DESCARTES (René). LETTRES de Mr Descartes où sont traitées les plus belles questions de la Morale, Physique, Médecine et Mathématique. Paris, Henry le Gras, 1657. In-4° of [30]-663-[1] pages, brown calf, fillets on covers, spine ribbed and decorated (period binding). Genuine first edition as described by Tchemerzine, with several sketches in the text. This is one of the most important scientific correspondences and is of capital interest for the history of scientific and medical discoveries. Spine worn with small tears, hinges split, inside fresh. Old handwritten bookplate (Tchémerzine II, 785).