After the peace of Rastatt (1714) he spent some time in travelling in Italy, Greece, the Levant, England and Germany, and devoted much attention to the study and collection of antiquities.

Chief among his antiquarian works must be the profusely illustrated Recueil d'antiquités égyptiennes, étrusques, grecques, romaines et gauloises (6 vols., Paris, 1752–1755),[2][a] which was mined by the designers of Neoclassical arts for the rest of the century.

[citation needed] His Numismata Aurea Imperatorum Romanorum, treats only the gold coinage of the Roman emperors, those worthy of collection by a grand seigneur.

He worked chiefly from drawings by Italian and French masters, including examples from the collection of Pierre Crozat and the Cabinet du Roi (the collection of the King); he also made many etchings from drawings by his friend Antoine Watteau and the sculptor Edmé Bouchardon.

His cultural interests were not confined to the arts of Classical Antiquity but extended to Gallic monuments, such as the megaliths of Aurille (Poitou), of which he commissioned drawings in 1762.

He had a thorough acquaintance with the gayest and most disreputable sides of Parisian life, and left a number of more or less witty stories dealing with it.