LA VOISIN. CATHERINE MONVOISIN, known as "La Voisin" (d. 168o), French sorceress, whose maiden name was Catherine Deshayes, was one of the chief personages in the famous affaire des poisons, which disgraced the reign of Louis XIV. Her husband, Monvoisin was a jeweller, and she practised chiromancy and face reading. She gradually added the practice of witchcraft, in which she had the help of a renegade priest, Etienne Guibourg, whose part was the celebration of the "black mass." She practised medicine, especially midwifery, procured abortion and provided love pow ders and poisons. Her chief accomplice was one of her lovers, the magician Lesage, whose real name was Adam Coeuret. The great ladies of Paris flocked to La Voisin, who accumulated enor mous wealth. Among her clients were Olympe Mancini, comtesse de Soissons, who sought the death of the king's mistress, Louise de la Valliere; Mme. de Montespan, Mme. de Gramont (la belle Hamilton) and others.
In April 1679 a commission appointed to inquire into the subject and to prosecute the offenders met for the first time. Its pro ceedings, including some suppressed in the official records, are preserved in the notes of one of the official rapporteurs, Gabriel Nicolas de la Reynie. The revelation of the treacherous intention of Mme. de Montespan to poison Louis XIV. and of other crimes,
planned by personages who could not be attacked without scandal which touched the throne, caused Louis XIV. to close the chambre ardente, as the court was called, on Oct. I, 1680. It was reopened on May 19, 1681 and sat until July 21, 1682. Many of the culprits, Marie Anne Mancini, duchess of Bourbon, and Madame de Mon tespan among others, escaped through private influence. Some hundred prisoners, among them the infamous Guibourg and Lesage, escaped the scaffold through the suppression of evidence insisted on by Louis XIV. and Louvois. Some innocent persons were imprisoned for life because they had knowledge of the facts. La Voisin herself was executed at an early stage of the proceed ings, on Feb. 20, 1680.
See F. Ravaisson, Archives de la Bastille, vols. iv.—vii. (187o-74) ; the notes of La Reynie, preserved in the Bibliotheque Nationale; F. Funck-Brentano, Le Drame des poisons (1899) ; A. Masson, La Sorcellerie et to science des poisons au XVIle siecle (1904). Sardou made the affair a background for his A ffaire des poisons (29o7). There is a portrait of La Voisin by Antoine Coypel, which has been often reproduced.