I showed this above in Valasca. I shall add other examples. Godescalcus Hollen, an Augustinian, in the Praeceptorium, folio 20, letter A, writes thus:
I know a woman who wished to make a divorce between two people who loved each other mutually, for which she was to be paid. She wrote two unknown characters on little papers, with other pious words, and gave the papers to be carried; and yet no division followed. Second, she wrote these same things on cheese and gave it to them to eat. Then she took a black chicken and divided it down the middle; she offered one part to the Devil with a certain rite of sacrifice, and gave the other part to those two to eat. Then the greatest hatred followed between them, so that one could not see the other.
He adds: “From where did this come, unless because the demon then had his offertory?” So he writes.
I judge that the poet had regard to this kind of harmful magic when he introduces a certain woman saying to the demon:
You can send brothers of one mind into battle.
Andrea Cesalpino, On the Investigation of Demons, chapter 10, writes that witches are accustomed to bury heads and skins of serpents under a threshold or in the corners of a house, in order to reconcile people to hatred. But these little bits are only signs of an agreed pact. For the demon is the author of the harmful magic of hatred. Natural drugs cannot accomplish anything except to affect a human being with dark and troubled blood and a certain grave melancholy; likewise to burn up the humors excessively or induce harmful cold. From this would arise a certain ferocity, peevishness, cruelty, and hatred of humankind in general, such as exists in those who labor under wolf-madness.
Afterward the demon directs this hatred toward a definite person, throwing into the imagination every image suitable for hatred, placing them as if before the eyes, and recalling them to memory with marvelous causes of bitterness, so that when they recur to the mind a person can scarcely fail to be most gravely irritated and inflamed, even against those whom he deeply loves when that disturbance has ceased.
Johann Baptista Codronchus narrates a memorable example of this harmful magic in book 3, chapter 8, On Harmful Magical Diseases:
In the town of Sepino, in the jurisdiction of Naples, there was a certain man named Jacob, whose wife treated him with such great hatred that from the first day on which marriage had been contracted between them, they could not live together, much less be joined with one another. And if at any time Jacob wished to approach his wife, the wife was stirred with such fury and rage that she would sooner throw herself headlong through a window than endure him. When this had been told to a certain religious man, who had been received by them as a guest, he, doubtful about the matter and having difficulty giving credence to it, ordered the woman to be summoned immediately for the sake of testing it. Her husband hid himself in the inner part of the house, lest his presence make the wife refuse to enter.
The woman came. Asked about the cause of her hatred against her husband, she first lamented her lot and miserable fate, and said that she could give no reason for it. Indeed, she said that she burned with such great desire and love for her absent husband that she could not express it in words. But when she wished to approach him to speak with and see him, immediately there appeared to her imagination her husband painted with so many deformities, so many shameful things, and so many horrible monsters, that she would rather undergo death than bear him. She asserted that her whole soul and all the powers and parts of her spirits were borne against her husband as against an offered evil and her own destruction. But when he was absent, she said, she burned with desire for him.
When that good priest, because of the woman’s words, wished to make an experiment, he told the women accompanying her to bind her around the feet and arms with a strong rope around a bed in the form of a cross, so that her husband, with all resistance removed, might have free access to her. For that priest feared that, because of some deformity to be concealed, the wife was pretending herself to be so affected. The wife therefore allowed herself to be bound because of her desire for her husband, asking that her husband be admitted to her. When he entered, no wild beast has ever seemed so monstrous, no beast so savage, no brute so raging and furious as she was. She foamed from the mouth, gnashed with her teeth, twisted her eyes, and her whole body seemed agitated by Furies and full of demons. The women sitting by reported that her belly and stomach seemed to them, as they touched, to be filled with twisted ropes, and that her whole skin seemed reduced as if by whips or blows. There was no end of rage until the husband, exhausted by the struggle and moved by pity for her, went out from there.
At last, after three years, a certain woman practiced in poison-workings, who had taken the marriage of Jacob with that wife grievously and painfully, dissolved the harmful magic which she had committed. Thus Jacob enjoyed his wife and thereafter lived in the greatest peace and calm.
To this belongs the harmful magic of forgetfulness, by which men neglect their wives so that they seem not to remember them. I shall explain the matter by an example, confirmed by the same two witnesses.
In the Tuscan town of San Gimignano, a certain young man loved a witch woman so ruinously that he abandoned his otherwise beautiful and honorable wife, together with his children, and lived with his mistress, forgetful of his own people, until his wife, warned of the harmful magic, went there. After the instrument of the harmful magic had been secretly sought, she found under the roof a toad enclosed in a pot, its eyes sewn shut. When this had been snatched away, and its eyes loosened and afterward burned, the husband immediately remembered his own people, as if waking from sleep, and returned to his wife and children.