get a pardon for her. Ste. Croix next died suddenly, in consequence, it is said, of his accidentally dropping a glass mask which he wore when compounding his poisons. This story, says Michelet, is a fable. A case of poisons in packets was found in his rooms, each neatly labelled with its effects. These, it was alleged, were addressed to the marchioness, who managed to escape to England, Penautier giving her letters of credit, says Michelet. Michelet says the packets of poison were addressed to Penautier. The marchioness was soon after taken at a convent at Liège by a detective who, pretending to be an Abbé, made love to her and induced her to go for a walk with him, when lie handed her over to his men, who took her to Paris. She was tortured (only formally, says Michelet), convicted, marched to Notre Dame with a rope round her neck to make the "amende honorable," then decapitated, and her body burned.
One of the witnesses at her trial declared that the marchioness once showed her a little box containing some white stuff, and said there were a number of successions in that little parcel. The witness said she was the daughter of an apothecary and recognised that the substance shown her was sublimate.
It has been discussed by experts whether the poison on which Ste. Croix and his mistress chiefly relied was arsenic or sublimate. Most likely it was arsenic. A certain Guy Simon, an apothecary, was employed to experiment with it, and to discover its composition if possible. His report is worth quoting at some length as an illustration of the condition of toxicological science at that period, and incidentally of the simple faith in the almost miraculous powers of the poisoners which evidently possessed all classes at that time.
