Chemistry of Essential Oils

460 THE CHEMISTEY OF ESSENTIAL OILS

about the Gulf of Santa Fe. The name angostura appears to have been
given to it on account of its having been found first in the district bear-
ing that name, situated on the Orinoco. The oil has the following
^characters:—

Specific gravity ......

Optical rotation ......

Refractive index

Acid value .......

Ester ,,

,, ,, (after acetylation)

. 0-930 to 0-960

• 7° „ - 50
  1-5074
  1-8
  5-5
  35-7
  It has been investigated by Beckurts and his pupils.^1 In their
  earlier investigations they obtained 1*5 per cent, of oil from the bark, of
  specific gravity -956. More recently they obtained the same yield of oil
  of specific gravity '941 at 20°, of optical rotation - 50°. The oil decom-
  poses partially, when distilled under ordinary pressure, with the forma-
  tion of water. A small portion was obtained boiling at 160°, and having
  an odour resembling pinene. A small quantity of a terpene is thus
  probably present. The main portion of the oil, however, distils between
  260° and 280°. and consists of a sesquiterpene and a sesquiterpene
  alcohol. The sesquiterpene, which is laevo-rotary, was originally de-
  scribed under the name galipene, but has now been shown to be identical
  with cadinene. The alcohol C 16 H 16 O is termed galipol; it is a liquid of
  specific gravity '927 at 20°, and is optically inactive. By the action of
  dehydrating agents this body gives up water and yields cadinene. In ad-
  dition to these bodies there is also present a small quantity of an inactive
  sesquiterpene, and traces of a crystalline stearoptene. The oil is used to
  a small extent, chiefly for the preparation of liqueurs, etc.

JABOBANDI LEAF OIL.

The leaves of Pilocarpus Jaborandi yield about 5 per cent, of an

essential oil having the following characters :—

Specific gravity 0'8G5 to 0-895

Optical rotation....... - f 1° ,, + 4°

It is soluble in 2 volumes of 80 per cent, alcohol. Its composition

is not well known, but the terpene dipentene has been identified, and

also a crystalline hydrocarbon, belonging to one of the unsaturated series.

The latter body sometimes occurs to so great an extent that the oil solidi-

fies on cooling. It also contains methyl-nonyl ketone.

OIL OF EVODIA EUT^CARPA.

The essential oil distilled from the fruit has been examined by

Asahina and Kashiwuki.^2 The authors have isolated from it a ter-

pene which they believe to be different from any of the known terpenes,

and which they have named evodene. It is a colourless liquid boil-

ing at 67° (20 mm.), with a sharp odour, and has the characters of an

aliphatic terpene of the formula C 10 H 16. It has a specific gravity of

0-799 and refractive index 1*4843. On treatment with plantinum

black it is converted into dimethyl-octane. It resembles the olefinic

terpenes myrcene and ocimene, but differs from them in forming a

liquid tetrabromide after reduction to dihydro-evodene. A crystalline

substance melting at 278° has also been isolated from the fruit, which the

1

• Arch, der Pharm.,^237 (1897), 518 and 634 ; 236 (1898), 392 ; 229 (1891), 612.
  Jour. Pharm. Soc. Japan, November, 1915.