Olive Oil.—The olive is extensively grown in Southern Europe and in portions of Asia and Africa bordering the Mediterranean Sea. The fruit of this tree yields the oil.
The free fatty acid content of olive oil varies very considerably. Very fine oils contain less than 1 per cent. acidity; commercial oils may be graded according to their free acidity, e.g., under 5 per cent., under 10 per cent., etc., and it entirely depends upon the desired price of the resultant soap as to what grade would be used. The following is a typical sample for use in the production of high-class toilet soap:—
| Saponification Equivalent. | Acidity (as Oleic Acid) Per Cent. | Titre, °C. | Refractive Index at 15° C. |
| 288 | 1.8 | 21 | 1.4704 |
Olive oil should absorb 80 to 83 per cent. iodine.
Olive-kernel oil, more correctly termed Sulphur olive oil.
The amount of free fatty acids is always high and ranges from 40-70 per cent., and, of course, its glycerol content is proportionately variable. The free acidity increases very rapidly, and is, doubtless, due to the decomposition of the neutral oil by the action of hydrolytic ferment.
A representative sample of a parcel tested:—
| Saponification Equivalent. | Acidity (as Oleic Acid) Per Cent. | Refractive Index at 20° C. |
| 298 | 40.96 | 1.4666 |
Palm oil is produced from the fruit of palm trees, which abound along the west coast of Africa. Lagos is the best quality, whilst Camaroons, Bonny, Old Calabar and New Calabar oils are in good request for bleaching purposes.