— 76 — 



Semmler and Zaar 1 ) have discovered that the alcohol C i0 Hi 6 O, which 

 was recently 2 ) obtained by them from perillic aldehyde 3 ) is identical with 

 the alcohol Ci Hi 6 O 4 ) which was discovered by us as a constituent of 

 gingergrass oil a good many years ago, and which at the time we identi- 

 fied by its constants and oxidation products as a dihydrocuminic alcohol. 

 The authors 5 ) in question had already shown that the perillic alcohol is 

 derived from lunonene, and that therefore one of the two double bonds 

 of its skeleton is to be looked for in the side-chain. Hence the ginger- 

 grass alcohol is not a true dihydrocuminic alcohol. 



At the beginning of their paper Semmler and Zaar again enumerate 

 the constants of dihydrocuminic alcohol, dihydrocuminic aldehyde and 

 dihydrocuminic acid and their derivatives, which had already been as- 

 certained by us. They then give, as the result of their own observations 6 ), 

 the constants of the alcohol alone, as follows: b. p. 107 to 110 (12,5 mm.), 

 d 20 o 0,946, n D 1,4968. The chloride boiled at 97 to 102° (14 mm.) and was 

 reduced to limonene ([«]fl — 15° 30') by treating it with sodium in absolute 

 alcohol. The tetrabromide melted at 125°; and the body therefore principally 

 represented the inactive form of the hydrocarbon (dipentene). Hence 

 the atomic structure of the gingergrass alcohol must be the same as 

 that of the perillic alcohol, namely: 



C-OVOH C-CH 3 



HC^\CH 2 HC^\CH 2 



H 2 Cl /CH 2 H 2 CL JCH 2 



CH CH 



H 2 C:C-CH3 H 2 C:C*CH3 



Alcohol CioHieO Limonene 



from gingergrass oil. 



The property of dihydrocuminic alcohol of forming a naphthyl ure- 

 thane, m. p. 146 to 147°, with naphthyh'socyanate has not been utilised 

 by the authors for the purpose of making a further comparison between 

 it and the perillic alcohol. 



On oil of Andropogon Schcenanthus var. nervatus, see p. 19. 



Oil of Iris versicolor, L. F. B. Power and A. H. Salway 7 ) have 

 distilled the oil from the dry roots of this plant, (N. O. Iridacea?), a native of 



!) Berl. Berichte 44 (1911), 460. 



2 ) Ibidem 44 (1911), 54. 



3 ) See p. 93. 



*) Report April 1904, 57; October 1904, 44; April 1905, 42. Walbaum and Huthig, Journ. 

 f. prakt. Chem. II. 71 (1905), 464. 



5 ) Log. cit. 



b ) We supplied the authors with the raw material for their investigation. The name 

 "gingerol" which had been previously given to our alcohol by Semmler is now abandoned 

 because it was afterwards found to have been already appropriated for another body. 



<) Americ. Journ. Pharm. 83 (1911), 2. 



