Problemata Aristotelis

But for those whose body is looser, it happens that when fevers start in these people, they transition into heat, since the whole body is more occupied by humors in these people than in those whose bodies consist of solid matter. And from the coldness of the season, the humors in their body, being compressed, grow hot and fevers arrive. For fever is the heat of the whole body overcoming [the system], and if the same is intensified by too much humor, heat can be produced.

Why does a pestilential year invade when the sun excites much vapor from the earth? Is it because a humid year with rains necessarily signifies that the earth must be soaked? It happens, therefore, that just as if one lives in swampy and heavy places, the body also necessarily abounds with many waste products at that time, so that they have the material for falling ill during the summer.

Why does a heavy year arrive when there is an abundance of tiny frogs that represent the appearance of toads? Is it because everything is accustomed to abound in a place suitable for its nature? Thus, a species of living creature of this kind, since it is humid by nature, indicates a humid and rainy year for that very reason. Years of this kind are undoubtedly heavy. For those whose bodies have been made overly humid are therefore pressed by many waste products, which are the causes for diseases to arise.

Why do dry southern winds that do not contain any moisture usually create fevers? Is it because they excite a foreign heat and humor? For they are by their very nature humid and hot, for which reason a fever is joined [to the body], for it is such that it cannot arise except through the excess of those two qualities. When, therefore, southern winds lack rain, it is necessary that our bodies be affected in such a way. But when rain is present with the winds, it cools us with water; yet it is certain that the southern winds which the sea has sent forth are beneficial to plants. For, cooled by the benefit of the sea, they arrive against rust original: "eruginem" — likely referring to plant blight or mildew, which consists of foreign humor and heat.