Catherine Deshayes La Voisin (1640-1680) began her career as a fortune-teller, but quickly expanded her services to help make her client's fortunes come true. Indulging in both alchemy and black masses, she concocted a particularly subtle and effective poison that had no smell and left no trace. She employed it using an array of trick jewelry built with hidden compartments. Catherine had no love for her husband, nor sons for that matter, and was said to have attempted (or at least plotted) to poison them.*
* Must have been a relaxing home to grow up in.
Her daughter, Marguerite Monvoisin, on the other hand, seems to have joined in Catherine's plots, the most famous of which was a series of scandals known as the Affair of the Poisons. According to certain information collected by the authorities tasked with unmasking this conspiracy, La Voisin and a certain Madame de Montespan (once the King's official mistress) plotted against King Louis XIV. La Voisin was convicted of the conspiracy and on February 22, 1680, she was condemned to death and burned at the Place de la Grève in Paris. Her daughter survived to carry on the family traditions.**
** What an inspiring story of hope against the odds.