In 1837 there were 11,526 acres of ground under cultivation with olives in Southern Illyria, which yielded 261,800 gallons.  Olives and sumach form the principal crops of the landholder.  I have not been able to get any recent correct statistics of the culture and produce.  The oil of Istria is considered equal to that of Provence.  The stones and refuse are used there for fuel.  The olive is also extensively cultivated in the Quarnero Islands, especially Veglia and Cherso, and in Corfu.  There were in 1836, 219,339 acres under cultivation in the Ionian Islands, producing 113,219 barrels.  The olive is gathered there in December.  The average price of the barrel of olive oil was 48s. 3d.  Nearly two millions of gallons of olive oil were exported from Sicily in 1842.  Naples alone shipped five millions of gallons in 1839, and about 2,500 cwts. of oil is shipped annually from Morocco.  Russia imports about 500,000 poods (40 lbs. each) of olive oil annually.

“Provence oil, the produce of Aix, is the most esteemed.  Florence oil is the virgin oil expressed from the ripe fruit soon after being gathered; it is imported in flasks surrounded by a kind of network formed by the leaves of a monocotyledonous plant, and packed in half chests; it is that used at table under the name of salad oil.  Lucca oil is imported in jars holding nineteen gallons each.  Genoa oil is another fine kind.  Galipoli oil forms the largest portion of the olive oil brought to England, it is imported in casks.  Apulia and Calabria are the provinces of Naples most celebrated for its production; the Apulian is the best.  Sicily oil is of inferior quality; it is principally produced at Milazzo.  Spanish oil is the worst.  The foot deposited by olive oil is used for oiling machinery, under the name of’ droppings of sweet oil.’”—­("Pereira’s Materia Medica.”)

The manufacture of olive oil in Spain has undergone very considerable improvement during the last few years; in particular, the process for expressing the oil has been rendered more rapid and effectual by the introduction of the hydraulic press, and thus the injurious consequences which resulted from the partial fermentation of the fruit are avoided.

There are four different kinds of oil known in the districts where it is prepared.

1. Virgin oil—­A term which is applied, in the district Montpellier, to that which spontaneously separates from the paste of crushed olives.  This oil is not met with in commerce, being all used by the inhabitants, either as an emollient remedy, or for oiling the works of watches.  A good deal of virgin oil is, however, obtained from Aix.

2. Ordinary oil.—­This oil is prepared by pressing the olives, previously crushed and mixed with boiling water.  By this second expression, in which more pressure is applied than in the previous one, an oil is obtained, somewhat inferior in quality to the virgin oil.

3. Oil of the infernal regions.—­The water which has been employed in the preceding operation is in some districts conducted into large reservoirs called the infernal regions, where it is left for many days.  During this period, any oil that might have remained mixed with the water separates and collects on the surface.  This oil being very inferior in quality, is only fit for burning in lamps, and is generally locally used.