Chemistry of Essential Oils

122 THE CHEMISTEY OF ESSENTIAL OILS

is converted into a glycol, C 10 H 18 O 8 , which, when benzoated by Schotten-
Baumann's method, yields a solid benzoate, melting-point 136° to 137°.
According to Schimmel & Co., normal American worm-seed oil contains
from 62 to 65 per cent, of ascaridol, and about 22 per cent, of cymene.
Light oils of inferior quality, due probably to the quality of the material
distilled, having a specific gravity about 0942, contain from 45 to 50
per cent, of ascaridol and about 38 per cent, of hydrocarbons. II
The oil is used as an anthelmintic.
E. K. Nelson
1
has recently investigated the changes taking place in
this oil on keeping. He points out that this oil increases in specific
gravity and decreases in optical rotation after being kept at ordinary
temperatures for a year. If kept in an ice-chest the changes are not so
marked. The following table shows the changes in four samples of the
oil kept for a year at room temperature, and in a refrigerator:—
Fresh.
At 25°. 1. 2. 2. 4.
Specific gravity... 0-9691 0-9700 0-9550 0-9584
Rotation - 5-4° - 6-2° - 88° - 63°
Refractive index... 1-4726 1-4723 1-4726 1-4725
Refrigerator.
Specific gravity... 09700 09711 09590 09595
Rotation - 5-3° - 59° - 8'6° - 6'1°
Refractive index... 1-4740 1-4740 1-4743 14740
Room Temperature.
Specific gravity... 0'9703 0-9804 0-9838 0'9600
Rotation - 5'2° - 5-5° - 66° - 6'1°
Refractive index... 14745 14750 1-4770 1*4746
Nelson finds that when ascaridol suffers rearrangement, either by
heating or by treatment with ferrous sulphate, there are two other
bodies formed besides the glycol described by Schimmel. One of these
is also a glycol, which he terms /?-glycol, to distinguish it from the
other one. It has the formula C 10 H 18 O 3 , and is decomposed with the
formation of thymol on warming with dilute sulphuric acid. The third
substance is an erythrite melting at 128° to 130°, of the formula C 10 H 20 O 4 ,
which when boiled with dilute sulphuric acid yields a ketone with a
strong menthone odour, and a phenolic body melting at 80° to 81°. The
ketone yields a semi-carbazone melting at 182° to 184°. It is probably
an isomeric menthenone, or a mixture of several isomers.
2

LAURACE^E

OF OP CASSIA
This oil is distilled from the leaves, twigs, and other parts of \the
plant Cinnamomum cassia, which is probably a native of Cochin China,
but which is chiefly cultivated in China proper, the three chief districts
being Taiwu (Lat. 23° 34' N., Long. 110° 18' E.), in the Kwangsi pro-
vince; Lukpo (Lat. 23° 6' N., Long. 112° 24' E.), and Loting (Lat. 22°
52' N., Long. 111° 8' E.), both in the Kwangtung province. Much con-
fusion and mystery existed till recently in regard to the exact botanical
source of the plant and the nature of the oil and the methods of its
distillation, etc., which were largely caused by the shameful adultera-
tion by the Chinese. The following details furnished by actual

(^1) U.S.A. Dept. of Agriculture, Bulletin, No. 109..
(^2) In a still later publication (P. and E. O. R. (1920), from J. Amer. Chem. Soc.)
9.
Nelson deals with the distillation of this oil. An abstract of this paper will be found
in the Appendix at the end of this volume.