The animals which feed upon poison have been already[369] mentioned. Some of them, which are harmless of themselves, become noxious if fed upon venomous substances. The wild boar of Pamphylia and the mountainous parts of Cilicia, after having devoured a salamander, will become poisonous to those who eat its flesh; and yet the danger is quite imperceptible by reason of any peculiarity in the smell and taste. The salamander, too, will poison either water or wine, in which it happens to be drowned; and what is more, if it has only drunk thereof, the liquid becomes poisonous. The same is the case, too, with the frog known to us as the bramble-frog. So numerous are the snares that are laid in wait for life! Wasps greedily devour the flesh of the serpent, a nutriment which renders their stings fatal; so vast is the difference to be found between one kind of food and another. In the country, too, of the Ichthyophagi,[370] as we learn from Theophrastus, the oxen are fed upon fish, but only when alive. CHAP. 117.—REASONS FOR INDIGESTION. REMEDIES FOR CRUDITY. The most wholesome nutriment for man is plain food. An accumulation of flavours is injurious, and still more so, if heightened by sauces. All acrid elements are difficult of digestion, and the same is the case if food is devoured greedily, or in too large quantities. Food is also less easily digested in summer than in winter, and in old age than in youth. The vomits which man has invented, by way of remedy for this evil, render the body more cold, and are more particularly injurious to the eyes and teeth. CHAP. 118.—FROM WHAT CAUSES CORPULENCE ARISES; HOW IT MAY BE REDUCED. Digestion during sleep is more productive of corpulence than strength. Hence it is, that it is preferable for athletes to quicken digestion by walking. Watching, at night more especially, promotes digestion of the food. (54.) The size of the body is increased by eating sweet and fatty substances, as well as by drinking, while, on the other hand, it is diminished by eating dry, acrid, or cold substances, and by abstaining from drink. Some animals of Africa, as well as sheep, drink but once every four days. Abstinence from food for seven days, even, is not of necessity fatal to man; and it is a well-known fact, that many persons have not died till after an abstinence of eleven days. Man is the only animal that is ever attacked with an insatiate[371] craving for food. CHAP. 119.—WHAT THINGS, BY MERELY TASTING OF THEM, ALLAY HUNGER AND THIRST.