154 THE CHEMISTRY OF ESSENTIAL OILS
Specific gravity... 0-885 to 0-898
Optical rotation ... + 6° „ +13°
Aldehydes.... 79 to 86 per cent, (bisulphite method).
The principal constituent is citral, with some geraniol, geranyU
esters, and a terpene.
The leaves yield about 5 per cent, of oil having the following
characters:—
Specific gravity 0-899 to 0*917
Optical rotation - 12° „ - 16°
Refractive index 1-4644
It contains from 20 to 35 per cent, of cineol, citral, and an alcohol
which is probably geraniol.
The bark yields from 0*1 to 0*8 per cent, of oil of the following
characters:—
Specific gravity 0'866 to 0-906
Optical rotation + 10° „ + 21°
Ester value after acetylation 230° „ 252°
The oil contains, according to Charabot and Laloue, 8 per cent, of
citrol, 10 per cent, of citronellal, 56*5 per cent, of alcohols (geraniol ?)
and 2*4 per cent, of esters.
OIL OF MBSPILODAPHNE PBETIOSA.This tree is one of the Brazilian Lauracea (also known as Ocotea
pretiosa), and all parts of the plant appear to yield an essential oil.
Laloue l has examined the oil obtained from the twigs and from the
wood. From 1600 grm. of the dry twigs he obtained 79 grms. of oil
(05 per cent.), having a pronounced odour of linalol. From 25 kilos
of the wood he obtained 1732 grms. of oil (0*693 per cent.), which
had an odour recalling that of rosewood and cinnamic alcohol. The
oil (4) was easily separated into a light (2) and a heavy (3) oil. The
benzoic esters of linalol and geraniol were found present. The follow-
ing are the general characters of the oils, No. 1 being the twig oil:—
Specific gravity
Rotation.
Refractive index
Acid value
Saponification value
Esters as linalyl acetate
Acetyl ester value.
Alcohols as linalol.1.
0-891
+ 7° 20'
1-469
1-4
13-3
165
51-8
2.
0-954
+ 8° 48'
1-501
0-8
100-7
35-3
205
66-6
3.
1-055
+ 3° 8'
1-545
3-5
203-7
248
—
4.
0-981
+ 7° 12'
1-519
2-1
128-1
220
—
The oil from the bark has been examined by Schimmel & Co.
2
The bark yielded 0 * 83 per cent, of a brown oil of cinnamon-like odour.
Its specific gravity was 1-1200 (15°) and its refractive index 1*52712 (20°);
owing to the dark colour it was not possible to determine the rotation.
It was soluble in 6*5 volumes of 80 per cent, alcohol. It is probable
that its constituents do not include esters, but lactone-like compounds,
for when 1-5 grm. of the oil was saponified, 5 c.c. seminormal potash(^1) Bull. Soc. Chem., H, 602. (^2) Report, April, 1913, 76.