Chemistry of Essential Oils

348 THE CHEMISTEY OF ESSENTIAL OILS

Wales form of Eucalyptus amygdalina is almost twice that obtained
with the Tasmanian trees, and even Eucalyptus dives appears to yield a
greater quantity of oil than does the Eucalyptus amygdalina of Tasmania.
The oil of the Tasmanian Eucalyptus amygdalina differs from that of
ihe New South Wales form in that it contains much less eucalyptol, has
a very high laevo-rotation, contains more phellandrene, and is much less
soluble in alcohol. The odour of the oil is also much less aromatic."
The oil has the following characters :—
Specific gravity
Optical rotation
Befractive index
Eucalyptol.
Yield.

0-8668 to 0-8848

• 59-1° „ - 75-1°
  1-4761 to 1-4790 at 18°
  12 „ 24 per cent.
  1-62 „ 2-04
  The chief constituents of the oil are phellandrene, eucalyptol, piperi-
  tone, and a sesquiterpene.

OIL OF EUCALYPTUS ANDBEWSI.

This oil is obtained from a tree growing in the north-east of New

South Wales. It has the following characters :—

Specific gravity. 0-8646

Optical rotation - 41-5°

Befractive index 1-4854

Ester number ......... 4*3

Yield 1*27 per cent.

It contains Z-phellandrene, piperitone, and a sesquiterpene.

OIL OF EUCALYPTUS ANGOPHOROIDES.

This tree is found in New South Wales. The oil has the following

characters :—

Specific gravity 0 9049

Optical rotation - 12-7°

Befractive index 1'4881 at 16°

Yield 0-185 per cent.

It contains phellandrene, pinene, eucalyptol and a sesquiterpene.

OIL OF EUCALYPTUS APICULATA.

Eiicalyptus apiculata is a New South Wales tree, the leaves of which

yield O65 per cent, of essential oil containing pinene, piperitone, and a

small amount of eucalyptol, and having the following characters :—

Specific gravity 0'9056 to 0-9112

Optical rotation - 8-6° „ - 9'3°

Refractive index 1-4934 at 16°

Saponification value 8*7 to 10-1

OIL OF EUCALYPTUS AUSTKALIANA.

The tree described up till 1915 under the name Eucalyptus amyg-

dalina, growing on the Australian mainland, was referred to under that

oil. The importance of the oil sold under that name in commerce war-

rants an exhaustive examination of the scientific nomenclature of the

trees bearing the name. This has now been undertaken by Baker