A Chinese Biographical Dictionary/Chang Chung
45Chang Chung 張中 (T. 景華). 14th cent. A.D. A native of Lin-ch'uan in Kiangsi, who was fond of study in his youth, yet failed to take his degree. He then left his books and began roaming over the mountains, where he fell in with a magician who taught him the black art; after which he became eccentric in manner and took to wearing an iron cap, thereby earning the sobriquet of 鐵冠子 the Iron-Cap Philosopher.