Counsel Against the Plague

.1478
In Florence
150 p[er] day

[...and] is not apt to inflame and putrefy; especially because they have narrow passages where the poison can pass. Therefore, old men are somewhat safer, although the plague of this year does not regard old men, perhaps because, beyond other malignant constellations, Saturn retrograde was lord of the year. And it is a great wonder that, having fled from Florence, almost the entire populace is dying at a rate of one hundred fifty per day.

Of the signs of the plague. Chapter Four.

By what signs it is demonstrated, through which one may quickly and clearly discern that a fever is pestilential, no one can well declare. So diverse and fallacious is this accident, and this all the doctors confess, especially Avicenna and Rasis. The urine will sometimes be clear, because the humor will not go to the liver. There will be or will appear little fever, because the poison will not be in hot humors or will not go outward; and the infirm will perish. He will seem lightened because nature will have removed from the heart the first assault of the poison; a little later he will perish because he will not remove the second assault, nature being fatigued in the first and the poison being multiplied or turned malignant or brought closer to the heart than before. Almost all make this first improvement, because nature, robust at the beginning, acts immediately.