Round the turn of the 15th century, near Florence, Italy, there was an essential oil vendor. This husband and wife shop's customers were generally wealthy. There was a plague going around among the poorer citizens. One wealthy customer came to the shop in draping gloves and a large conical mask asking for a specific oil that could prevent the plague. The couple knew where to get this oil in the far north. When they arrived at the village that produced this special oil they found only a very small amount to buy, at any price. A young man told the couple of another way to prevent the plague and he took them to see his mother that knew what to do. Long story short, she used dirty water from the people that were sick to make crackers. If you ate a cracker every day for 5 days you wouldn't get sick. They get back to Florence, the husband gets killed over the supposed cure oil, and the wife if on her own. The customers never came back. She made the crackers instead and the poor people became her customers and she became a hero for saving them from the plague. The government in Rome heard about her cure so they sent soldiers to bring her to Rome to explain this to the scholars and other experts. They killed her.