We regarded it as essential to say something of this band of alchemists and 'philosophers' by way of introduction to Louis de Vanens. This young noble of Provence, 'a man of well-knit and graceful figure,' had brilliant connections at court, where he was on a footing of intimacy with the king's dazzling mistress, Madame de Montespan. On the other hand, he was an assiduous visitor to La Voisin, and was even for some time her 'author.' Vanens was the link between the alchemists and the witches. He was devoted to demoniacal practices. His valet, La Chaboissière, declared that one night he had to accompany his master and a cleric into the woods on the outskirts of Poissy, where they searched for treasures with incantations and invocations to the 'spirit.' Vanens was a diabolical character. He was confined at the Bastille in the same room with other prisoners, as the custom was. He had with him a sort of white and tan spaniel. As midnight approached, he recited some prayer over the body of the dog, and went through the ceremony of consecration. Then he took a prayer-book containing a picture of the Virgin, and laid the picture on the back of the dog, saying, 'Avaunt, devil! Behold thy good mistress!' To the remarks of his companions in captivity, he replied: 'Neither God nor the king shall prevent me from doing what I have done.' To gauge the strange and passionate vigour of these superstitions, we must remember that Vanens was in the Bastille, quite aware that these practices might bring him to the stake. We shall see in the sequel the importance of Vanens when we recall the following lines found in the notes of Nicolas de la Reynie: 'To see La Chaboissière again about his reluctance to have written down in his statement, after hearing it read, that Vanens had been concerned in giving Madame de Montespan counsel which deserves that he should be drawn and quartered.' _La Voisin_ To the portraits of Chasteuil the alchemist and of Vanens, we must add that of the most famous of the witches, Catherine Deshayes, known as La Voisin. It was of her that La Fontaine wrote: 'Une femme à Paris faisait la pythonisse.'