Chemistry of Essential Oils

MYBTACE.E 389

Government Department, 100 Ibs. of the leaves yielded 202 c.c. of a pale

yellow mobile oil. This has been examined in the laboratory of the

Imperial Institute and found to have the following characters:—

Specific gravity 0-8895

Optical rotation — 6°

Ester value 4-2

„ „ (after acetylation) 129-4

It is soluble in 2-5 volumes of 70 per cent, alcohol, becoming cloudy

with 6 volumes.

The principal constituent appears to be linalol, so that the oil has no

resemblance to ordinary pimento oil.

CHEKEN-LEAF OIL.

Cheken-leaf Oil is the product of distillation of the leaves of Myrtus

cheken, a plant indigenous to Chili. The yield is about 1 per cent, of a

pale yellowish-green oil, much resembling ordinary myrtle oil. Its odour

recalls that of myrtle, eucalyptus, and sage oils. According to Weiss,^1

its specific gravity is about

• 880, and its optical rotation about + 20°; it
  consists of pinene (75 per cent.), cineol (15 per cent.), and substances not
  further examined.

OIL OP BACKHOUSIA.

Backhousia citriodora is a small tree indigenous to Queensland. The
leaves yield about 0*7 per cent, of essential oil which resembles lemon-
grass oil closely in odour. The oil has the following characters:—

Specific gravity 0-895 to 0'900

Optical rotation 0° to - 0° 30'

Refractive index 1-4860 to 1-4890

Citral value 93 to 96 per cent.

The oil probably contains small quantities of a sesquiterpene.

OIL OF MESPILODAPHNE.

Mespilodaphne pretiosa is a South American tree, known as " Pris-
prioca ". It is a native of Eio Janeiro and Minas Geraes. The branches
yield 0'5 per cent, of an essential oil having an odour of cinnamon. It
has the following characters :—

Specific gravity

Optical rotation

Kefractive index

Esters ....

Total alcohols (as linalol)

0-8912

+ 7° 25'

1-4690

4-65 per cent.

51-8

The wood oil separates on distillation into a light and a heavy oil.
The light oil has a specific gravity 0953, optical rotation + 8° 48', and
refractive index 1501. It contains 35 per cent, of esters calculated as
linalyl acetate, and 666 per cent, of total alcohols calculated as linalol.
The heavy oil has a specific gravity 1055, optical rotation + 3° 8', and
refractive index 1*5450. It consists chiefly of linalyl or geranyl benzoate.

1

Arch, der Pharm., 226 (1888), 666.