Chemistry of Essential Oils

CONIFEE^E 35

used, but with a series of bulbs, from 25 to 35 per cent, is obtained be-
tween 155° and 160°, and from 10 to 20 per cent, between 270° and 280°.
With our present knowledge of this oil, no further analytical methods
are yet available. A good juniper oil should contain sufficient cadinene
for the residue after distilling off 75 per cent, to have a refractive index
of 1-4950.
Umney^1 has reported on the effect of age on an English distilled
juniper oil, which is no doubt identical with what takes place with other
oils. The oil when distilled in 1898 had a specific gravity 0 871. In
1914, this figure had risen to 0977, and the refractive index was 14960.
Jumper wood oil, as met with in commerce, is not a natural product
at all. It is usually a mixture of turpentine with sufficient juniper berry
oil to give it an odour of juniper oil.
The berries of Juniperus phanicea, which are found in Cyprus, yield
an oil having the following characters :—
Specific gravity 0-867 to 0-870
Optical rotation + 3° „ + 5°
Refractive index ........ about 1'4710
The leaves of Juniperus phwnicea yield an oil iwhich has been in-
correctly offered in the market as oil of savin. —
The berries of Juniperus oxycedrus yield about 15 per cent, of essen-
tial oil having the following characters :—
Specific gravity
Optical rotation
Refractive index

0-850

- 4°

1-4710

to^0856

-10°

1-4735

The wood of this plant yields up to 3 per cent, of oil of specific gravity

0925, and optical rotation - 30°.

OIL OF CYPEESS LEAF.

Oil of cypress is distilled from the leaves of Cupressus sempervirens

(fastigatd), the yield being from 0*2 to 1*2 per cent. Cupressus lusi-

tanica also yields a similar essential oil.

This oil is popularly supposed to be a remedy for whooping-cough,

but its efficacy in this respect can scarcely be said to be soundly estab-

lished. The oils have the following characters :—

Specific gravity.

Optical rotation.

Refractive index.

Acid value

Saponification value

,» >»

Specific gravity

Optical rotation

Refractive index

Acid value

Ester ,.

,, ,, (after as

FrenchOils.

Cupressus

sempervir ens.

Cupressus

lusitanica.

. 0-868 to 0'S84 0-872

• 12°+
  . 1-4710 ,
  0-7

(^3 1)
(after acetylatioii). 9
German
etylation) 3
Oils.

• • •

, + 31° + 9° 10

, 1-4760 —

, 2 1

, 16 9-8

, 32 26-6

Cupressus

sempervirens.

0-880 „ 0-900

+ 4° „ + 18°

1-4740 „ 1-4800

1-5 ,, 3

13 „ 22

36 „ 51

1

P. and E.O.R., 1914, 5.