The “influenza” of Saturn brings melancholy: On one occasion, Galileo was called as an expert medical witness in a trial to testify about the physical effects of melancholy. In humoral medicine, the human body, like other bodies beneath the Moon, is made of the four sublunar elements: earth, water, air and fire. In the human body, these four elements give rise to the four “humors”: hot and moist make sanguine (blood); hot and dry make choler (bile); cold and moist make phlegm; cold and dry make melancholy (black bile). Health prevails when the four humors are tempered in harmony. Persons possess choleric, melancholic, phlegmatic or sanguine temperaments when their distinctive balance is inclined toward one or other particular humor. Planetary and stellar influences affect humoral balance, so one must take steps, for instance, not to catch the melancholic “influenza” of Saturn when it ascends the night sky.