Ruskin's portrait of his Genevese friend Dr. Louis-André Gosse which he has drawn in Praeterita is, for all its tender charm, not without a touch of irony. By way of closing his acccount of the origin of Switzerland, Ruskin acknowledges his principal authority, La Suisse historique by the late professor Gaullieur of the University of Geneva, and recalls the time he had spent at Mornex in the chalet leased from M. Gaullieur's widow. Louis-Andre Gosse, the recipient of the letters by Ruskin, was the great-grandson of a French Protestant who, after the revocation of the Edict of Nantes, had emigrated to The Hague, and from there had opened bookshops in London and Geneva. Gosse probably diagnosed Ruskin's case correctly as a form of madness; this corroborates the theory underlying R. H. Wilenski's study of Ruskin, according to which 'Ruskin was always a manic-depressive invalid'.