The Untamed Disease: New Perceptions and Medical Responses to Zhang (瘴) in the Lingnan Region during the Song Dynasty

This study examines how physicians and scholar-officials of the Song dynasty reconceptualized and medically confronted zhang -an uncontrolled and deadly tropical disease endemic to the Lingnan region of southern China. Since ancient times, the expansion of the Chinese cultural sphere toward the south had been shadowed by fears of the region's hot, humid climate and the "poisonous vapors" (duqi) believed to cause fatal illnesses. These environmental anxieties contributed to the cultural Othering of Lingnan as an uncivilized and perilous frontier, inhabited by "barbarian" peoples and veiled in superstition. While Sui and Tang physicians such as Chao Yuanfang and Sun Simiao distinguished zhang from cold damage (shanghan) and epidemic fevers (wenyi), their understanding remained theoretical and classificatory, relying on bianbing (disease categorization) rather than individualized bianzheng (pattern differentiation). In contrast, Song-period physicians-particularly the so-called ruyi (Confucian physicians)-advanced an empirical and practice-oriented medicine. Through direct observation and clinical experience, they transformed zhang from an untamed and supernatural affliction into a diagnosable and treatable syndrome grounded in empirical reasoning. This transformation unfolded within the broader socio-political context of the Song dynasty, when the empire's political and economic center shifted southward and the development of Lingnan became a national concern. The state's medical bureaus undertook extensive compilation projects, producing formularies such as the Taiping Huimin Heji Jufang and Shengji Zonglu Zuanyao, which aimed to standardize treatments throughout the empire. Yet these texts, rooted in northern medical paradigms, often failed to address the specific climatic and pathological conditions of the Lingnan tropics. In response, scholar-officials and local physicians-including Li Qiu, Zhang Zhiyuan, Wang Fei, Wang Nanyong, and Zhang Jie-compiled medical works such as the Lingnan Weisheng Fang. Drawing upon firsthand clinical encounters, they emphasized the importance of pulse examination, symptom differentiation, and ecological adaptation in treatment. Their efforts reflected a synthesis of classical medical theory and local medical knowledge, bridging state medicine and regional realities. Ultimately, this study argues that the transformation of zhang from a numinous affliction into a treatable disease signifies a critical epistemological shift in Chinese medical history. By confronting fear through observation, classification, and practice, Song physicians extended the boundaries of both medical rationality and civilization itself. The conquest of the "untamed disease" thus metaphorically represents the taming of the southern frontier and the integration of its environment into the moral and intellectual order of the empire.