‘When I was grown up,’ said Marguerite Monvoisin, ‘my mother was no longer reluctant to trust me, and I was present at this sort of mass, and saw that the lady was stark naked on the mattress, with her head hanging down, supported by a pillow on an overturned chair, the legs too hanging over, a napkin on the belly, a cross on the napkin, and the chalice on the belly.’ She adds that this lady was Madame de Montespan. ‘At the mass of Madame de Montespan,’ said Marguerite in the course of another examination, ‘a child was presented which apparently had been prematurely born, and it was put into a basin. Guibourg cut its throat, poured the blood into a chalice, and consecrated it with the wafer, finished his mass, then proceeded to take the child’s entrails. My mother next day carried the blood and wafer to Dumesnil to be distilled, in a glass vessel which Madame de Montespan took away.’ These facts were confirmed on October 23, 1680, by the confrontation of Marguerite Monvoisin with Guibourg—with this variation, that Guibourg tried to shuffle on to La Voisin the butchery of the child.
‘Guibourg said that it was not true that he had opened the child, because it would have stained his alb: he found the child already opened.
‘The girl Voisin, on the contrary, declared that he cut open the heart himself, took out some clotted blood, and put it into the vessel into which the other blood and the rest had been put, which Madame de Montespan took away; and that to make the clotted blood go in, a common glass was broken, which, with its foot knocked off, was made to act as a funnel.
‘Guibourg said that he did not open the child’s stomach, but that having found it open, he did in fact draw out the entrails and open the heart to get out the blood that was in it, and that he put it into a crystal vase with some portions of the consecrated wafer: the whole was carried off by the lady on whose body he had said mass; and that he always believed the lady was Madame de Montespan.’
This picture is fraught with so much horror that we could not bring ourselves to admit its authenticity if the evidence of Marguerite Monvoisin and the Abbé Guibourg were not corroborated by confessions extorted from other accomplices of these crimes, who were arrested at different dates and examined separately—Lesage, Lacoudraye, Delaporte, Vertemart, Françoise Filastre, the Abbé Cotton—confirmed by the declarations of several witnesses who had picked up, before the trial, fragments of talk which escaped the accused. La Reynie emphasises the fact that the declarations of Lesage and the girl Monvoisin were made at an interval of sixteen months, and without their having had any opportunity during those months of communicating with each other.
On October 11, 1680, La Reynie writes to Louvois, who wished to save Madame de Montespan while prosecuting the charges against the other persons, and proposed, with that end, to withdraw from the case the declarations made under torture by Filastre and the Abbé Cotton, which contained the gravest charges against the favourite: ‘It is certain, even if we found a legitimate expedient for concealing from the judges for the present the facts which it would be well to keep secret, even for the sake of justice itself, that these very facts would crop up again from the woman Chappelain, from Guibourg, Galet, Pelletier, Delaporte, and perhaps from several more when under trial.’
On the subject of the deposition made by Guibourg, La Reynie writes: ‘It is morally impossible that Guibourg has deceived us in his declaration, and that he invented what he tells about the incantations said in course of the masses on the women’s bodies. His mind is not active or consistent enough for such continuous thought as would have been necessary to invent what he had said on this subject, because, even supposing he were capable of such application, he has not enough acquaintance with what goes on in the world, and could not have devised so consistent a story in regard to Madame de Montespan.’ Elsewhere he writes: ‘Guibourg and the girl Monvoisin have corroborated one another about circumstances so particular and so horrible that it is difficult to conceive two persons being able to imagine and fabricate them unknown to each other. It seems that these things must have occurred, or they could not have been described.’
The illustrious magistrate adds the following reflections:—
‘1. The time of the relations of La Voisin with Latour, the journeys to Saint-Germain, and the powders which she made him work at, was the year 1676.
‘2. The time of the abominations described by Guibourg and the girl Monvoisin fits the same period.