Chemistry of Essential Oils

56 THE CHEMISTEY OF ESSENTIAL OILS

The oil contains Z-a-pinene, Z-phellandrene, sylvestrene, cadinene, and
bornyl acetate. Bocker and Hahn have recently isolated from the oil an
aldehyde of the formula C^H^O,^1 an oxygenated body of the formula
C 15 H 24 O, the nature of which has not yet been determined, and a body
of the formula C 8 HUO, having the characteristic odour of the oil. This
body is a cyclic compound, and has been named pumilone, having the
general characters of a ketone. It has the following characters :—
Specific gravity 0-9314
Boiling-point 216° to 217°
Optical rotation......... — 15°
Refractive index ......... 1-4646
The principal adulterant of this oil is ordinary turpentine, which, of
course, reduces the ester value, and yields a large amount of distillate
below 165°.

5. Oil of Abies excelsa.—This oil is distilled from the leaves and twigs
   of Abies excelsa (Abies pectinata, De Candolle; Abies alba Mill.). It has
   the following characters :—
   Specific gravity 0'865 to 0-888
   Optical rotation - 30° „ - 65°
   Refractive index 1-4730 „ 1-4755
   Esters as bornyl acetate 4 to 12 per cent.
   Ib contains Z-a-pinene, Z-limonene, bornyl acetate, lauric aldehyde,
   probably traces of decyl aldehyde, and the hydrocarbon santene, C 9 H 14.^2
   An oil is also distilled from the young cone's of this tree. It contains
   more terpenes than the leaf oil, and has the following characters :—

Specific gravity..0-850 to 0-890
Optical rotation - 60° „ - 85°
Ester value 1 ,, 1 „ 6
It consists chiefly of Z-pinene and Z-limonene, with a small amount
of bornyl acetate.

6. Douglas fir-needle oil.—This oil is distilled from the leaves of
   Pseudotsuga taxifolia, the so-called Douglas pine, a native of North
   America. The needles, twigs, and very young wood are used for the dis-
   tillation, and the yield is from 0*8 to 1 per cent. The oil has been
   examined by Brandel and Sweet and by A. W. Schorger. The oil in-
   vestigated by the first-named was distilled in Washington, whilst that
   examined by Schorger was distilled in California. The two oils had the
   following characters:—

Specific gravity

Optical rotation

Refractive index

Acid value.

Ester ,,

Bornyl acetate

Free borneol

Whether the difference in locality alone is responsible for the dif-

ference in the oils is not clear. Six hundred grams of the oil were

fractionated by Schorger. *

The following compounds were identified in the oil: (1) Furfural.—

This was isolated by shaking the first fraction distilled with water. (2)

a-Pinene.—By repeated fractionation 151 grms. of oil, boiling at 156° to

lJour. prakt. Chem., ii. 83 (1911), 489. (^2) Aschan, Bericht, 40 (1907), 4919.
ndel and Sweet.
0-868

• 62-5°

0

86*6

30-3 per cent.

—

Schorger.

0-873 to 0-876

• 17° „ - 22°
  1-4758 „ 14780
  0-65 „ 1-1
  11 „ 25
  3-9 per cent.
  4-5 to 8-5 per cent.