Chemistry of Essential Oils

162 THE CHEMISTEY OF ESSENTIAL OILS

doubt that the synthesis of c^/cZoisoprene-myrcene represents the first
complete synthesis of a sesquiterpene.
Conversion of myrcene into a-camphorene by heating in a sealed
tube affords an excellent method for detecting the presence of myrcene,
especially when only a small quantity of the terpene is available.
Camphor oil distilled from trees growing in the Federated Malay
States and in Mauritius have been examined by the chemists to the
Imperial Institute.
1
The camphor tree was first grown experimentally by the Depart-
ment of Agriculture in the Federated Malay States in 1904, when seeds
obtained from Japan were sown at Batu Tiga, Selangor. The seedlings
were planted out when about six months old at a distance of 10 ft. by
10 ft. The cpnditions at this place appear to be well suited to the tree,
and the growth of the plants is stated to have been equal to that seen
in Japan.
Distillation was first carried out experimentally in 1909, and has
been continued at intervals ever since. In 1911, by using a wooden
still of the Japanese type, a yield of 0

• 13 to 0*5 per cent, of camphor
  and camphor oil was obtained from fresh green prunings. In subse-
  quent experiments, using a galvanised iron condenser, fresh prunings
  from four-year-old trees gave yields from 0


• 
  

  53 to 0

  
  


• 
  

  77 per cent., whilst
  air-dry material from two-year-old trees gave 0'60 to 0 80 per cent, with
  a metal condenser. The leaves and twigs distilled separately gave the
  following results:—
  Leaves. Twigs
  Two-year-old trees.. 1/4 to 1-6 per cent. O'lO to 0-25 per cent.
  Four-year-old trees.. 1-3 „ 1-7 „ 0-13 „ 0-22 „
  The distillate in all cases consisted principally of camphor, with only a
  small quantity of camphor oil.
  In 1912 specimens of camphor oil and camphor produced in the
  Federated Malay States were examined at the Imperial Institute, and
  the oil was found to contain 193 per cent, of camphor, whilst safrol, the
  characteristic and valuable constituent of the Japanese oil, was absent.
  In 1913 a further sample of camphor oil was received at the Im-
  perial Institute which consisted of a pale yellow oil containing a con-
  siderable deposit of camphor. By cooling the oil to - 12°, a yield of
  14*9 per cent, of crystalline camphor was obtained, and the residual oil
  possessed the following constants compared with corresponding figures
  for the previous sample:—•

  
  

Specific gravity (15°) 0'92

Optical rotation (100 mm. tube).

Acid value

Saponification value ....

,, „ of acetylated oil

1913

Sample.

. 0'920
. + 38° 23'
1-1
36
. 257

Previous

Sample.

0'913

+ 41° 1

On fractionating the residual oil about 4'3 per cent, of cineol was ob-
tained, and a further yield of 15'7 per cent, of camphor, giving a total
yield of 30*5 per cent. No safrol was detected, its absence being prob-
ably due to the fact that the oil was obtained from the prunings of
young trees. The camphor oil from the Federated Malay States differs,

1

Bull. Imp. Ins*., xiv., 4 ; and P. and E.O.R. (1917), 173.