Counsel Against the Plague

the humors, and to fortify the heart. Note that to understand correctly what I mean when I say that vapor is poisonous, you should not believe it is poison in its own proper form and whole

Note this?

nature—for then all men would fall ill—but rather it is of such a quality that it easily becomes poison; and it becomes poison in the true sense when, within the human body, the humors putrefy and boil over on its account to a certain degree. This commonly occurs on the third day, and sometimes sooner, especially where superfluous humors abound, particularly blood and bile. And when it becomes poisoned, it takes on the nature of quicklime or arsenic, and its effects are to putrefy, to gnaw, and to burn, both within and without. Therefore, it is always necessary to resist these three effects, especially from within.

Whence pestilence arises and where it reigns.

Chapter Two.

This poisonous vapor is created in the air, in the more general pestilences, by malignant constellations, especially by the conjunctions of Mars with Saturn in the human signs, and by eclipses of the luminaries, as in the present plague of 1478 and of