(6.) According to him, the best method of preserving olives is to put the orchites and the posia, while green, in a strong brine, or else to bruise them first, and preserve them in mastich oil.[1684] The more bitter the olive, he says, the better the oil; but they should be gathered from the ground the very moment they fall, and washed if they are dirty. He says that three days will be quite sufficient for drying them, and that if it is frosty weather, they should be pressed on the fourth, care being taken to sprinkle them with salt. Olives, he informs us,[1685] lose oil by being kept in a boarded store-room, and deteriorate in quality; the same being the case, too, if the oil is left with the amurca and the pulp,[1686] or, in other words, the flesh of the olive that forms the residue and becomes the dregs. For this reason, he recommends that the oil should be poured off several times in the day, and then put into vessels or cauldrons[1687] of lead, for copper vessels will spoil it, he says. All these operations, however, should be carried on with presses heated and tightly closed,[1688] and exposed to the air as little as possible—for which reason he recommends that wood should never be cut there, the most convenient fuel for the fires being the stones of the berries. From the cauldron the oil should be poured into vats,[1689] in order that the pulp and the amurca may be disengaged in a solidified form: to effect which object the vessels should be changed as often as convenient, while at the same time the osier baskets should be carefully cleaned with a sponge, that the oil may run out in as clean and pure a state as possible. In later times, the plan has been adopted of invariably crushing the olives in boiling water, and at once putting them whole in the press—a method of effectually extracting the amurca—and then, after crushing them in the oil-press, subjecting them to pressure once more. It is recommended, that not more than one hundred modii should be pressed at one time: the name given to this quantity is “factus,”[1690] while the oil that flows out at the first pressure is called the “flos.”[1691] Four men, working at two presses day and night, ought to be able to press out three factuses of olives. CHAP. 7. (7.)—FORTY-EIGHT VARIETIES OF ARTIFICIAL OILS. THE CICUS-TREE OR CROTON, OR SILI, OR SESAMUM.