later called Le Sage's theory of gravitation, already in 1743. Then on 15 January 1747 Le Sage wrote to his father: Eureka, Eureka. Never have I had so much satisfaction as at this moment, when I have just explained rigorously, by the simple law of rectilinear motion, those of universal gravitation, which decreases in the same proportion as the squares of the distance increase. The first exposition of his theory, "Essai sur l'origine des forces mortes", was created by him in 1748, but was never published. In 1756 one of Le Sage's expositions of the theory was published, and in 1758 he sent a more detailed exposition of the theory to another competition of the Academy of Sciences. In this paper, entitled "Essai de Chymie Méchanique", he tried to explain both the nature of gravitation and chemical affinities. He shared the prize with one other entrant, but his theory of cohesion never gained acceptance, and only the gravitational portion of the theory was found to be of interest by a few of his contemporaries, including Euler. The exposition of the theory which became accessible to a broader public was "Lucrèce Newtonien" ("The Newtonian Lucretius"), in which the correspondence with Lucretius' concepts was fully developed. Another exposition of the theory was published from Le Sage's notes posthumously by Prévost in 1818, and was called "Physique Mécanique de George Louis Le Sage", but it does not contain anything which was not published in the earlier papers. Le Sage's predecessors Le Sage was not the first to propose what is now called "Le Sage's theory of gravity". Those who had described the theory previously include Fatio, Cramer, and Redeker. The extent to which Le Sage was influenced by these predecessors is a matter of controversy. Fatio The theory now called "Le Sage's theory of gravity" was originally proposed in the 1690s by Nicolas Fatio de Duillier, a friend of Sir Isaac Newton and Christiaan Huygens. Fatio was a well-known Swiss personage, and the kinetic theory of gravitation was his most notable scientific contribution, to which he devoted much of his life. Le Sage said that he heard of Fatio for the first time through his father, because his father had heard the prophecies of the cevénots (camisards), and told him that Fatio was among those prophets. Le Sage's father was well acquainted with the scientific fields in which Fatio worked, and he tutored