in escaping to England. La Chaussée was not so fortunate. Altogether ignorant of the fatal mischance which had brought his villanies to light, he did not dream of danger. He was arrested and brought to trial: being put to the torture, he confessed that he had administered poison to the Messieurs d’Aubray, and that he had received a hundred pistoles, and the promise of an annuity for life, from Sainte Croix and Madame de Brinvilliers, for the job. He was condemned to be broken alive on the wheel, and the Marchioness was, by default, sentenced to be beheaded. He was executed accordingly, in March 1673, on the Place de Greve, in Paris.

La Brinvilliers appears to have resided for nearly three years in England. Early in 1676, thinking that the rigour of pursuit was over, and that she might venture to return to the Continent, she proceeded secretly to Liege. Notwithstanding her care, the French authorities were soon apprised of her return; and arrangements were promptly made with the municipality of that city, to permit the agents of the French police to arrest her within the limits of their jurisdiction. Desgrais, an officer of the maréchaussée, accordingly left Paris for that purpose. On his arrival in Liege, he found that she had sought shelter within the walls of a convent. Here the arm of the law, long as it is said to be, could not reach her: but Desgrais was not a man to be baffled, and he resorted to stratagem to accomplish what force could not. Having disguised himself as a priest, he sought admission to the convent, and obtained an interview with La Brinvilliers. He said, that being a Frenchman, and passing through Liege, he could not leave that city without paying a visit to a lady whose beauty and misfortunes were so celebrated. Her vanity was flattered by the compliment. Desgrais saw, to use a vulgar but forcible expression, “that he had got on the blind side of her;” and he adroitly continued to pour out the language of love and admiration, till the deluded Marchioness was thrown completely off her guard. She agreed, without much solicitation, to meet him outside the walls of the convent, where their amorous intrigue might be carried on more conveniently than within. Faithful to her appointment with her supposed new lover, she came, and found herself, not in the embrace of a gallant, but in the custody of a policeman.

Her trial was not long delayed. The proofs against her were abundant. The dying declaration of La Chaussée would have been alone enough to convict her; but besides that, there were the mysterious document attached to the box of St. Croix; her flight from France; and, stronger and more damning proof than all, a paper, in her own handwriting, found among the effects of St. Croix, in which she detailed to him the misdeeds of her life, and spoke of the murder of her father and brothers, in terms that left no doubt of her guilt. During the trial, all Paris was in commotion. La Brinvilliers was the only subject of conversation. All the details of her crimes were published, and greedily devoured; and the idea of secret poisoning was first put into the heads of hundreds, who afterwards became guilty of it.

On the 16th of July 1676, the Superior Criminal Court of Paris pronounced a verdict of guilty against her, for the murder of her father and brothers, and the attempt upon the life of her sister. She was condemned to be drawn on a hurdle, with her feet bare, a rope about her neck, and a burning torch in her hand, to the great entrance of the cathedral of Notre Dame; where she was to make the amende honorable, in sight of all the people; to be taken from thence to the Place de Greve, and there to be beheaded. Her body was afterwards to be burned, and her ashes scattered to the winds.

After her sentence, she made a full confession of her guilt. She seems to have looked upon death without fear; but it was recklessness, not courage, that supported her. Madame de Sevigne says, that when on the hurdle, on her way to the scaffold, she entreated her confessor to exert his influence with the executioner to place himself next to her, that his body might hide from her view “that scoundrel, Desgrais, who had entrapped her.” She also asked the ladies, who had been drawn to their windows to witness the procession, what they were looking at? adding, “a pretty sight you have come to see, truly!” She laughed when on the scaffold, dying as she had lived, impenitent and heartless. On the morrow, the populace came in crowds to collect her ashes, to preserve them as relics. She was regarded as a martyred saint, and her ashes were supposed to be endowed, by Divine grace, with the power of curing all diseases. Popular folly has often canonised persons whose pretensions to sanctity were extremely equivocal; but the disgusting folly of the multitude, in this instance, has never been surpassed.