Wu Collection, Middle Volume Radical: Sickness (bìng) 瘴 Kangxi strokes: 16 Page 779, Entry 23 Guangyun (Guangyun), Jiyun (Jiyun), and Yunhui (Yunhui) define it as zhi liang qie, pronounced zhang. Yupian (Yupian): Zhang is a pestilence. Guangyun (Guangyun): A fever. Zhengzitong (Zhengzitong): The poisonous vapors (li qi) from mountains and rivers that cause illness. Lu You's Bieshu manchao (Bieshu manchao): In the southern mountain ranges, one may sometimes see a strange object falling from the sky. At first, it is the size of a pellet, then gradually it grows to the size of a carriage wheel, and finally, it scatters. If a person is struck by it, they immediately fall ill; this is called the mother of vapors (zhang mu).