Philippe Villemot, a French doctor of theology, and a distinguished mathematician, published at Lyons in 1707 an astronomical treatise, entitled Nouveau Système, ou Nouvelle Explication du Mouvement des Planetes, in which, referring the movements of the planets to Cartesiab vortices, he announced the theory that their gravitation is occasioned by a difference of pressure, on their outer and inner faces, of the fluid constituting the solar vortex, owing to an increase of its density outward from the sun. The general conception is obviously somewhat similar to the speculation cursorily hazarded by Newton in 1679, and again recurred to by him (though only transiently) in 1717, or ten years later than the above publication by Villemot.
The details of this system cannot here be given, from want of access to his work. The Nouveau Système, however, appears to have been very favorably received by the author's contemporaries.