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(Ancestors used the cicada insect, while modern people use the cicada slough; their qi properties are also similar.) Odor and flavor: Cold, Salty. Indications: Pediatric convulsions (Xiao'er Jingxian), nocturnal crying, epilepsy with alternating chills and fever.

Chen Xiuyuan stated: The Qi of the grasshopper cicada is cold, inheriting the Qi of Water; its flavor is salty, obtaining the taste of Water. However, it grows by absorbing the Qi of cool wind and clear dew, thereby acquiring the most complete Qi of Metal.

Its indication for pediatric convulsions is because Metal can pacify Wood (Liver). The grasshopper cicada sings when the sun rises and remains silent when the sun sets; thus, it stops nocturnal crying. Epilepsy with alternating chills and fever stems from Wind and Fire of the Liver and Gallbladder. The grasshopper cicada possesses the Qi of Metal and Water; Metal can restrain Wind, and Water can restrain Fire; therefore, it is used to treat these conditions.

Zhang Yin'an stated: Cicada slough (Chan Tui) and silkworm (Jiang Can) both inherit the essence of Metal and Water. Hence, the indications in the *Shennong Bencao Jing* are largely identical. However, the cicada drinks but does not eat, and urinates but does not defecate; the silkworm eats but does not drink, and defecates but does not urinate. Why are their effects similar? The Classic states: "Fluids enter the Stomach... and ascend to return to the Lung..." Grain enters the Stomach and is then transmitted to the Lung. Although dietary intake differs, all are governed by the diffusing and descending functions of Lung Qi. Thus, although urine and feces differ, they are all transformed and transmitted by inheriting Lung Qi.

Shigao (Gypsum Fibrosum) Odor and flavor: Acrid, Slightly Cold, non-toxic. Indications: Alternating chills and fever due to Wind-Stroke (Zhongfeng), rebellious Qi in the epigastrium causing palpitations and panting, dry mouth and scorched tongue, inability to breathe comfortably, hardness and pain in the abdomen, dispelling evil spirits (psychiatric disturbances), postpartum disorders, and metallic wounds (Jinchuang).

Chen Xiuyuan stated: Shigao has a slightly cold nature, inheriting the Cold-Water Qi of the Taiyang (Greater Yang) channel; its acrid flavor and non-toxicity obtain the Dry-Metal flavor of the Yangming (Bright Yang) channel. Wind is a Yang pathogen. When in the Taiyang channel, it manifests as aversion to cold and fever; however, one must verify the presence of anhidrosis, irritability, and panting before combining it with Mahuang Tang (Ephedra Decoction) or Guizhi Tang (Cinnamon Twig Decoction). When in the Yangming channel, it manifests as fever with slight aversion to cold; however, one must verify dry mouth, scorched tongue, intense thirst, and spontaneous sweating before combining it with Zhi Mu (Anemarrhenae Rhizoma). "Rebellious Qi in the epigastrium" is a synonymous expression for "rebellious Qi desiring to vomit" in the *Shanghan Lun*; "inability to breathe comfortably" is a synonymous expression for "emaciation and shortness of breath" in the *Shanghan Lun*. However, one must verify that this occurs after the resolution of exterior symptoms, where interior Qi is deficient and internal heat exists, allowing combination with Renshen (Ginseng Radix), Zhuye (Bambusae Folium), Banxia (Pinelliae Rhizoma), Maidong (Ophiopogonis Radix), Gancao (Glycyrrhizae Radix et Rhizoma), and Jingsmi (Oryzae Semen). Hardness and pain in the abdomen indicate excessive Dryness in Yangming leading to hardness, approaching the syndrome of gastric excess with constipation. "Evil spirits" refers to Yangming pathogenic excess causing delirious speech, hallucinations, or unprovoked fright, as if possessed by evil spirits; Shigao clears Yangming heat and can govern such cases. This addresses ulceration in the Yangming channel. However, mineral drugs become calcined gypsum (Duanshi) when exposed to fire. Modern practitioners, fearing its cold nature, often avoid using it, which greatly deviates from its original medicinal properties.