104 THE CHEMISTEY OF ESSENTIAL OILS
These figures are in fair agreement with those given for Malabar
oil, but in no way resemble those quoted by Schimmel for Ceylon oil,
which are difficult to understand.
The oils were soluble with a slight opacity in 40 to 45 volumes of
60 per cent, alcohol.
Little difference exists between the two oils. On distillation at
ordinary pressure the oil, which is very rich in esters, in both cases
decomposes partially, and a considerable quantity of free acid distils
over. According to Weber (Annalen, 238, 89), formic and acetic acids
are found in the distillate. Acetic acid is undoubtedly the chief acid
constituent of the esters, but the author is unable to confirm the pre-
sence of formic acid. If it is present, it is only in faint traces. On
distillation under reduced pressure the earlier fractions (the boiling-
point rises gradually until 50 per cent, has distilled over) contain
cineol, but only to the extent of 5 to 10 per cent, of the oil. This
figure is the result of an approximate estimation by means of phos-
phoric acid.
The following figures may be taken as covering most pure samples :—
Specific gravity 0'923 to 0'945
Optical rotation + 24° „ + 48°
Refractive index 1-4620 „ 1-4675
Acid value 1 „ 4
Ester „ 90 „ 150
It is soluble in 2 to 5 volumes of 70 per cent, alcohol.
The oil contains a considerable amount of terpinyl acetate (and
therefore requires at least two hours for complete saponification). The
terpineol was identified as rf-a-terpineol by Schimmel & Co.
1
The ter-
pene terpinene has been stated to be present, but this is not confirmed
by the author, nor by Schimmel & Co. Limonene is probably present
in small amount. Free terpineol is also present.
The oil distilled from the Ceylon wild cardamoms, Elettaria carda-
momum /?, has the following characters :—
Specific gravity 0'895 to 0-906
Optical rotation. + 12° „ + 16°
Acid value 1 „ 3
Ester, 25 „ 75
This oil contains terpinene, sabinene, terpineol and its esters, and a
solid crystalline substance melting at 60° to 61°.
Siamese cardamom oil is distilled from the seeds of Amomum carda-
momum, which are known on the market as camphor seeds on account
of their camphor-like odour. Schimmel obtained 2*4 per cent., which
was semi-solid at the ordinary temperature, and had an odour of cam-
phor and borneol. In order to liquefy the oil it was necessary to warm
it to 42°. Its specific gravity at this temperature was '905, and its
optical rotation + 38° 4'. It required T88 per cent, of KOH to sap-
onify the esters present, and contained alcohols equivalent to 22-5 per
cent, of borneol. It was soluble in 1-2 volumes of 80 per cent, alcohol.
From 800 grms. of the oil 100 grms. of the solid compounds were ob-
tained by centrifugal action. These were examined and found to con-
sist of about equal parts of dextro-borneol and dextro-camphor.
Kameroon cardamom oil is obtained from fruits which are identical
with the Madagascar cardamoms. They are derived from Amomum
1
Bericht, October, 1897, 9.