at twenty-four shillings per 

 pound. The oil of this species does not contain this amount 

 of ester at any time of the year, so that if this standard is 

 maintained it would be necessary to acetylise the free 

 geraniol occurring in the oil, or else to add the necessary 

 amount of geranyl-acetate to it. Geranyl-acetate is quoted 

 in the price list above referred to at forty shillings per 

 pound. 



During the greater portion of the year the oil of E. 

 Macarthuri, after acetylising, would show the presence of 

 80 per cent, of ester, and often a little over that amount, 

 the extra ester having been obtained from the free alcohol 

 present in the original oil. It is perhaps remarkable, that 



