Chemistry of Essential Oils

COMPOSITE 293

The oil oxidises on keeping, with the result that the specific gravity
may rise to TOOO, or even over this figure.
, \ ( Tarragon oil contains methyl-chavicol (the " estragol " of Grimaux),
ocimene(?), phellandrene, and some unidentified constituents which
influence its odour and flavour.
\ .•" Artemisia lavandulaefolia, a Javan plant, yields an essential oil con-
taining a crystalline compound of the formula C 12 H 1 4O 2 , melting at 32°
to 33°. It is probably the methyl ester of an unrecognised acid.
Artemisia glutinosa. Bennett* has examined the oil distilled from
this species in Murcia, Spain. It has the following characters :—

Specific gravity 0*937

Optical rotation + 24C

Eefractive index 1-4780

Total alcohols as borneol...... 17 '5 per cent.

Esters as bornyl acetate 6-3 per cent.

Phenols 8 per cent.

Aldehydes and ketones 18 per cent.

Terpenes, probably terpinene or dipentene principally, are present.

Methyl-chavicol is probably present in the oil.

OLL OF EUTHAMIA CAROLINIANA.

This plant, a member of the Compositae, is indigenous to Florida and

Texas, and occurs in greatest abundance near the coast. It is rarely

found on new land or in woods, but frequently in moist sandy fields or

lake bottoms. It flowers from September to November, producing an

abundance of small lemon-yellow blossoms. A quantity of the fresh

herb has been distilled at the Florida station of the Office of Drug and

Poisonous Plant Investigations of the Bureau of Plant Industry, the

material being gathered in old fields adjacent to the City of Orlando,

in Orange County, Florida.

2

The yield of oil from the fresh herb was

€'693 per cent. The oil was pale yellow in colour and possessed a

pleasant aromatic odour and an acrid, slightly bitter, taste, with a

strong terebinthenous after-taste. The oil has the following char-

acters :—

Specific gravity 0'857

Optical rotation.10° 48'

Refractive index 1-4805

No free acids were present even after storing for fifteen months, and

the saponification value was only 6'35. The saponification value after

acetylation was 25'3, equivalent to 7'01 per cent, of alcohols. No

phenols were present, but a trace of aldehyde was indicated by SchifF s

reagent. The oil consisted mainly of dipentene, with a trace of pinene

and possibly limonene. On fractionation about 10 per cent, of highly

laevo-rotatory fractions was obtained, one with a specific gravity of

0

*

9056 and optical rotation - 34° 18', and another of specific gravity

0 *9286 and optical rotation — 63° 18'. These fractions were not further

investigated. The oil was soluble in 6 volumes of 90 per cent, alcohol

«,nd also in 9 volumes of 70 per cent, with slight cloudiness, but did not

become clear on adding an excess of 50 volumes.

lP. andE.O.R. (1920), 286. (^2) Jour. Amer. Cham. Soc. (1916), 1398.