208 M. B. WELCH AND A. R. PENFOLD. 



bisulphite compound was then separated, washed with 

 alcohol-ether, dried on a porous plate, and decomposed with 

 caustic soda solution, when the liberated ketone was blown 

 over in a current of steam. Two such preparations pos- 

 sessed the following characteristics: — 



No. 1 No. 2 



Specific gravity 20° O. 0*9157 ... 0*9158 



Optical rotation -65*3° ... -66*22° 



Refractive index, 23° C. 1*4493 16° C. 1*4520 

 Boiling point at 10 mm. 79 - 80° C. ... 79 - 80° C. 



Tribromide, melting point 125-126 „ ... 125-126 „ 



Semicarbazone, „ (170-172 „ ... 170-172 „ 



two forms \ 174-176 „ ... 174-176 „ 



The dextro-rotatory oils not being used for preparation 

 of the pure ketone, but being particularly rich in thujone, 

 they were used directly for preparation of the derivatives r 

 viz: — 



Narrabeen sample, 16/6/21. 

 Tribromide recrystallised from ethyl acetate melting point 



125-126° O. 

 Semicarbazone, soluble in alcohol, melting point 184 - 185°0. 

 Ditto, sparingly ditto 176 - 177°C. 



It will be observed that the melting point of the tribro- 

 mide is much higher than that usually recorded for this 

 ketone, viz., 121-122° O. (Wallach). 



We are greatly indebted to Mr. R. T. Baker, f.l.s., etc., 

 for much assistance in this work, particularly in the 

 botanical portion, and also for his excellent drawing of the 

 floral parts. Our acknowledgements are also due to Mr. 

 F. Morrison for assistance in the chemical part of the 

 investigation, and to Mr. O. F. Laseron for superintending 

 the collection of the botanical material. 



