Chemistry of Essential Oils

N. O. LILIACE^E 93

OIL OP HYACINTH.

The perfume of the flowers of Hyacinthus orientalis is usually em-
ployed in the form of an extract or pomade, but an \ essential oil is ob-
tainable from them.
By extracting hyacinth flowers with benzene and distilling off the
solvent under reduced pressure, precipitating the fatty matter with dilute
alcohol, and again concentrating, Spalteholtz and Enklarr,
1
obtained
0§016 per cent, of crude oil which, until largely diluted, had a somewhat
unpleasant odour. On washing with dilute alkali sulphuretted hydrogen
was detected. After removing the fatty matter by cooling the petroleum
ether solution to - 20°, filtering and removing the solvent, the oil was
fractionated under reduced pressure. The first fraction contained a
very volatile substance, with a disagreeable odour. In the second frac-
tion an unknown oxygenated body was isolated. The third fraction
contained benzyl benzoate, free benzyl alcohol, and a cinnamic ester.
The benzoic acid liberated from an alkaline solution had an odour of
vanillin. A fluorescent body free from nitrogen was also isolated, which
became red with acids and yellow with alkalies. No esters of anthranilic
or methyl-anthranilic acids were detected. The natural wax present
crystallised from alcohol in colourless flakes, which persistently retained
the odour of the flower.

OIL OF ACAEOID EESIN.

The Australian " grass tree gums " Xanthorrh&a hastilis and Xan-

thorrhwa australis yield essential oils of highly aromatic odour. These

oils smell of storax, tolu, or Peru balsam, and have the following char-

acters :—

Xanthorrhcea hastilis Xanthorrhcea australis

(yellow gum). (red gum).

Specific gravity.. 0-937 0-963

Optical rotation. - 3° 14' ± 0°

Acid value ... 4-9 47-6

Ester „... 69-4 37-5

Both oils contain cinnamic acid and the red gum oil contains styrol.

Eennie, Cooke, and Finlayson

2

have investigated the essential oils of

several species of Xanthorrhoea resin. They state that little evidence as

to the species has been forthcoming in previous investigations. The red

resin was obtained from either West or South Australia, and its botanical

source is uncertain. A specimen of the leaves was submitted to Professor

Osborne of Adelaide University, who stated that it would require investi-

gation on the spot to determine whether the leaves belonged to Xanthorr-

h<w tateana (the tree which yields the yellow resin from West and

South Australian trees), or to a variety of that species, or to a different

species altogether. The essential oil distilled from this red resin

amounted to about 0-36 per cent, of the weight of the resin, and was

semi-solid at ordinary temperatures. It was found to consist almost

entirely of paeonol, the peculiar acetophenone derivative found in the

essential oil of Paeonia montan..

The essential oil obtained from the yellow resin, derived from Xan-

thorrhoea tateana, was found to contain paeonol, and a hydroxypaeonol,

1

Chem. Weekblad, 1 (1910), 1.

2

Jour. Chem. Soc.t 1920, 338.