Essential Oil of Boronia plnnata. 15 



was derived from the flowers, and it may ]ye found not to occur in 

 rthe leaves. Although the fluorescence of the oil was apparently 

 -considerably diminished after agitation with dilute acid, yet it 

 was not entirely removed in this way. 



A considerable amount of work has been carried out on elemicin, 

 and iso-elemicin, by Semmler (Ber. 1908, 41, 1768, and other refer- 

 ences in the same volume), the material worked upon having been 

 • derived from Elemi oil. 



This is the first time elemicin has been detected in the oils of 

 .Australian plants. 



My thanks are due to Mr. F. W. Byrne, of the Chemical Depart- 

 :ment of the Museum, for assistance in this investigation. 



Experimental. 



The total yield of oil was equal to 0.383 per cent. The crude 

 oil, which was heavier than water, was of a light amber colour, 

 and had a mild aromatic odour, suggesting the presence of geraniol 

 and geranyl-acetate. It also had a slight fluorescence. When dis- 

 solved in absolute alcohol the secondary odour was pleasant, and it 

 appears that the oil of thisi species of Boronia will be found a use- 

 ful addition to the perfumery products of Australia. 

 The crude oil had : — 



Specific gravity at 15"C. = 1.0197. 

 Rotation aD= +3.8°. 

 Refractive index at 20°C = 1.5125. 

 Soluble in 1 vol. 70 per cent, alcohol (by weight). 

 The dextrorotation of the oil was due to the activity of a small 

 •quantity of pinene; this is shown later. 



The saponification number for the esters was determined both 

 by boiling and in the cold. 



(a) 1.5252 grams boiled for half-an-hour with alcoholic 

 potasb, required 0.0-306 gram KOH. S.N. = 20.2. 



(b) 1.528 grams treated witli alcoholic potash in tlie cold 

 with two hours' contact required 0.028 gram KOH. 

 S.N. = 18.3. 



This result is important, and, together with the odour, indi- 

 cates that the chief ester in the oil is geranyl-acetate, and that 

 it occurs to the extent of 6.4 per cent. 



That free geraniol was also present is suggested from the results 

 of acetylation. A portion of the crude oil was boiled with acetic 

 -anhydride and anhydrous sodium acetate in the usual way. 



