In those times artificial oils had not been introduced, and hence it is, I suppose, that we find no mention made of them by Cato; at the present day the varieties are very numerous. We will first speak of those[1692] which are produced from trees, and among them more particularly the wild olive.[1693] This olive is small, and much more bitter than the cultivated one, and hence its oil is only used in medicinal preparations: the oil that bears the closest resemblance to it is that extracted from the chamelæa,[1694] a shrub which grows among the rocks, and not more than a palm in height; the leaves and berries being similar to those of the wild olive. A third oil is that made of the fruit of the cicus,[1695] a tree which grows in Egypt in great abundance; by some it is known as croton, by others as sili, and by others, again, as wild sesamum: it is not so very long since this tree was first introduced here. In Spain, too, it shoots up with great rapidity to the size of the olive-tree, having a stem like that of the ferula, the leaf of the vine, and a seed that bears a resemblance to a small pale grape. Our people are in the habit of calling it “ricinus,”[1696] from the resemblance of the seed to that insect. It is boiled in water,[1697] and the oil that swims on the surface is then skimmed off: but in Egypt, where it grows in a greater abundance, the oil is extracted without employing either fire or water for the purpose, the seed being first sprinkled with salt, and then subjected to pressure: eaten with food this oil is repulsive, but it is very useful for burning in lamps. Amygdalinum, by some persons known as “metopium,”[1698] is made of bitter almonds dried and beaten into a cake, after which they are steeped in water, and then beaten again. An oil is extracted from the laurel also, with the aid of olive oil. Some persons use the berries only for this purpose, while others, again, employ the leaves[1699] and the outer skin of the berries: some add storax also, and other odoriferous substances. The best kind for this purpose is the broad-leaved or wild laurel,[1700] with a black berry. The oil, too, of the black myrtle is of a similar nature; that with the broad leaf[1701] is reckoned also the best. The berries are first sprinkled with warm water, and then beaten, after which they are boiled: some persons take the more tender leaves, and boil them in olive oil, and then subject them to pressure, while others, again, steep them in oil, and leave the mixture to ripen in the sun. The same method is also adopted with the cultivated myrtle, but the wild variety with small berries is generally preferred; by some it is known as the oxymyrsine, by others as the chamæmyrsine, and by others, again, as the acoron,[1702] from its strong resemblance to that plant, it being short and branching.