CONIFEK.E 45
OILS OF THE GENUS CALLITRIS.
A large number of essential oils derived from various parts of this
important family of Australian pines, have been examined by Baker and
Smith.
1
These authorities summarise a number of interesting points
which their researches on these oils have established as follows :—
The rotation of the terpenes of the oil from the leaves of some species
of Callitris is in the opposite direction to that obtained from the fruits,
even if collected from the same tree.
The acetic ester of geraniol is more pronounced in the leaf oils than
is that of borneol, and it continues to increase in the several members
of one section, until a maximum of over 60 per cent, is reached in the
oil of Callitris Tasmanica.
An ester of terpineol was found in the leaf oil of Callitris gracilis.
The lirnonenes and dipentene occur in the leaf oils, the dextro-
rotatory form reaching a maximum in Callitris arenosa, and the laevo-
form in Callitris intratropica. In these oils is seen a well-defined
illustration of the formation in nature of the two active forms of
limonene in the same plant, as well as the racemic modification.
The leaf oil of Callitris Macleayana contains a constituent which
has a marked resemblance to menthene, and is apparently a member of
that group of hydrocarbons.
The leaf oil distilled from some species of Callitris is comparable
with the best " Pine-needle oils " of commerce.
The oil obtained by steam distillation from the timber of the Callitris
generally, contains the sesquiterpene alcohol Guaiol in some quantity;
the corresponding sesquiterpene is also present.
The characteristic odour of Callitris timber is due to a phenol. This
has distinctive colour reactions and is evidently new. It appears to be
the constituent which renders Callitris timber objectionable to white-
ants. The name Callitrol is proposed for it.
The following species have been examined :—
CALLITRIS EOBUSTA.
The leaves of this tree yielded 0*261 per cent, of oil having a specific
gravity 0*b825, optical rotation + 10*3°, and refractive index 1*4752 at
19 \ The saponification value was 49*59, equal to 17*35 per cent, ester
as bornyl and geranyl acetates. In the cold, with three hours' contact,
the saponification number was 22*78, equal to 7*97 per cent, ester. On
redistilling, practically nothing came over below 155° C. ; between 155°
and 160°, 35 per cent, distilled; between 160° and 165°, 17 per cent.;
between i165° and 200°, 20 per cent.; between 200° and 250°, 12 per cent.
The somewhat large percentage of the oil boiling above 250° indicated
the presence of a sesquiterpene or allied body, but it was not isolated.
The specific gravity of the first fraction at 15° C. = 0*8613; of the
second, 0*8616 ; of the third, 0*8651; of the fourth, 0*907. The rotation,
of the first fraction aD = + 12*2°; of the second, + 12*7°; of the third,
+ 14*15U. With the fourth fraction the light did not pass well, but it
was more highly dextro-rotatory than the third fraction, thus indicating
the presence of the dextro-rotatory bornyl acetate, common to these
oils. The saponification number for the esters of the fourth fraction
1
A Research on the Pines of Australia. Published by the authority of the
Government of the State of New South Wales.