Library

The *Shuowen Jiezi* explains the character "Yi" (Epidemic), meaning that all people are sick. The structure involves the radical "Disease" (illness), with a phonetic component derived from "Yi" (service/役) in abbreviated form. The lost chapters of *Suwen* in the *Neijing* discuss the Si Tian and Zai Quan energies, where irregular ascending and descending movements, sudden stagnation of the Five Movements (Wu Yun), and loss of balance between rigid and soft forces lead to the transformation into epidemics after three years. Therefore, it is said that when the five plagues arrive, they are all contagious, regardless of age, with similar symptoms. This corresponds to what Zhang Zhongjing described as: "In one year, the illnesses of both young and old are often similar." By the Song and Yuan dynasties, this was no longer called "Yi" but "Wen" (Plague).

The modern sage Yu Jiayan stated: The abnormal qi of the four seasons harms humans and causes disease; initially, it is not called an epidemic. It becomes an epidemic only when patients die, and the pathogenic qi mixes with corpse qi. Thus, chicken plague kills chickens, swine plague kills pigs, and cattle/horse plague kills cattle and horses. Applying this to humans, why would it be different? For example, the so-called "Big Head Plague" refers to swelling of the head, face, cheeks, and jaw, resembling a gourd. The "Twisted Neck Plague" refers to throat obstruction with loss of voice, swollen neck, and distended abdomen, resembling a toad. The "Melon Rind Plague" refers to high chest and rising flanks, vomiting fluid like blood. The "Yangmei Plague" refers to purple patches all over the body, suddenly appearing like syphilitic sores. The "Lump Plague" refers to lumps emerging like tumors, moving throughout the body, causing death from morning to evening. The "Intestine Twisting Plague" refers to borborygmus, dry retching, and inability to pass water or stool. Childhood diseases such as sand pox and smallpox are also highly contagious. Additionally, Liu Songfeng mentioned various names such as Grape Plague and Cormorant Plague, which do not warrant deep investigation. Chen Suzhong stated that fierce and violent major illnesses result in death within a few days. Dai Tianzhang said that if the plague affects humans, humans get sick; if it affects objects, objects are harmed. Zhang Shiwang claimed that the pathogen of seasonal epidemics arises from the stagnation and steaming of damp earth, akin to the toxicity of fog and haze, originating either from mountains, plains, and lands, or from rivers, wells, and ditches. Yang Lishan stated that the arrival of toxic fog has no cause, and the emergence of smoke and miasma has no fixed time. Any abnormal qi of pestilence, drought, or flood often affects birds, beasts, grass, and trees, occurring once every few years or once every few decades. If one does not understand the syndromes and treatments, attributing everything to fate is truly lamentable.

Predecessors' discussions on epidemics were extremely precise and detailed. Today's people only hear of Western theories regarding the Black Death and new theories on bubonic plague, as if Chinese medicine practitioners know nothing about epidemics. In fact, Chinese medicine does discuss epidemics. Chinese medicine distinguishes between Big Head Plague, Twisted Neck Plague, etc., describing conditions such as swollen and hard lymph nodes in the cheeks and jaw, throat obstruction with loss of voice, and vomiting blood-like fluid, which closely resemble the manifestations of bubonic plague. Recently, Chinese physicians studying Western theories have published specialized books on bubonic plague, mutually illuminating each other. Among types of bubonic plague, there is another named Pneumonic Plague. "Yan" means heat; thus, Pneumonic Plague refers to lung heat. Ye Tianshi (Xiangyan) stated: Warm pathogens enter from above and first attack the Lung. Symptoms include fever, cough, and in severe cases, panting, confusion, macules, rashes, hematemesis, or epistaxis. These align with lung heat syndromes and are termed Wind-Warmth, commonly known as Winter-Warmth or Spring-Onset. Being unfamiliar with Eastern and Western theories and lacking clarity, I speak only within the boundaries of Chinese medicine; whether this is erroneous or not, I cannot say.

"Wen" and "Wen" sound the same but differ in meaning; "Wen" (Plague) is equivalent to "Yi". Lu Jiuzhi discussed this in detail. Yu Shi also stated that in midsummer, Damp-Warmth syndromes contain hidden epidemic pathogens; if one person contracts it, it is Damp-Warmth; if a region contracts it, it is an epidemic. Cold Damage and Warm-Heat diseases arise from the normal pathogens of the four seasons, whereas epidemics arise from abnormal pestilential qi of heaven and earth. The pathogens of Cold Damage and Warm-Heat enter from the exterior, while epidemic pathogens enter through the mouth, nose, and membrane source, proceeding directly along the central pathway and spreading through the Triple Burner. This discussion is most concise, and treatment methods are detailed in this book. However, warm, hot, damp, and cold qi can all become epidemics. Wu Keyou's *Treatise on Warm Epidemics* advocates Da Yuan Yin for treating Damp Epidemics. Yu Shiyu's *Treatise on Epidemics* advocates Qing Wen Bai Du Yin for treating Heat Epidemics. Su Dongpo's Sheng San Zi treats Cold Epidemics. Commonly used formulas today include Pu Ji Xiao Du Yin, Yu Shu Dan, Zi Xue Dan, Gan Lu Xiao Du Dan, Lian Xiong Dan, and Shen Xi Dan; both ancient and modern formulas can be utilized. Yu Shiyu's *Differentiation of Epidemic Syndromes* is precise and detailed; Wang Mengying's *Latitude and Longitude of Warm-Heat* is particularly valuable. Gan Lu Xiao Du Dan treats epidemic pathogens of summer-heat, dampness, and heat still in the Qi level; Shen Xi Dan treats warm-heat entering the Ying level directly; Qing Wen Bai Du Yin is a formula for draining fire from the twelve meridians.

I still remember that in the 28th year of Guangxu (1902, Ren Yin year), a major epidemic broke out in Shanghai. My teacher reasoned that Shaoyang governed the Heaven Qi, and the movement corresponded to Wind-Wood. With wind and fire stirring together, he combined acrid-cool and heavy-settling agents, using San Shi Tang as the main formula, achieving significant efficacy. Students at the time applied this method and observed miraculous results. Unfortunately, these case records were lost and could not be collected. In the 7th year of the Republic of China (1918), I intended to collate and print the copied cases. However, panic over the bubonic plague in Nanjing was particularly intense. Since previous texts had been published in daily newspapers for social reference, and due to my classmate He Yongqing recounting matters from my teacher's school, lamenting the absence of epidemic cases, I drafted this text to supplement them. I inevitably invite criticism for adding inferior appendages to a fine work. (Wen Hanzhi)