— 8o — 



this hydrocarbon without any far-reaching change. The author suggests 

 the following two possible formulae: — 



I. II. 



H C HC— —CO H C HC CO 



I 

 CH — CH-CH, 



HC ^ C==CH HC- C===CH 



I I 



CH 3 CH 3 



Both formulae admit of the possibility of the formation of p-cymene, 

 owing to the bridge - rupture by absorption of hydrogen at the spot 

 indicated by the dotted line. Formula I represents a keto pinene, 

 yielding on oxidation a dimethyltetramethylene dicarboxylic acid which 

 should be identical or stereo-isomeric with norpinic acid formed by 

 oxidation of pinene. But this appears to be as little the case, as that 

 umbellulonic acid is stereo-isomeric with pinonic acid. 



For this reason formula II corresponds much better with the 

 construction of umbellulone, and according to this umbellularic acid 

 would then represent i-methylpentamethylene- 3,5 -dicarboxylic acid. 

 The reduction of umbellulone with sodium and absolute alcohol yielded 

 a mixture of two compounds , which were identified as /? - dihydro 

 umbellulone C 10 H 16 O, b. p. 204 to 209 , with a pulegone-like odour 

 and a semicarbazone of the m p. 155 to 15 6°, and as tetrahydro um- 

 bellulone, C 10 H 18 O, b. p. 197 to 198 , with a camphor-like odour, 

 and a semicarbazone of the m. p. 148 . 



Verbena Oil. From the last Report of Roure-Bertrand Fils 1 ) 

 we abstract the following communication regarding Verbena triphylla L. 

 and the oil obtained from it : The oil in question had been distilled 

 during the flowering period of the plant; the roots (including the 

 quantity of oil obtained by extraction of the distillation water) yielded 

 o,oi4°/ , the stalks 0,007% of oil. 



The oil obtained from the leaves and inflorescences had the 

 following composition: — on from 0il from the 



the leaves - inflorescences 



yield in per cent, of the fresh plant °A^5 °i 1 3 2 



« D . . — 14 16' — 8° 24' 



ester 3,5% 3,2% 



combined alcohol 2,8 „ 2,5 „ 



free alcohol. ...,.,.. 16,5 „ 13,8 „ 



citral ........... 35,4 „ 29,6 „ 



*) Berichte, Roure-Bertrand Fils, April 1906, 38; comp also Reports October 

 1900, 64; April 1903, 76; Gildemeister and Hoffmann, The Volatile Oils, 

 P- 593- 



