A description of this laboratory has been left us. The chamber was high up in the tower, with communicating passages in various directions,—to the large tower and also to the basement and, as is said, to the oubliettes and the secret passageway to the Crume and so outside the château. The laboratory occupied the full diameter of the tower; an immense chimney was on one side of the room, in which was placed the furnace where the mutilated bodies of many of the dead infants were consumed. The chamber had but two windows, one to the north the other to the south, both high up in the wall, both capable of being closed and darkened by solid shutters.
Lemire says (p. 27):
“In the highest chamber of the small tower, he [Gilles] had installed a chemical [alchemy] laboratory and there employed his three sorcerers, one French, one English or Picardian, and one Italian”;
And he describes with minutest detail the apparatus employed (p. 28):
“What Gilles desired was that Prelati should make gold, whether by science, by magic, by the intervention of the devil, or by these means united. He attempted the transmutation of metals into gold. He distilled into retorts different liquids destined to dissolve the mineral substances after certain formulas of magic repeated under the invocation of demons. Prelati declared to Gilles that to make these operations successful required the addition of the hearts, hands, or eyes, but above all the blood, of young children. The blood was to be used in tracing the magic circles and figures.”
Lemire believes (p. 30) that Prelati employed the secrets of chemical art, sulphur and phosphorus and similar substances, in forming fiery serpents to deceive Gilles:
“Frogs and serpents, inoffensive but frightful in appearance, a leopard which was naught else than a large dog with bristling hair, cries of beasts, groans, sounds of trumpets; these were the apparatus employed in the scenes of invocation.”
Then he tells (p. 31) how, to furnish victims for these magicians, Gilles carried on his abduction of children, choosing the little peasants who would not be missed, or whose parents would not be likely, from poverty, to pursue the search.
Apparently the first step, at least the first step made public, against Gilles de Retz, charging him with crime, and the first paper forming part of the ecclesiastical record in the archives of the Department of Loire-Inférieure, is the “Declaration of Infamy against Gilles de Retz by the Bishop of Nantes, July 30, 1440.” It was in Latin:
“To all to whom these present letters shall come, Jean, by the permission of the holy apostolic see, Bishop of Nantes, with full assurance of salvation through our Lord and Saviour, salute those present:
“We hereby make known by visiting in person the parish of the Holy Mary at Nantes, in which is built the house or château vulgarly called “la Suze,” the frequent habitation of Gilles de Retz hereinafter described, a parishioner of this church and of other parish churches designated further on. Upon public rumour and on the numerous reports that have come upon us by the denunciatory clamour of Agatha, wife of Denis de la Mignon; of Donété, widow of the defunct Regnaud Donété of St. Marie; of Jean Guibert and his wife of St. Vincent; of the widow Eonnet Kerguen of St. Croix, Nantes; of Jeanne, wife of Jean Darell of St. Similien near Nantes; of Theophanie, wife of Eonnet le Charpentier of St. Clement outside the walls; fortified by the depositions of the synodical witnesses of these churches and by men who, thanks to their probity and their well known prudence, are above suspicion, and who, in the course of our pastoral visit in the same churches, we ourselves have interrogated with the greatest care upon the facts below indicated, or of still others pertaining to the duty of the bishop in his pastoral visits, we have discovered, and the depositions of the witnesses have proved to us, among other things, that Gilles de Retz, our subject and justiciable, by himself or by certain men his accomplices, has strangled, killed, and inhumanly massacred a very large number of infants; that he has committed upon them crimes against nature; that he has made, or has caused to be made, numerous horrible invocations of demons; he has made to them sacrifices and offerings, and has passed a compact with them, without counting other crimes, numerous and enormous, all of which belong within our jurisdiction; and, finally, by several other visits made by us or by the Commissary acting in our name, we know that Gilles de Retz has perpetrated and committed these crimes and still others, within the limits of our diocese.
“For which cause he was, and is now, and publicly for the knowledge of all, rendered infamous towards all grave and honest men. And to the end that no person shall have doubt upon this subject, we have ordained, or fixed, or caused to be fixed, our seal to these present letters.
“Given at Nantes, the day before the last of July, in the year of our Lord, 1440.
“By the command of Monseignior, Bishop of Nantes.
(Signed) “J. Petit.”