A similar error, too, is committed by those who keep the olives, when gathered, upon a layer of boards, and do not press the fruit till it has thrown out a sweat; it being the fact that every hour lost tends to diminish the oil and increase the amurca: the consequence is, that, according to the ordinary computation, a modius of olives yields no more than six pounds of oil. No one, however, ever takes account of the quantity of amurca to ascertain, in reference to the same kind of berry, to what extent it increases daily in amount. Then, again, it is a very general error[1664] among practical persons to suppose that the oil increases proportionably to the increased size of the berry; and more particularly so when it is so clearly proved that such is not the case, with reference to the variety known as the royal olive, by some called majorina, and by others phaulia;[1665] this berry being of the very largest size, and yet yielding a minimum of juice. In Egypt,[1666] too, the berries, which are remarkably meaty, are found to produce but very little oil; while those of Decapolis, in Syria, are so extremely small, that they are no bigger than a caper; and yet they are highly esteemed for their flesh.[1667] It is for this reason that the olives from the parts beyond sea are preferred for table to those of Italy, though, at the same time, they are very inferior to them for making oil. In Italy, those of Picenum and of Sidicina[1668] are considered the best for table. These are kept apart from the others and steeped in salt, after which, like other olives, they are put in amurca, or else boiled wine; indeed, some of them are left to float solely in their own oil,[1669] without any adventitious mode of preparation, and are then known as colymbades: sometimes the berry is crushed, and then seasoned with green herbs to flavour it. Even in an unripe state the olive is rendered fit for eating by being sprinkled with boiling water; it is quite surprising, too, how readily it will imbibe sweet juices, and retain an adventitious flavour from foreign substances. With this fruit, as with the grape, there are purple[1670] varieties, and the posia is of a complexion approaching to black. Besides those already mentioned, there are the superba[1671] and a remarkably luscious kind, which dries of itself, and is even sweeter than the raisin: this last variety is extremely rare, and is to be found in Africa and in the vicinity of Emerita[1672] in Lusitania.