MAGNOLIACE^E 507
Petroleum oil separates in a nearly pure condition on shaking the
oil with 10 volumes of 90 per cent, alcohol.
As indicating the effect of anise-leaf oil, Umney
l
gives the following
comparative figures for the leaf and fruit oils:—Specific gravity at 15*5°
Optical rotation
Fractionation:—
Below 225° C.
From 225° to 230° C.
Above 230° C.Leaf Oil.
0-9878
+ 1°. 10 per cent.
. 60
. 30
Fruit Oil.
•975 to -990
0 „ - 2°
20 per cent.
65 „
15
The author
2
and J. C. Umney
3
have examined a number of commer-
cial samples, which had abnormal characters, and which had either been
adulterated with fractions of camphor oil, or had had part of the anethol
abstracted.
The samples examined by the author had the following characters :—
Specific gravity at 20°
Refractive index at 20°
Melting-point.
Congealing-point
Optical rotation0-9575 to 0-9740
1-5460 „ 1-5475
12° „ 15°
10-5° „ 12°
+ 0° 15' „ 0° 35'
It will be noticed that the specific gravity is abnormally low, and!
does not correspond with pharmacopoeial requirements, while the melting;
and congealing-points are also very low. The refractive index is lower
than has ever been found for pure aniseed oil, which has a value betweent
1*5530 and 1-5565, or thereabouts. The slight dextro-rotation indicates-
nothing, as some samples of pure star-anise oil are faintly dextro-rotatory.
A large sample from one shipment was examined more fully, and
finally a bulked sample made from a number of the above-described
samples, and fractionally distilled, side by side with a pure anise oil-
The results of this distillation are embodied in the following table :—
Adulterated. Pure.
Specific gravity at 20°
Optical rotation
Refractive index at 20°
Melting-point
Gongealing-point.
Refractive index of 1st 10 per cent.
Melting-point ,,10 „Refractive index of 2nd 10 „
„ „ last 20 ,,
All the immediate fractions had lower refractive indices and lower
melting-points than the corresponding fractions of the pure oil, and the
amount distilling between 225° and 235° was only 69 per cent., against
87 per cent, for the pure oil. The residue of 20 per cent, was less
soluble in alcohol than the corresponding fraction of pure aniseed oiL
The odour of the adulterated oils was characteristic, and quite different
from that of pure oil. These figures proved conclusively that these
samples were not genuine anise oil, and, taken in conjunction with the
peculiar odour and taste, indicate strongly that the adulteration took the
form of the addition of some foreign oil. The most probable adulterant
is some fraction of camphor oil.
1
P. and E.O.R. (1914), 73.
2
Chemist and Druggist (1910), 687.
3
P. and E.O.R. (1910), 236.
0-9720
0°
1-5469
13°
11°
1-5160
- 3° (partial
solidification)
1-5308
1-5403