86 A. R. PENFOLD. 
Determination of the Aldehyde.—The fraction of boiling 
point 87—90° C. at 10 mm. resembling citronellal was used 
directly for the preparation of the 2-napthocinchoninic acid 
derivative and the semicarbazone, both of which were 
readily obtained. The former melted at 225° C., and the 
latter, after re-crystallisation from chloroform and petro- 
leum ether, at 82°5° C., thus proving the aldehyde to be 
citronellal. 
The fractions of boiling point 84—87° C., and 87- 90° C. 
at 10 mm. were mixed and combined with sodium bisulphite 
solution. After purification the solid bisulphite compound 
was decomposed by means of sodium carbonate, and steam 
distilled, when avery poor return of citronellal was obtained. 
As thus obtained it possessed the following characters:— 
Boiling point at 10 mm.... .. 88—89° ©. 
Specific gravity 42° O. ... 0 058569 
Specific rotation |[@]p 20° c. 2, 
Refractive index, 19° C. ... w.  1°4468 
Semicarbazone, melting point’... 78—79° C. 
Judging from the melting points of the semicarbazones,. 
the aldehyde appears to consist of a mixture of the two 
isomers. Citral was not detected. 7 
Determination of presence of other constituents.—The 
higher boiling fractions were heated with phthalic anhydride 
but no free alcohols, such as geraniol or citronellol, were 
detected. After removal of the aldebyde, the other dextro- 
rotatory constituent was found to be a sesquiterpene, which 
gave the usual colour reactions for such bodies usually 
occurring in the essential oils of the Myrtaceee. 
Determination of a Paraffin.—From the residue left. 
after distillation a saturated paraffin was isolated of melt- 
ing point 62 —63° C. 
This particular essential oil, therefore, consists of citro- 
nellal (827%), the remainder being d-a-pinene, sesquiterpene, 
paraffin, and probably a little ester. 
