Chemistry of Essential Oils

MYETACE^E 381

Specific gravity 0-9211 at 21°
Optical rotation + 7-5°
Refractive index.1-4760 at 21°
The oil is rich in eucalyptol, and also contains d-a-pinene, a sesqui-
terpene, and a crystalline body, which may be an alcohol, melting at
72*5°. In this the name uncineol and the formula C 10 H 18 O is suggested
OIL OF MELALEUCA NODOSA.
This oil from the Melaleuca has the following characters :—
Specific gravity. 0-8984
Optical rotation
Refractive index
Yield.

+ 11-6°

1-4689 at 18°

0-664 per cent.

The oil contains much d-pinene, eucalyptol, and a sesquiterpene.

OIL OF MELALEUCA TBICHOSTACHYA.
This oil has the following characters:—
Specific gravity 0-914 to 0*915
Optical rotation + 2-3° „ + 3-1°
Refractive index 1-4636 „ 1-4655
Yield 1-25 to 2'58 per cent.
The oil contains a very large amount of eucalyptol, terpenes, traces
of a phenol, and terpinyl acetate.

OIL OF MELALEUCA BBACTEATA.
The oil from the Melaleu^a differs from those from all other members
of the genus. The yield of oil is about 1 per cent., having the follow-
ing characters:—
Specific gravity.1-0320 to 1-0360
Optical rotation - 1-4° „ - 3-1°
Refractive index 1-5325 „ 1-5350
The principal constituent of the oil is methyl-eugenol, with some
eugenol, free cinnamic acid, cinnamic aldehyde, cinnamic alcohpl (?)„
phellandrene, and cinnamyl-(?)-cinnamate.

OIL OF MELALEUCA GENISTIFOLIA.

This oil has the following characters :—

Specific gravity 0-8807

Optical rotation + 32*7°

Refractive index 1-4702 at 22°

Yield. '0-526 per cent.

About 2 per cent, of eucalyptol is present, with 80 to 90 per cent, of

pinene, a small amount of a sesquiterpene, and 5 to 6 per cent, of ter-

pinyl acetate.

OIL OF MELALEUCA GIBBOSA.

This oil has the following characters :—

Specific gravity 0-9138

Optical rotation + 4-5°

Refractive index 1-4703 at 20°

Eucalyptol 61-5 per cent.

Yield 0-16

The oil contains eucalyptol, pinene, and a sesquiterpene.