Charles DARWIN (1809-1882). L.S., Down, Beckenham, Kent May 16, 1874, [to Gustave Dollfus]; 1page in-8 addressed to him; in English. To Gustave Dollfus (1850-1931), author of Principes de géologie transformiste. Application de la théorie de l'évolution à la géologie (Paris, F. Savy, 1874). Darwin thanks him for sending his Principles of Geology, "which I am sure I shall read with great interest; for it is a subject which I have long wished to see treated under your point of view"...