French physician; born in Durmenach, Upper Rhine, May 30, 1845; died in Paris May 4, 1902; son of the chief rabbi of Colmar. After completing his studies at the college of Colmar,Klein went to Paris, where he engaged in the study of medicine. While still a student he together with Emil Javal translated into French Helmholtz's "Handbuch der Physiologischen Optik." In 1873 he took his degree of M.D., his thesis being "L'Influence de l'Eclairage sur l'Acuité Visuelle," which was awarded a prize by the medical faculty of Paris. In 1871 he published "La Thérapeutique de l'Œil au Moyen de la Lumière Colorée," a French translation of the German work by Boehm. He contributed to "L'Opinion Nationale," editing its scientific page from 1872 to 1876, and also to the "Revue des Sciences Médicales" and other medical journals. He further wrote: "Le Diabète Sucré," 1876; "Le Psautier du Dr. Graetz," 1877; "La Circoncision," 1888; Sur l'Origine de Quelques Idées des Délirantes dans la Paralysie Générale," 1888; "Polémiques Nombreuses dans l'Univers Israélite." The minister of the interior decorated him in 1900 with the Golden Medal for his long and disinterested services in behalf of the poor.
Klein was a member of the Jewish Consistory of Paris, and during eighteen years president of the Société de l'Etude Talmudique. He was the representative, both within and without the consistory, of ultra-Orthodoxy; and as he was a profound Talmudist, his views carried great weight in the deliberations of the various societies of the Jewish community in the French capital.
- A la Mémoire du Dr. N. Th. Klein, Membre du Consistoire Israélite de Paris, published by the Société de l'Etude Talmudique, Paris, 1902.