Léon Walras
In the early 1870s, William Stanley Jevons, Carl Menger, and Léon Walras each reintroduced the theory of marginal utility. During discussions of which of those three had been the first to formulate the theory, a colleague of Jevons discovered a copy of Die Entwicklung. However, the discovery (in 1878) came several years after the three principals in the Marginal Revolution had published their own books, and significant differences with Gossen’s original contributions were overlooked.