SANTALACEJE 181
quality of wood, being cut out, and the tree is stripped of its bark, and
the logs thus obtained are sent to various depots, where they are cut into
the usual sized billets and dressed and sorted for the auction sale. The
pieces which are straight and have most heartwood fetch the highest
prices, as they contain the highest percentage of essential oil.
The amount of oil obtained from the wood is very variable, generally
from 15 to 6 per cent., but usually from 3 to 5 per cent. Briggs
l
has
described the following method of determining the amount of oil in the
wood and gives the results of twelve samples of wood obtained from My-
sore, representing the various grades there obtainable. Sandal-wood oil
contains a large amount of fixed oil as well as volatile oil, and both are
extracted by ether. The essential oil cannot be separated by distillation
in vacuo, unless glycerine is added to assist in carrying over the last
traces of oil. The latter can be extracted from the glycerine by means
of chloroform. The process adopted was as follows: 100 grams of the
finely powdered drug was extracted in a Soxhlet for twelve hours, or until
completely exhausted. The ether extract was transferred to a 200 c.c.
distillation flask with side neck, and the ether evaporated by the aid of
a current of air. Twenty-five c.c. of glycerine was then added, and the
mixture distilled in vacuo until about 25 c.c. distilled over. Seventy-five
c.c. of water was added to the distillate, and the mixture extracted with
three successive quantities of 25 c.c. of chloroform, and the chloroform
evaporated over a water-bath with the aid of a stream of air. The
residual oil was then dried in a vacuum desiccator over sulphuric acid
and weighed. From 3 5 to 8*3 per cent, of oil was obtained from the
twelve samples of wood. In the course of this investigation it was noted
that the oil obtained by this method had an optical rotation of - 18° or
over, whereas the same wood, distilled with steam, yielded an oil with an
optical rotation of - 14° or less. It was also noted that the oil obtained
by the assay method above described was readily soluble in 5 volumes
of 70 per cent, alcohol, whereas the oil obtained by the ordinary distilla-
tion method required more than 5 volumes. The results of distilling
500 grams of sandal-wood with steam, showing the characters of each
day's running, are of particular interest:—
1 2 3 4 5 6 7 8 9
10
11
12
13
Specific
Gravity.0-969
0-970
0-972
0-974
0-976
0-978
0-978
0-9795
0-981
0-9815
0-982
0-983
0-983
Refractive
Index.1-5017
1-5020
1-5027
1-5030
1-5035
1-5037
1-5045
1-5046
1-5046
1-5046
1-5045
1-5045
1-5046
Optical
Rotation.- 12° 34'
- 12° 22'
- 12° 46'
- 12° 54'
- 13° 10'
- 12° 36'
- 11° 8'
- 10 ° 4'
- 9° 10'
- 8° 20'
- 7° 45'
- 7° 8'
- 6° 34'
Solubility in 5 Vols.
70 per Cent. Alcohol.Soluble at 40° to 50°
25°
„ 25°
25°
25°
25°
„ 25°
„ 26-5°
„ 29°
32°
35°
38°
44°The refractive index and specific gravity gradually increased whilst(^1) Jour. Ind. Eng. Chem. (1916), 420.