DESCARTES (René). THE PRINCIPLES OF PHILOSOPHY. Paris, Michel Bobin and N. le Gras, 1668. In-4° of [56]-477-[2] pages, brown calf, spine ribbed and decorated (contemporary binding). Translation by Abbé Picot, a friend of Descartes, with a folded plate and numerous woodcuts in the text. The latter illustrate the important scientific treatises contained in this volume: the movement of the planets, elasticity, magnetism and atomistic chemistry. Binding worn with small tears, inside fresh.