Chemistry of Essential Oils

360 THE CHEMISTEY OF ESSENTIAL OILS

OIL OF EUCALYPTUS LARGIFLORENS.

This tree is a Tasmanian eucalypt. Its oil contains eucalyptol,
pinene, and esters, and has the following characters:—

Specific gravity 0*9155

Optical rotation

Refractive index

Eucalyptol

Yield

+ 5-5°

1*4676

50 per cent.

0-67

OIL OF EUCALYPTUS LONGIFOLIA.

This oil contains eucalyptol, pinene, and a sesquiterpene, and has
the following characters :—
Specific gravity 09226
Optical rotation + 28°
Refractive index 1-4738 at 16°
Yield 0-535 per cent.

OIL OF EUCALYPTUS LOXOPHLEBA.

This tree is the Western Australian York Gum. The oil contains
phellandrene and eucalyptol, and has the following values :—

Specific gravity 0-8828

Optical rotation......... + 5°

OIL OF EUCALYPTUS LUEHMANNIANA.

This oil has the following characters :—

Specific gravity 0*879

Optical rotation - 31-3°

Refractive index 1-4937 at 16°

Yield 0*29 per cent.

It contains phellandrene, eucalyptol, piperitone, and probably cifcral.

OIL OF EUCALYPTUS MACAKTHUBI.
This is one of the most interesting of the eucalyptus oils as it differs
materially from nearly every other one. It has been investigated fully
by Smith.
1
The crude oil of Eiicalyptus macarthuri, obtained by steam distilla-
tion from fresh material of leaves and terminal branchlets, is reddish
in colour owing to the presence of a small amount of free acid in the
original oil. In appearance, odour, etc., it resembles more than any-
thing else the crude oil of Darwinia fascicularis, but the higher boil-
ing portion consists largely of eudesmol, the stearoptene of eucalyptus
oil, which constituent is absent in Darwinia oil. Although containing
this stearoptene no crystals were obtained when the crude oil was
placed in a freezing mixture, eudesmol being so exceedingly soluble
in the oil.
The oil had the following characters:—
Specific gravity 0-9245
Optical rotation.........+ 3-6°

(^1) Jour. Proc. Roy. Soc., N.S.W., xxxiv. 142.