In the first place, we take it for granted that moisture is wasted and destroyed by heat, that the drier parts of the nourishment qualified and softened by moisture, are diffused and fly away in vapors.

Secondly, we must by no means suppose that all hunger is a total privation of dry, and thirst of humid nutriment, but only a moderate one, and such as is sufficient to cause the one or the other; for whoever are wholly deprived of either of these, they neither hunger nor thirst, but die instantly.

These things being laid down as a foundation, it will be no hard matter to find out the cause.

For thirst is increased by eating for this reason, because that meat by its natural siccity contracts and destroys all that small quantity of moisture which remained scattered here and there through the body; just as happens in things obvious to our senses; we see the earth, dust, and the like presently suck in the moisture that is mixed with them.

Now, on the contrary, drink must of necessity assuage hunger; for the moisture watering and diffusing itself through the dry and parched relics of the meat we ate last, by turning them into thin juices, conveys them through the whole body, and succors the indigent parts.