- N. O. ABOIDE^E 89
Specific gravity at-|5° 0*842
Acid value .30
Saponification value 15
Iodine value .93-2
Apparently portions of the fatty oil were present, having.been me-
chanically carried over during the distillation. The only constituent of
the ( Volatile oil identified with certainty was methyl-nonyl ketone.N. 0.
CALAMUS OIL.This oil is distilled from the rhizome of the sweet flag, Acorus cala-
mus. This plant is a member of a family with aquatic tendencies, and
is probably a native of Asia, although now found largely in Europe.
Although the essential oil obtained from the rhizome is known either
as 01. Acori calami or 01. Calami aromatici, the plant must not, as
Pereira points out, be confused with the Calamus aromaticus described
by Eoyle, which is one of the Andropogon family. The banks of Euro-
pean rivers afford a plentiful supply for the markets, and it is also
-cultivated in damp swamps in India. The fragrance of the plant and
its oil appears to increase as the climate in which it is cultivated is
warmer. Commercial rhizome of European origin is obtainable in the
shops, and occurs as somewhat flattened pieces of about 4 ins. long and
about f of an inch thick. Keeping does not improve it, nor does the
process of decorticating it, as is often done for appearance sake. Many
of the essential oil glands occur in the outer layers of the rhizome, so
that the process of peeling naturally lessens the odour value. Dymock
thus describes the Indian rhizome in his Notes on Indian Drugs : " The
root stock occurs in somewhat tortuous, sub-cylindrical or flattened
pieces, a few inches long and from ^ to 1 in. in greatest diameter.
Each piece is obscurely marked on the upper surface with the scars,
•often hairy, of leaves, and on the under with a zig-zag line of little,
elevated dot-like rings, the scars of roots. The root stock is usually
rough and shrunken, varying in colour from dark brown to orange-
brown, breaking easily with a short, corky fracture, and exhibiting a
pale brown spongy interior. The odour is aromatic and agreeable, the
taste bitterish and pungent." The powdered rhizome is used for sachet
and toilet powder. Dried roots yield from 1/5 to 3
- 5 per cent, of es-
sential oil, whilst the fresh root yields under 1 per cent. Japanese root
which is possibly that of Acorus spurius yields as much as 5 per cent.
The oils do not quite agree in their chemical properties, and that from
the green rhizome has a finer odour than that from the dried. The
chief difference noticeable is that the oil from green root is more soluble
in weak alcohol than that from the dried.
According to Eussell^1 all parts of the plant contain oil, the roots
having the largest percentage. The oils obtained by steam distillation
from the aerial portions, rhizome, and roots possess varying physical
-and chemical constants. The results of fractionation of these oils indi-
cate that the components of each are present in varying amounts, also
ihat these components vary to some extent. The plants experimented
(^1) Jour. Amer. Chem. Soc., 37 (1915), 2387.