Physicist. Son of a samurai of the Aizu clan. He went to study at the Sheffield Scientific School of Yale University in 1871. After serving as assistant professor at the Tokyo Kaisei School, he served as the first Japanese professor in the Faculty of Science of the University of Tokyo in 1879. By conducting double-check experiments on the occurrence of X-rays, etc, he supported the early days in the education of physics. He became the first Doctor of Science in Japan in 1888 and was elected a member of the Tokyo Imperial Academy in 1901. He assumed the presidency of the Imperial University of Tokyo the same year. He resigned from the post because of ways of coping with the Shichi Hakase Kenpaku Jiken(Seven Professors Petition Incident) in 1905. After serving as the president of the Imperial University of Kyushu, he again assumed the post of the president of the Imperial University of Tokyo in 1913. He concurrently served as the president of the Kyoto Imperial University for ten months from 1914 and was instrumental in educational administration. He was selected as a member of the House of Peers in 1905. He became privy Councillor in 1923.