In his testament to his daughter, Condorcet tells us that his wife, Sophie de Grouchy, as well as her Lettres sur la Sympathie, wrote other texts in moral philosophy.
These are apparently lost, along with her manuscript of the Lettres.
In the summer 2015 I visited the Bibliotheque de l'Institut in Paris, on the Quai de la Monnaie, where Condorcet and Grouchy used to live, and which houses all the papers related to the Academie Francaise. I was hoping to find some trace of her papers.
I found her will, stating that she left her papers to her daughter, Eliza, and her sister, Charlotte Cabanis. Her executor was Madame de Lasteyrie, Lafayette's daughter.
Next stop the Cabanis archives?