Editing Man in the Iron Mask (section)

====Affair of the Poisons====
{{main|Affair of the Poisons}}
In his 1932 book, Duvivier also linked Eustache Dauger de Cavoye to the [[Poison affair|Affair of the Poisons]], a notorious scandal of 1677–1682 in which people in high places were accused of being involved in black mass and poisonings. An investigation had been launched, but Louis XIV instigated a cover-up when it appeared that his mistress [[Françoise-Athénaïs, marquise de Montespan|Madame de Montespan]] was involved.{{sfn|Noone|1988|p=225}} The records show that, during the inquiry, the investigators were told about a surgeon named Auger, who had supplied poisons for a black mass that took place before March 1668. Duvivier became convinced that Dauger de Cavoye, disinherited and short of money, had become Auger, the supplier of poisons, and subsequently "Eustache Dauger".{{sfn|Noone|1988|pp=222–228}}

In a letter sent by Louvois to Saint-Mars on 10 July 1680, a few months after Fouquet's death in prison while "Eustache Dauger" was acting as his valet, the minister adds a note in his own handwriting, asking how it was possible that Dauger had made certain objects found in Fouquet's pockets—which Saint-Mars had mentioned in a previous correspondence, now lost—and "how he got the drugs necessary to do so".{{sfn|Mongrédien|1961|p=194}}{{sfn|Noone|1988|p=220}} Duvivier suggested that Dauger had poisoned Fouquet as part of a complex power struggle between Louvois and his rival [[Jean-Baptiste Colbert|Colbert]].{{sfn|Noone|1988|p=221}}