Louis Bertrand Castel, French mathematician and philosopher (d. 1757)
Louis Bertrand Castel (5 November 1688 – 11 January 1757) was a French mathematician born in Montpellier, who entered the order of the Jesuits in 1703. Having studied literature, he afterwards devoted himself entirely to mathematics and natural philosophy. After moving from Toulouse to Paris in 1720, at the behest of Bernard de Fontenelle, Castel acted as the science editor of the Jesuit Journal de Trévoux.He wrote several scientific works, that which attracted most attention at the time being his Optique des couleurs (1740), or treatise on the melody of colours. He also wrote Traité de physique sur la pesanteur universelle des corps (1724), Mathématique universelle (1728), and a critical account of the system of Sir Isaac Newton in 1743.