On a 17th century Italian dressing table, among the perfume and combs, sat a small glass vial painted with the image of a saint. It was sold as Manna di San Nicola, a common devotional item, and it held a poison blamed for more than 600 deaths. This episode tells the story of Giulia Tofana and the network that sold it to women with no other way out. Marriage was an unbreakable contract, divorce did not exist, and authorities returned fleeing wives to violent husbands. The recipe is traced to Sicily in the early 1630s and to Teofania di Adamo, thought to be Tofana’s mother, who was executed.

Tofana and her associate Gironima Spana carried the formula to Rome and built a ring of six female poisoners with a supply chain running through a priest whose brother was an apothecary. The mixture of arsenic and lead, likely with belladonna, was colorless and tasteless, and four drops given over several days produced what looked like natural illness. The episode follows the ring’s exposure, the crackdown of 1659, and the poison’s long afterlife, from a French murder case to the deathbed fears of Mozart and a modern social media slogan.

• Father Girolamo of the church of Sant’Agnese in Agone supplied the arsenic, obtained through his apothecary brother.
• Sweet tasting sugar of lead is thought to have masked the bitter metallic edge of the arsenic, leaving nothing to notice in wine or soup.
• The slow decline gave a husband time to confess and, more usefully for his wife, to finalize his will before the fourth drop.
• In 1659 five women from the ring were publicly executed in Rome and 40 clients were sentenced to life in prison, while Tofana herself is believed to have died before the arrests.
• In 1791 the ailing Mozart told his wife someone had given him aqua tofana, a claim with no evidence behind it, and the name has resurfaced online as the acronym MATGA.