— 44 — 



In addition to the bodies which had long been recognised as con- 

 stituents of citronella oil, e. g. citronellal 1 ), camphene 2 ), dipentene 3 ), 

 methylheptenone 4 ), borneol 5 ), geraniol ) and methyleugenol 7 ), and of 

 valeric acid 8 ) (in the ester-form), Schimmel § Co., in the year 1899 9 ), 

 detected in the oil the presence of Z-limonene, linalool (?) and a light and 

 a heavy dextrorotatory sesquiterpene. We are now able to give the results 

 of an examination of an authentic original oil, which examination has 

 yielded many interesting data on the constitution of this important article 

 of commerce. 



The material worked up by us consisted of portions of numerous 

 fractions which had been obtained by fractional distillation from a large 

 parcel of oil. 



Methylheptenone was found to be present in the first fractions, which 

 boiled over between 120 and 161°. It was separated in the form of the 

 bisulphite compound, and was furthermore identified from the semicar- 

 bazone, m. p. 134 to 135°. The surmise that esters might also occur in 

 this fraction, which had been entertained at the outset, proved upon 

 saponification to be unfounded. A fraction with the following constants: 

 b. p. 156 to 157,5°, di 5 o 0,8633, « D — 15°31', was also tested unsuccessfully 

 for a-pinene. A series of reactions, partly intended to detect the presence 

 of other terpenes, again confirmed the occurrence in the oil of Z-camphene. 

 This examination proved to be particularly interesting because in carrying 

 it out we succeeded for the first time in obtaining from citronella oil 

 camphene in the solid form 10 ) by fractionation. The portions which boiled 

 over between 160 and 163° consisted almost wholly of camphene. In 

 common with the terpene-fractions boiling between 164 and 168° (di 6 o 0,8670 

 to 0,8635; « D — 58° 13' to —61° 14'), — in which latter we had at first 

 expected to find sabinene or /?-pinene, — the fractions in question, when 

 oxidised with permanganate in alkaline solution by Wallach's method, 

 yielded camphene camphoric acid, m. p. 142°. The oil which had undergone 

 no change during oxidation turned solid in the cooler during the process 

 of steam-distillation, and after being purified from alcohol exhibited all 

 the characteristics of ordinary camphene. It melted between 49 and 50°; 

 [«] D — 173°22' (in 10,2°/o solution in chloroform). Fractions which boiled 

 between 160 and 168°, when treated with glacial acetic acid and sulphuric 



*) Berl. Berichte 24 (1891), 210. 



2 ) Journ. f. prakt. Chem. II. 49 (1894), 16. 



3 ) Report October 1893, 15. 

 •*) Report April 1895, 26. 



5 ) Report April 1894, 17. 

 (i ) Report October 1893, 18. 



7 ) Report October 1898, 18. 



8 ) Proceed. Americ. pharm. Ass. 35 (1887), 571. 



9 ) Report October 1899, 16. 

 10 ) Report April 1903, 84. 



