Charles Henry (1859–1926) was a Frenchlibrarian and editor. He was born at Bollwiller, Haut-Rhin, and was educated in Paris, where in 1881 he became assistant and afterward librarian in the Sorbonne. As a specialist in the history of mathematics, he was sent to Italy to seek some manuscripts of that nature which the government wished to publish. He edited several works upon kindred subjects, as well as memoirs, letters, and other volumes, and wrote critiques upon the musical theories of Rameau and Wronski. He is also credited with the invention of several ingenious devices and instruments used in psychophysiological laboratories. He published C. Huet's correspondence under the title Un érudit, homme du monde, homme d'église, homme de cour (1880), and he issued also Problèmes de géométrie pratique (1884) and Lettres inédites de Mlle. de Lespinasse à Condorcet et à D'Alembert (1887).