When poets refer to other great works, people, and events, it’s usually not accidental. Put on your super-sleuth hat and figure out why.
Marie-Madeleine-Marguerite d'Aubray, Marquise de Brinvilliers: Browning doesn't refer to it directly, but this whole poem is based on a true story. The inspiration for "The Laboratory" came from the life of Marie-Madeleine-Marguerite d'Aubray, Marquise de Brinvilliers (try saying that ten times fast!). Madame de Brinvilliers was a French aristocrat in the late seventeenth century who poisoned her father and her brothers so she wouldn't have to share her inheritance. Charming. She was tried and executed in 1676.