— 52 — 



It follows that the hydrocarbon -fractions consist for the greater 

 part of p-cymene; in addition to which there are present (but only in 

 small quantities) d- and i-a-pinene, /9-pinene, /? - phellandrene and 

 dipentene. 



II. The Aldehydes. 



The bisulphite-combination, after being purified by washing with 

 alcohol and ether, was decomposed by boiling it with soda solution 

 and then distilled by steam. Its constants were as follows: b. p. 97 

 to 99 (7 mm.) d^o 0,9731, «r> -|~o°3'. When oxidised with chromic 

 acid the aldehyde was converted into cuminic acid, m. p. 113 to 

 1 1 4 . The m. p. of the semicarbazone was 210 to 211 , of the 

 oxime, 55to57 01 ). Cuminic aldehyde (cuminol) which has long been 

 known as forming the principal constituent of oil of cumin, is here 

 present in a state of great purity. It caused some surprise, however, 

 to find the first fraction of the aldehyde showing a slight rotation to 

 the right («p -[-1 13'), but oxidation always gave only cuminic acid. 

 In the course of the fractionated crystallisation of the semicarbazone 

 we succeeded in obtaining, in addition to cuminic aldehyde, semi- 

 carbazone, crystallising in pretty f lakelets, (m. p. 210 to 211 ), another 

 body, m. p. 200 to 20 1°, crystallising in thin prisms. This latter 

 semicarbazone was not found in the other fractions. Further examin- 

 ation failed to confirm the surmise that the two semicarbazones of 

 cuminic aldehyde contained as- and /^^-modifications. When oxidised 

 with chromic acid, the aldehyde forming the basis of the semicar- 

 bazone of the m. p. 200 to 20 1° was also converted into cuminic 

 acid. The oxime of the aldehyde had a m. p. 72 to 76 (impure). 

 It is therefore probable that, in addition to the cuminic aldehyde, 

 there is present, in small proportions, a hydrogenated cuminic 

 aldehyde. We intend in a future contribution to give details of the 

 further examination of this body. 



III. Cuminic alcohol. 



The constituents of the oil which possessed higher boiling points 

 and did not react with bisulphite also had the typical cuminol odour. 

 These were repeatedly shaken with semicarbazide solution. 12 kilos 

 cumin oil yielded altogether about 20 g. Ester no after acetyl. 21 i. 

 It was found impossible to prepare any characteristic derivatives. When 

 oxidised with permanganate, cuminic acid, m. p. 1 12 to 1 13 , was formed. 

 As the cuminic aldehyde itself had been carefully removed from the 

 oil, the only possible conclusion points to cuminic alcohol. Besides 



1 ) Wallach (Liebig's Annalen 340 [1905], 6) gives the m. p. as 58 to 59 , 

 whereas Westenberger (Berl. Berichte 16 [1893], 2994) has found it to be 5 2°. 



