(Berlin, Haude et Spener, 1766). 4to. No wrappers, as issued in ""Mémoires de l'Academie Royale des Sciences et Belles Lettres"", tome XX, pp. 91-164 (91-116"117-143"144-164). 1 engraved plate ( belonging to ""Microscope..."")
3 first editions by Euler in algebra, in optics and in the theory of chance - in this last paper he discusses the so-called St. Petersburg paradox, the Game Pharon.