Leonhardi Euleri Opera Omnia IVA/7: Commercium Epistolicum (Euler – French Speaking Scientists from Switzerland). Editors: S. Bodenmann, V. Hug, M. Ilić, A. Kleinert. Basel: Birkhäuser, 2017, XII+621 pages – A volume overview

We give an overview of the seventh volume of series IVA of the Birkhäuser edition of Leonhard Euler’s complete works and correspondence. This volume contains Euler’s correspondence in French with ten of his Swiss countrymen: Louis Bertrand, Charles Bonnet, Marc-Michel Bousquet, Jean de Castillon, Gabriel Cramer, Philibert Cramer, Gaspard Cuentz, Albrecht von Haller, Georges-Louis Lesage and Johan Caspar Wettstein. A letter of the German Johann Michael von Loën to Euler, mentioned in the Euler-Bertrand letter exchange is also included as well as the recently rediscovered first letter of Euler to Jean le Rond d’Alembert in supplement. The letters cover a large range of topics also outside Euler’s mathematical and physical interests giving a new insight into his non-scientific activities, and thus casting also a new light on this great scientist as a person.