110 R. T. BAKER AND H. G. SMITH. 



These results indicated the presence of an active terpene; 

 it was then again distilled, but the portion coming over 

 below 163° was small; this had, however, a rotation 14°*4 

 to the right, and the refractive index was reduced to 1*4706. 

 It is thus most probably that the small quantity of dextro- 

 rotatory terpene present in this oil is pinene. 



Cymene. — After removal of the terpene, as shown above, 

 the portion boiling between 174-178° was 7 cc. This had 

 a specific gravity at 15° 0. = 0*8623; and refractive index 

 at 19° = 1*4812. It was colourless, mobile, and had the 

 odour and appearance of cymene. It was oxidised — 2 cc. 

 at the time — by heating on the water bath with 12 grams 

 potassium permanganate and 330 grams water until reaction 

 was complete. The oxide was filtered off, and the clear 

 filtrate evaporated to dryness. The potassium salt was 

 then boiled out with alcohol, evaporated, the residue dis- 

 solved in water and acidified. The separated acid was 

 crystallised from alcohol. It melted at 155° C, and was 

 thus shown to be p-oxyisopropylbenzoic acid, proving the 

 prior presence of cymene in the oil. 



The principal constituent in the oil after the cineol, is 

 thus cymene. The residue in the still, boiling above 224° O. 

 was heated with alcoholic potash to saponify the remaining 

 esters, the oil separated and distilled. A portion came 

 over at the approximate temperature required for a sesqui- 

 terpene, but it was too small in amount to identify with 

 certainty. 



Explanation of Plate. 



1. Twig in flower. 



2. Portion of a leaf showing underside. 



3. Individual flower. 



4. Individual stamen. 



Figures 2, 3, 4, enlarged. 



