The oil of the olive is prevented from getting[1673] thick and rancid by the admixture of salt. By making an incision in the bark of the tree, an aromatic odour may be imparted[1674] to the oil. Any other mode of seasoning, such, for instance, as those used with reference to wine, is not at all gratifying to the palate; nor do we find so many varieties in oil as there are in the produce of the grape, there being, in general, but three different degrees of goodness. In fine oil the odour is more penetrating, but even in the very best it is but short-lived. CHAP. 5. (4.)—THE NATURE OF OLIVE OIL. It is one of the properties of oil to impart warmth to the body, and to protect it against the action of cold; while at the same time it promotes coolness in the head when heated. The Greeks, those parents of all vices, have abused it by making it minister to luxury, and employing it commonly in the gymnasium: indeed, it is a well-known fact that the governors of those establishments have sold the scrapings[1675] of the oil used there for a sum of eighty thousand sesterces. The majesty of the Roman sway has conferred high honour upon the olive: crowned with it, the troops of the Equestrian order are wont to defile upon the ides of July;[1676] it is used, too, by the victor in the minor triumphs of the ovation.[1677] At Athens, also, they are in the habit of crowning the conqueror with olive; and at Olympia, the Greeks employ the wild olive[1678] for a similar purpose. CHAP. 6. (5.)—THE CULTURE OF THE OLIVE: ITS MODE OF PRESERVATION. THE METHOD OF MAKING OLIVE OIL. We will now proceed to mention the precepts given by Cato[1679] in relation to this subject. Upon a warm, rich[1680] soil, he recommends us to sow the greater radius, the Salentina, the orchites, the posia, the Sergian, the Cominian, and the albicera;[1681] but with a remarkable degree of prudence he adds, that those varieties ought to be planted in preference which are considered to thrive best in the neighbouring localities. In a cold[1682] and meagre soil he says that the Licinian olive should be planted; and he informs us that a rich or hot soil has the effect, in this last variety, of spoiling the oil, while the tree becomes exhausted by its own fertility, and is liable to be attacked by a sort of red moss.[1683] He states it as his opinion that the olive grounds ought to have a western aspect, and, indeed, he approves of no other.