This isn’t a 17th century discovery, but “Dying to look good” is an interesting article on the recent discovery of gold in the bones of Henry II’s mistress, Diane de Poitiers. Liquid gold was believed to preserve youth, but it likely killed her.

It makes me wonder what Louis XIV’s mistresses resorted to. Certainly Athénaïs, the Marquise de Montespan, took witchy remedies of various kinds. 

It also makes me wonder what effect they might have had on her many children by the King.