388 THE CHEMISTEY OF ESSENTIAL OILS
detected with certainty in this way. The oil should, when freshly
prepared, also be easily soluble in 90 per cent, alcohol, and when kept
for some time should be soluble with a slight turbidity. This oil is
largely employed in perfumery, especially in the preparation of the
favourite toilet article, bay rum.OIL OF PIMENTO.Pimento Oil or Allspice Oil is distilled from the fruit of Pimenta
officinalis Linn. (Eugenia pimenta De Candolle). The plant, a hand-
some evergreen, is indigenous to the West Indies, being found especially
on calcareous soil near the coast on the islands of Cuba, Hayti, Trinidad,
Domingo, Antigua, the Leeward and Windward Islands, and in abund-
ance in Jamaica. It also occurs in Mexico, Costa Eica, and Venezuela.
The bsrries are gathered in an unripe condition, as when ripe they are
filled with a sweet pulp lacking the characteristic aroma of the green
berry. These unripe berries, dried in the sun, form the pimento of
commerce, and Jamaica alone exports, chiefly from the port of Kings-
ton, about £50.000 worth per annum. The fruit, which is about the
size of a small pea or large peppercorn, has an aromatic odour some-
what recalling cinnamon, nutmeg, and pepper, with a predominating
odour of cloves. This explains the origin of the name allspice. It
yields from 3 to 4^ per cent, of oil on distillation, of a dark reddish
colour and of the same aromatic odour as the fruit.
The oil contains the phenol-eugenol with small quantities of cineol,
laevo-phellandrene, caryophyllene, eugenol-methyl ether, and palmitic
acid. The eugenol is, of course, responsible for the clove-like odour of
the oil, and the other bodies, together with one or more as yet unknown
constituents, modify the characteristic odour of the oil. A certain
amount of resin, due no doubt to the unstable nature of some of the
constituents, is usually present. The actual amount of eugenol in the
oil is approximately estimated by absorption with 5 per cent, caustic
soda solution, as in the case of oil of cloves.
The oil has the following characters :—-
Specific gravity 1-024 to 1-056
Optical rotation - 0° 40' to - 5°
Refractive index 1-5250 to 1-5350
Phenols 65 to 80 per cent.
It is soluble in 2 volumes of 70 per cent, alcohol, with at most slight
turbidity.
Pimento leaves yield an oil of similar composition, having the fol-
lowing characters:—
Specific gravity 1-026 to 1-030
Optical rotation - 4° to - 5° 30'
Phenols 65 to 70 per cent.
OIL OF AMOMIS JAMAICENSIS.The wild pimento of Jam lica, as it is called, is Amomis jamaicensis,
a tree growing to a height of 40 feet, found on ths limestone in the
woods of Upper Clarendon and in the Dry Harbour mountains. The tree
is a new species only named in 1919 by the Government botanists, and
experiments are being undertaken with a view to developing the dis-
tillation of its essential oil. In an experimental distillation by the