Now that bulimy is not hunger but a faintness, is manifest from all laboring beasts, which are seized with it very often through the smell of dry figs and apples; for a smell does not cause any want of food, but rather a pain and agitation in the stomach.
These things seemed to be reasonably well urged; and yet it seemed that much might be said for the contrary opinion, and that it was possible enough to maintain that bulimy ariseth not from condensation but rarefication of the stomach.

For the spirit which flows from the snow is nothing but the aether and finest fragment of the frozen substance, endued with a virtue of cutting and dividing not only the flesh, but also silver and brazen vessels; for we see that these are not able to keep in the snow, for it dissolves and evaporates, and glazes over the outmost superficies of the vessels with a thin dew, not unlike to ice, which this spirit leaves as it secretly passes through the pores.
Therefore this piercing spirit, like a flame, seizing upon those that travel in the snow, seems to burn their outsides, and like fire to enter and penetrate the flesh.

Hence it is that the flesh is more rarefied, and the heat is extinguished by the cold spirit that lies upon the superficies of the body; therefore the body evaporates a dewy thin sweat, which melts away and decays the strength.

Now if a man should sit still at such a time, there would not much heat fly out of his body.

But when the motion of the body doth quickly heat the nourishment, and that heat bursts through the thin skin, there must necessarily be a great loss of strength.