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1. The custom in the Lingnan region is to consume Areca nut (Binglang, 槟榔); severe cases involve eating dozens of pieces daily. Generally, the onset of Zhang malaria (Zhang Nue, 瘴疟) is often due to overeating, leading to Qi stagnation and phlegm accumulation. Areca nut is particularly effective in descending Qi, promoting digestion, and resolving phlegm. Thus, people are accustomed to short-term benefits while ignoring long-term harms. This is somewhat similar to northerners consuming dairy products like butter and cheese, which often result in dense skin pores. Once an epidemic requires sweating therapy, the pores remain closed, preventing the release of pathogens. In the hot climate of southern China, the consumption of Areca nut causes the internal organs' Qi to become loose and diffusive. If one contracts a miasma disease requiring purgative or diaphoretic treatment, the body may be too weak and emaciated to tolerate it. Therefore, locals are often thin with sallow complexions. Is this solely due to climate? It is likely also a consequence of Areca nut consumption, though people fail to reflect on this.

2. The *Bencao* records that three men walked in the morning mist; only the one who drank alcohol remained healthy. Consequently, northerners crossing the mountains often encourage each other to drink wine. Exiled scholars and officials frequently get drunk to comfort themselves. Moreover, wine prices outside the mountains are particularly low, allowing laborers and vendors to drink freely, believing it wards off miasma. However, little is beneficial, but much breeds the source of miasma. Why? The southern land is hot and damp; excessive drinking leads to damp-toxin accumulation. Furthermore, Zhang malaria often arises from phlegm-fluid retention in the upper jiao, and wine tends to generate phlegm. A local proverb states: "Do not drink wine at Mao hour (5-7 AM), do not eat rice at Shen hour (3-5 PM)," which is indeed essential for health preservation. Thus, wine can both ward off miasma and save lives, or breed miasma and harm people. Life and death depend not on the wine itself, but on how humans use it.

3. In Guangnan, heat-toxin (Shu Du, 暑毒) is a frequent affliction. For more than half the year, the heat makes it difficult to avoid and easy to contract. Any slight lapse in diet or lifestyle can lead to heat-toxin invasion, especially when traveling on roads where exposure to heat is common. Locals warn each other against going out during summer. In remote areas with rugged roads and poor accommodation and food conditions, newcomers from the north often claim illness due to acclimatization issues. Upon return, this is called "Return Miasma" (Huitou Zhang, 回头瘴). It generally results from travel fatigue, exposure to heat, and improper diet and living habits.

4. The cold and heat patterns in Lingnan are irregular, making regulation difficult. Whether residing locally or traveling, winter and summer clothing must be available and adjusted promptly according to weather changes; delay can cause illness. Additionally, abnormal sea winds outside the mountains can easily cause disease if they penetrate the body. One should be cautious about changing clothes when sitting or lying down.

5. Although Lingnan is prone to heat diseases, cold damage (Shanghan, 伤寒) and epidemics occur in all seasons, varying in type. Locals label all illnesses as "miasma," leading to frequent misdiagnosis and mistreatment. In years with extreme cold resembling the Central Plains, locals, unaccustomed to sericulture and lacking silk cotton garments, live in drafty houses with insecure doors. Sudden cold spells can trigger epidemics the following year. Physicians treating epidemics should apply standard methods but adjust according to local climate, terrain, and patient constitution.

6. Zhang malaria often arises from latent summerheat combined with cold injury. Even without consuming cold foods, external cold invasion and internal dietary injury are usually involved. Cases with shallow latent summerheat and abundant cold are easier to treat; those with deep latent summerheat and abundant heat are harder to treat. Recently, northern physicians used Da Chaihu Tang (Major Bupleurum Decoction) to treat heat-type miasma. This requires patients with strong constitutions to tolerate it. Locals who have consumed Areca nut for long periods have weakened organ Qi and often cannot tolerate cold-natured medicines, let alone such potent formulas. Yet, locals see jaundice and deem it incurable, which is truly lamentable.

7. When northerners come to Lingnan, servants and maids often suffer from miasma qi. Laborers often have irregular diets, endure heat day and night, and sleep on the ground. Their inability to avoid hazards leads them to suffer first. Since we share their fortunes and misfortunes, we should take special care to warn them.

8. Common people summon shamans to sacrifice to ghosts and gods when ill. Scholars mock this superstition, preferring medicine. I find this pitiable rather than laughable. Though people may seem foolish, everyone seeks benefit and avoids harm, especially regarding life and death, which are obvious. If doctors could cure diseases, why would people not seek them? There are few good doctors in Lingnan, and medicinal herbs are scarce. People in valleys and islands have no access to medicine, so they turn to shamans out of necessity, not choice.

9. Miasma diseases vary, but locals consider "Mute Miasma" (Ya Zhang, 哑瘴) the most critical. Symptoms include immediate loss of voice upon onset, leading to death within one or two days. Physicians attribute this to extreme heat or internal heat triggered by external cold. Recently, northern physicians cured this using raw Aconite Root (Fuzi, 附子) decocted alone. Was this using heat to treat heat, or dispersing cold? I once heard of poisoning from stream water causing loss of voice. Thus, loss of voice is not always due to miasma. Stream water toxicity is real. With few wells on roads, riverside residents and hikers drink stream water. Accidental poisoning is possible. Perhaps this explains why travelers often suffer from this condition.

10. Legends say Lingnan has many poisonous plants; pigs eat them, and humans eating pig meat also get poisoned. Hence, northerners crossing the mountains are warned against eating pork. However, causes of miasma toxin in Lingnan are manifold, not limited to this. Shunquan stated: Pigs in markets eat beans and wine lees; those in villages eat bran, broken rice, and taro shoots, never grass. If true, then meat from cattle, horses, and sheep should also be avoided, which is absurd. This proves the legend unreliable.