Chemistry of Essential Oils

372 THE CHEMISTEY OF ESSENTIAL OILS

OIL OP EUCALYPTUS SQUAMOSA.

This oil has the following characters :—

Specific gravity 0-9182

Optical rotation 0°

Refractive index 1*4692 at 16°

Yield 0-65 per cent.

It contains about 60 per cent, of eucalyptol, pinene, and aroma-

dendral.

OIL OF EUCALYPTUS STAIGEBIANA.

This tree is the Lemon-scented Iron-bark of Queensland, the es-

sential oil being of particular interest, as it differs entirely from ordinary

eucalyptus oils. The oil has the following characters :—•

Specific gravity 0-8708 to 0-880 (0-901 ?)

Optical rotation - 43-1°

Refractive index. ..... 1'4871 at 16°

Yield 2-5 per cent.

The oil has been carefully investigated by Baker and Smith. In

the course of fractional distillation only a few drops came over beldw

175°, but between that temperature and 193° C. 65 per cent, distilled ;

this fraction had specific gravity at 23/15° C. = 0*851, and refractive

index at the same temperature, 1-4798. Between 193° and 265° C., 23

per cent, distilled, the specific gravity of this = 0*8828 at 23° C., and

refractive index 1*4846 at the same temperature. Between 265° and 300°

C. only 2 per cent, distilled; this had a refractive index 1*5033, and was

quite acid. On again rectifying the first fraction (65 per cent.) nothing

came over below 175° C.; but 40 per cent, of the fraction distilled be-

tween 175° to 177° C.; the rotation of this in 100 mm. tube was

• 662° ([a]D - 7818°), the specific gravity = 08468 at 22/15° C., and
  the refractive index = 14793. Between 177° and 179° C. 23 per cent,
  distilled; the rotation was - 64*8°, the specific gravity = 0

• 8533° at
  22/15° C., and the refractive index = 1482. Between 179° and 184° C.
  17 per cent, distilled; the rotation was - 609°, the specific gravity
  = 08534, and the refractive index = 14828.
  The crystallised tetrabromide was formed in the usual way with the
  portion distilling 175° to 177° C., and these crystals, when purified to
  constant melting-point with acetic ether, melted at 104° to 105° C.
  From the physical properties of the several fractions it may be assumed
  that nearly the whole of the terpene present was laevo-limonene, and
  that the oil contained about 60 per cent, of that terpene.
  An aldehyde determination in the usual way, with 30 per cent,
  sodium bisulphite solution, gave 16 per cent, of aldehydes. The pre-
  paration of the non-aldehydic oil was carried out quantitatively to act
  as a check on the other determinations. Thirty grms. of oil gave 254
  grms. of non-aldehydic constituents equal to 1533 per cent, of alde-
  hydes.
  The rotation of the non-aldehydic oil was — 468°, the specific gravity
  = 08658 at 22/15° C., and the refractive index » 1*4831. It was very
  aromatic.
  The ester determination was carried out on the non-aldehydic oil.
  The saponification number was 28


• 
  

  3, equal to 9

  
  


• 
  

  9 per cent, of ester cal-