136 THE CHEMISTEY OF ESSENTIAL OILS
Malabar or Tinnevelly cinnamon, which is also a product of Southern
India.
" Cinnamon has also been cultivated in Java since 1825, the variety
•cultivated having large leaves often 8 ins. long by 5 ins. broad. It is also
.grown in Brazil, and French Guiana and the Seychelles.
" But the cinnamon of all these countries is appreciably different
from Ceylon cinnamon, partly, perhaps, from want of careful cultiva-
tion, and the absence of the acquired skill of the regular cinnamon
peeler, and partly from the age of the shoots or branches used, and
partly also from climatic differences, or the altitude at which the tree
is cultivated. Cinnamon bark in powder, especially in the cheaper
•qualities, requires careful examination. Bark that has been exhausted
by distillation is apparently sometimes used; in other cases powdered
cassia is sometimes substituted for it.
" The oil of cinnamon imported from Ceylon usually contains 10 to
"20 or even 50 per cent, of leaf oil, possibly due to the distillation of the
leaves along with the bark trimmings or chips. The oil distilled in this
country from the imported cinnamon chips, which are not mixed with
the leaves, would naturally be free from leaf oil. The presence of leaf
oil in oil of cinnamon bark can be detected easily by dissolving one drop
•of the suspected oil in five of alcohol and adding ferric chloride,
which will produce a pale green colour with the pure bark oil, whereas
leaf oil, or bark oil adulterated with leaf oil, produces a deep blue
colour."
There is some difference of opinion as to the limit values in specific
gravity and cinnamic aldehyde-content in pure cinnamon bark oils,
and it is also certain that the characters of the oil will differ materially
according to the origin of the bark.
The oil distilled on the continent usually has a higher specific
gravity and aldehyde-content than English distilled oil. Much of the
so-called cinnamon oil of continental origin is undoubtedly adulterated
with artificial cinnamic aldehyde, which would explain these characters,
but oils, probably genuine, with these high figures, appear to owe them
to a different method of distillation from that practised in England.
With these reservations, the characters of pure cinnamon bark oil may
be taken as follows :—English Distilled. Continental Distilled. Seychelles Oil.
Specific gravity.. 0'995 to 1-040 1'020 to T040 0-943 to 0'975
Optical rotation.. 0° „ - 1° 0° „ - 1° - 1° „ - 3°
Refractive index.. 1-5700 „ 1*5850 1-5850 „ 1-5910 1*5280 „ 1-5335
Aldehydes (bisulphite
method)... 53 to 70 per cent. 63 to 76 per cent. 25 to 36 per cent.
Phenols ... 5 „ 10 „ 4 „ 10 „ 6 „ 16 „The oil is usually soluble in 3 volumes of 70 per cent, alcohol, ex-
cept in the case of Seychelles oil, which requires up to 10 volumes.
Umney and Bennett, in a paper read before the British Pharma-
ceutical Conference in 1910,^1 give the following figures for a series of
cinnamon oils, calling attention to the absence of light fractions in the
oils distilled on the Continent:—
No. 1.—Very fragrant, very sweet, but not a normal oil, imported
•direct from Ceylon :—
'P. ani .O.R. (1910), 169.