guards, and the other, a boy of fifteen, was just leaving the workhouse of Bicêtre, where he had been placed to 'improve his morals and give him a taste for work.' Marie Bosse was arrested at her own house on the morning of January 4, 1679, in bed with her two sons. Her daughter had just risen. 'There was only one bed, in which they all slept together.' The preliminary inquiry brought to light a crime, the news of which created a sensation almost as great as that evoked by the poisonings by Madame de Brinvilliers. An order in council, dated January 10, instructed La Reynie to proceed against the women Bosse, Vigoureux, and their accomplices. On March 12 an officer set about the arrest of Catherine Deshayes, wife of Antoine Monvoisin, a peddling jeweller. This woman, usually known as La Voisin, was the greatest criminal of whom history has any record. She was arrested as she left the church of Notre Dame de Bonne Nouvelle after hearing mass. In her track La Reynie was to penetrate into a region of crime that the imagination can scarcely conceive. 'Human life is publicly trafficked in,' he wrote in utter consternation: 'death is almost the only remedy employed in family embarrassments; impieties, sacrileges, abominations are common practices in Paris, in the country, in the provinces.' _Sorcery in the Seventeenth Century_ To understand the facts and the characters of the persons we are going to study, we must dwell briefly upon the beliefs of that time--a time when beliefs were dominant influences in the life of men. We know what power religious sentiments had in the seventeenth century--sentiments of an intensity and a simplicity we know little of to-day, and the corruption of which could not but engender the most absurd superstitions. That was the epoch when the sweet Marguerite Alacoque, in her divine ecstasy, exchanged her heart with that of Christ, and wrote in her own blood, under dictation from on high, the contract which ascribed to God these words: 'I constitute thee heiress of my heart and all its treasures for time and eternity; I promise thee that thou shalt only lack succour when I lack power; thou shalt be for ever the well-beloved disciple, the plaything of my good pleasure and the burnt-offering of my love.' And that, too, was the period when Catherine Monvoisin, the terrible sorceress of Villeneuve-sur-Gravois, found numerous and ardent followers.