Psychic treatment was not unknown. "Music hath charms to soothe a savage breast"; well, medieval Jews applied this cure quite literally to people who had gone out of their minds, and it was believed that the Alpdrücken, who were especially susceptible to the charms of music, could be seduced by its sweet strains to vacate the body of a demoniac. Frightening a patient was another sovereign remedy. An invalid afflicted with chills was startled out of his ailment with the news that his friend had died suddenly, and in an even more wonderful cure, a man who had been eviscerated by a sword thrust groaned so lustily when he beheld what purported to be the slaughter of his children, that his bowels were drawn back into his body, and it was possible to sew up the wound and save his life. In fact, magic cures and incantations were occasionally permitted by rabbis not because of their direct effect upon the disease, but in order to set a superstitious patient's mind at ease.
One of the most widespread medical superstitions is the homeopathic doctrine, similia similibu curantur. The English "hair of the dog that bit you" is matched by the Mishnaic "lobe of the liver" as a remedy for a bite. Maharil is credited with the view that "we may not employ any of the cures and charms given in the Talmud, for we no longer know how to apply them correctly . . . . except the one found in Shab. 67a: 'When a bone sticks in one's throat he should place a similar bone on his head and say, One, one, gone down, swallowed, gone down, one, one.' This cure is tested and proven, and is therefore the only one that may be used."
From: Joshua Trachtenberg, Jewish Magic and Superstition, A Study in Folk Religion (1939), p. 196.
NOTE: Rabbi Trachtenberg’s book, which belonged to my mother, is considered a pioneering work and a classic in its field. I don’t think I’ll ever fully understand all the things that were on her mind. I am very grateful to own her library. "Alpdrücken," by the way, is the German word meaning "nightmares," literally "elf-pressure."