alled "essences," and contain the
concentrated odor of the plant. They usually exist ready-formed, but
occasionally they are obtained by a kind of fermentation, as oil of
bitter almonds and oil of mustard. Some of them consist of carbon and
hydrogen only, as oil of turpentine, from _Juniperus communis;_ oil of
savin, from _Juniperus Sabina;_ oil of lemons and oranges, from the
rind of the fruit; and oil of nerole, from orange flowers. A second
set contain oxygen in addition, as oil of cinnamon, from _Cinnamonum
verum;_ otto or attar of roses, from various species of rose,
especially _Rosa centifolia;_ oil of cloves, from _Caryophyllus
aromaticus_.

Those principally obtained from tropical shrubs and plants are
citronella, oil of oranges and lemons, from the rind of the fruit oil
of cinnamon and cloves, croton oil, &c.

The oil of Sandal or Sanders wood _(Santalum album_), grown on the
Malabar coast, is much esteemed as a perfume. Keora oil, from
_Pandanus odoratissimus_, in Bengal. Oil of spikenard, so highly
prized, on account of its perfume, by the ancients, may be procured in
Sagur, Nepaul, and the mountains of the Himalaya.

956 lbs. of essential oils were imported into Hull in 1850. There were
exported from Ceylon in 1842, 902 cases; in 1843, 138; in 1844, 20; in
1845, 25 cases of essential oils, and in the last two years as
follows:--

1852. 1851.
cases. cases.
Cinnamon oil 17 23
Citronella oil 110 87
Essential oil 72 35

Of chemical, essential, and perfumed oils imported from France, the
quantity is about 35,000 lbs. annually, worth L10,000. The duty is 1s.
per lb. We also imported from France, in 1851, 9,596 cwt. of oil or
spirit of turpentine, worth L14,197, on which a duty of 5s. 3d. per
cwt. is levied.

From Western Australia some distilled oil of the Liptospermum was
shown at the Exhibition, which it is stated may be obtained in any
quantity, and a similar oil produced, by distillation, from the
_Eucalyptus piperita_, a powerful solvent of caoutchouc, evidently
very similar, if not altogether identical, with the oil of cajeput.
The characters of these two oils are much alike and without some care
it is difficult to distinguish them from one another by the odor; the
liptospermum oil has a slight tinge of yellow, its specific gravity is
0.9035; the eucalyptus oil is colorless, and has a density of 0.9145.
It