306 THE CHBMISTEY OF ESSENTIAL OILS
largely influenced, as are most of the plants of this natural order, by
variations in soil and climate, and the marked differences in English
and foreign oils is more than can be explained by care in the method
•of production. The plant is grown in a few places in England, but
English rosemary oil is almost negligible as an article of commerce, the
.greater part of the commercial oil being produced in the south of
Europe. Several countries on the Mediterranean littoral produce small
quantities, but after the south of France the chief source of the oil is
the Dalmatian Islands. Spain, however, now produces a quantity of
rosemary oil. The Dalmatian produce is chiefly brought into com-
merce vid Trieste, and this is the oil usually known in trade as Italian
rosemary oil. The English oil is by far the most valued, and commands
an infinitely higher price than the foreign oil. The Italian (Dalmatian)
and Spanish oil are the least valuable. In England and the south of
France rosemary is distilled as quickly as possible after it is cut, and
in the same manner as lavender flowers. Care is taken to exclude the
woody parts of the plant, as not only do these take up unnecessary
room in the stills, but also yield a less valuable oil. The best oil is that
which distils over during the first hour of the process. The finest
French oil comes from the departments Gard and H6rault, and the
neighbourhood. The supply of oil from the Dalmatian Islands is some-
what irregular, and, according to Schimmel & Co., the reason of this
is that the rosemary woods, as they are called, are municipal property,
and are leased to the peasants and distillers, but with an effective con-
trol as to harvesting. This follows a regular rotation, the general crop
being gathered in one year and very sparing crops for the next two
years. The richest plants grow on the island of Solta, but the success-
ful cultivation of vineyards has nearly replaced the rosemary industry.
A little is cultivated on the island of Lissa, but the majority comes from
Lesina. The total production of these islands varies from 15,000 to
50,000 Ib. per annum. The plants are usually sun-dried before distilla-
tion, and the process is carried out in very primitive apparatus,
which facts possibly account largely for the inferior quality of the oil.
The adulteration practised on this oil appears to commence at Trieste,
and not on the islands. The usual adulterants are turpentine and
petroleum oils, although the finer qualities are at times adulterated with
spike oil.
Spanish rosemary oil is now largely employed in cheap perfumery,
but its odour is not sufficiently fine for high grade work. This is, no
doubt, to some extent due to the fact that other Labiate plants,
especially Lavandula spica and Salvia lavandufolia grow in profusion
with or near the rosemary plants, and are cut with the last named, so
that the oil is frequently a mixture of Labiate oils in which rosemary
predominates.
Kosemary oil of excellent quality is also produced in considerable
quantity in southern Tunis, notably in the Bled. The Tunisian oil is
far softer than Spanish oil, although perhaps not quite so fine as the
best French distillates.
The English market takes something like 50,000 kilos of rosemary
oil per annum, while America and Australia are steadily increasing
their demands. French continental production, on the contrary, is
restricted more and more, for the cost of collection and distillation is
becoming too great for remunerative working. Whole ranges of hills in