Chemistry of Essential Oils

VEKBENACEJE 271

The so-called Spanish verbena oil is derived from a Labiate plant.
The yield of oil from the leaves varies from 0 07 to 02 per cent.
The oil has the following characters :—
Specific gravity... 0-900 to 0-920
Optical rotation... - 10° „ - 17°
Aldehydes.... 20 to 40 per cent, (rarely to 50 per cent.)
Australian verbena oil, of uncertain origin, but possibly distilled
from the same plant, has a specific gravity about 0

• 890 and an optical
  rotation - 6° to - 16°.
  Verbena oil is rarely soluble in either 70 or 80 per cent, alcohol.
  The principal odorous constituent of the oil is citral. Theulier
  1
  has
  identified geraniol, Z-limonene, a sesquiterpene, and a paraffin hydro-
  carbon melting at 625°. Myrcene has been reported as present, but
  the oil examined was probably lemon-grass and not true verbena oil.
  Kerschbaum^2 has made an exhaustive examination of the genuine oil
  and has isolated therefrom an aldehyde C 10 H 16 O, which he has named
  verbenone, and which had the following characters:—
  Specific gravity..... 0974 at 17°
  Boiling-point at 16 mm.103° to 104°
  Optical rotation.+66°
  Refractive index.1-4995
  Melting-point of semicarbazone 208° to 209°
  The following results were obtained by Messrs. Eoure-Bertrand
  from oils distilled in Grasse at the time of early flowering:—
  From From
  Leaves. Inflorescence.
  Percentage yield from the fresh plant. 0*195 0'132
  "DEsters.
  Combined alcohols
  Free alcohols
  Citral.

• 14° 16' - 8° 24'
  3-5 per cent. 3*2 per cent.
  2-8 „ 2-5
  16-5 „ 13-8
  35-4 „ 29-6

The root yielded 0*014 per cent, and the stems 0'007 per cent, of

essence.

LANTANA OILS.

Lantana Gamara is a tropical plant, common in Java, Farther

India, the Philippines and New Caledonia. Bacon

3

has examined the

oil distilled from the leaves, and found it to have the following char-

acters :—

OrtO

Specific gravity at ^L 0-9132

Optical rotation at 30° + 11-5°

Refractive index at 30° 1-4913

A Java oil has been examined, which had a specific gravity 0*952

and optical rotation — 0° 24'.

Kanga 4 has examined samples distilled from the flowers and leaves

of plants grown in Farther India, and found them to have the following

characters:—

(^1) Bull. Soc. GMm., iii. 27 (1902), 1113. (^2) Bericht, 33 (1900), 886.

• Philip. Jour. 8ci.t 4 (1909), 12. 4 Arch. der. Pharm., 252 (1914), 1.