MYBTACE^E 377
OILS OF LEPTOSPERMUM.The lemon-scented Leptospermum Liversedgei is a New South Wales
•shrub, from 6 to 12 ft. in height, which yields about 0
*
23 per cent, of
essential oil, which has been examined by Baker and Smith.^1 The oil
has the following characters:•—
Specific gravity 0'8895
Optical rotation +9;2°
Refractive index 1-4903 at 10°
The principal constituents in the oil are : (1) the aldehyde citral;
(2) an alcohol, which is probably geraniol; (3) an acetic acid ester, which
is probably geranyl acetate; (4) the terpene pinene which was dextro-
rotatory ; and (5) a sesquiterpene, which is probably the constituent
which gives the laevo-rotation to the higher boiling portion. Limonene
could not be detected by any method, and was, therefore, absent; nor
was phellandrene present. The whole of the aldehyde appears to be
citral, as proof of the presence of any other aldehyde could not be ob-
tained, and two determinations by Flatau and Labbe's method failed to
give any indication for citronellal. The secondary odour of the oil, from
which the aldehydes had been removed, strongly resembled that of
geraniol. The oils of the Leptospermums, with this exception, do not
appear to have been investigated chemically, so that the occurrence of
citral in the oil of Leptospermum Liversedgei is of some scientific interest.
The approximate composition of the oil is as follows :—
Citral 35'0 per cent.
Geranyl acetate. 5-35 ,,
Oeraniol 9-74 „
d-pinene.25-0 „
Sesquiterpene and undetermined .... 24- 91 ,,
100-00 per cent.
According to Challinor, Cheel, and Penfold, the leaves of Leptosper-
mum flavescens, var. citratum, yield about 1/8 per cent, of oil having the
following characters:—
Specific gravity 0*884
Optical rotation "....+ 3-6°
Refractive index at 20° 1-4730
It contains about 90 per cent, of aldehydes, which consist of citral
and citronellal in approximately equal amount. A small quantity of an
alcohol (possibly geraniol or citronellol) was found, and a trace of a
phenol. Probably aromadendrene is present.OIL OF DAKWINIA FASCICULARIS.
This oil has been investigated by Baker and Smith.^2
Darwinia fascicularis is a virgate shrub, varying in size in different
localities, about 5 ft. being the maximum height in the coast form. The
mountain variety rarely exceeds 2 ft. The leaves are slender, numerous,
and crowded, and vary in length from four to eight lines. The flowers
although small are attractive, being sometimes all white, or pink and
white.
1
3 Jour, and Proc. Roy. Soc., N.S.W., xxxix. (1905), 124.
., xxxiii. (1899), 163.