[De epidemia et peste]

heart. One should not wander through the town, but remain in the house with doors and windows closed with glass or waxed cloth, so that light enters but not the putrid air. Therefore, every stench should be avoided, and good odors should be increased moderately. In summer, however, use things that are always cold, and if in winter one smells something warm or is fumigated with them, such as musk, ambergris, or the like, it will not be an error, as Avicenna says. He teaches how to alter the air with ambergris, incense, aloe wood, and similar things. Secondly, I prove that these aromatic substances do not cause harm. Because stenches are extremely harmful, as has been seen, therefore aromatic substances and good odors will help through the rule: "If the opposite is in the opposite, then the proposed is in the proposed." A reference to the Aristotelian or scholastic principle of contraries. Thirdly, because these things dry the air, which is necessary in a pestilence that comes in the winter. Fourthly, because they comfort the heart and the brain. And if it is said that one must fear the heating of the heart, etc., I answer that they do not overheat, nor do they corrupt the surrounding humors from the heat of the air, nor even from that small smoke or vapor raised from the aromatic substances, but rather they protect against corrupt and putrid air. And if it is said that these warm vapors are a vehicle for putrid air to the heart, it is not true, because even without these, putrid and corrupt air enters the chambers of the heart, because whether we like it or not, we inhale the air.

It remains, therefore, that these things do not cause harm, especially in winter, because this vapor resolved from aromatic substances is small and familiar to nature, and the spirits are refreshed by it, just as is seen in those who suffer from fainting. Therefore, let a fumigation be made first in the morning, and especially for the rich in cold weather, with ambergris, incense, aloe wood, storax, ladanum, saffron, mastic, cloves, and cinnamon, which when it burns, makes a good odor. And sometimes with turpentine and spikenard, with all of these or some of them. If all of these cannot be had, let it be made with lavender,