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Camphor (Borneolum Syntheticum) receives the pure Yang Qi. Its taste is pungent, and its nature is hot. Initially decocted in water, it burns fiercely when exposed to fire, suggesting it possesses the nature of "Dragon Fire" (a metaphor for intense, erratic heat). Its aroma is penetrating, capable of unblocking orifices and expelling malignant evil Qi. It can also dispel dampness and kill parasites; burning its smoke to fumigate clothes and mats repels bedbugs and moths. Applied as powder to the soles of the feet, it treats cold-damp Hong Kong foot (tinea pedis). For all types of scabies, tinea, pustular sores, wind-scratching, and damp-toxins, it is an essential external medicine for sores and ulcers.

Hibiscus mutabilis (Mufurong), receiving the Qi of late summer and early autumn, has a pungent taste. Pungency belongs to Metal transformation, thus it can clear the Lungs. Its nature is neutral, which implies coolness, so it can cool blood, dissipate heat, and resolve toxins. It specifically treats all kinds of carbuncles, sores, swelling, toxic sores, promotes pus discharge, and relieves pain. The flowers, dried in the shade, treat infant malnutrition (Gan accumulation) with miraculous effect. For all carbuncles and sores, collect Hibiscus leaves before the Double Ninth Festival, dry them in the shade, and grind into powder. Collect Xanthium sibiricum (Canger) before the Dragon Boat Festival, burn until charred but retaining essence (burnt to preserve nature), and grind into powder in equal parts. Mix with honey water and apply around the lesion to prevent toxin spread. This is called "Iron Well Fence Powder" (Tie Jing Lan San), which is excellent.

Nicotiana tabacum (Yancao), best produced in Fujian, is pungent, warm, and slightly toxic. It treats wind-cold-damp bi syndrome, moves stagnant Qi and retained phlegm, dispels mountain miasma and pestilential vapors, and washes away pus-sores and scabies mites. People use it as a substitute for wine and tea, never tiring of it; if they tire of it, illness arises. Addiction cures illness; it can sober the drunk and intoxicate the sober. Its Qi enters the mouth and circulates through the whole body instantly, making the entire body feel comfortable, seemingly unifying Blood and Qi and promoting Ying and Wei (nutritive and defensive Qi) (hence another name: Love Grass). However, the fire's scorching nature consumes Blood and damages Spirit. Thus, while it benefits from warding off cold and dissipating heat, it is contraindicated for fire syndromes and Yin deficiency.

Cinnamomi Cortex (Rougui) receives Heaven and Earth's Yang, combined with Earth and Metal Qi. Therefore, its taste is sweet and pungent, its nature is greatly hot, and it has slight toxicity. It is the wood-type herb that tonifies Yang. The one with thin Qi is Cinnamomi Ramulus (Guizhi); thin Qi leads to dispersal, so Guizhi ascends to release the exterior. The one with dense Qi is Rougui; dense Qi generates heat, so Rougui descends to tonify the Kidney. This follows the principle of Earth adhering to above and below. Sweet, pungent, and greatly hot, it benefits Yang. Sweet enters the Blood aspect, pungent moves horizontally, and heat promotes circulation, thus it nourishes blood vessels, tonifies the Gate of Vitality (Mingmen), and regulates heart and abdominal disorders. It treats cold-induced cholera with muscle cramps, tonifies deficiency of Qi pulses, fatigue and internal injury insufficiency, warms waist and knees, strengthens sinews and bones, breaks stasis and relieves pain, dispels wind-bi and joint pulling pain, deep-seated chronic cold in the abdomen, expels wind-cold from Ying and Wei, and treats nine types of heart pain. It unblocks amenorrhea and menstrual stasis causing pain, induces difficult labor and expels the afterbirth. Contraindicated in excess Yang and deficient Yin. Choose those rolled like tubes, with purple-moist flesh, extremely sweet yet pungent taste. Before use, remove bark and break pieces; otherwise, Qi and flavor are lost, and efficacy diminishes. Avoid roasting over fire, as aromatic herbs lose efficacy when heated. Produced near Ziguanbin, hence named Official Cinnamon (Guangui). Named Gui Xin (Heart of Cinnamon) is a term of praise, referring to the innermost, very purple and very sweet part after removing all coarse bark. If used in tonifying formulas to encourage drug properties, decoct together with other herbs. If relying entirely on its blood-moving and penetrating action, add it to the decoction of other herbs for only one or two boils.

Rougui can induce abortion and unblock blood vessels. For lower jiao cold, autumn/winter abdominal pain, running piglet syndrome (Ben Tun), it promotes urination, warms meridians and organs, breaks blood stasis and unblocks menstruation, saves primordial Yang from chronic cold, supports Spleen and Stomach deficiency-cold, strengthens sinews and bones, boosts Yang channels, warms and moves all drugs. Essential for lumbar and hypochondriac pain, harmonizes blood and expels stasis-pain, eliminates wind-qi and sores swiftly, promotes Qi and Blood without stagnation, benefits joints with agility, supports carbuncles and smallpox toxins, guides Blood to form pus. Pungent disperses wind, sweet harmonizes blood, warm moves Qi, aromatic penetrates hundred vessels. Regarding its use, there is the meaning of "wood withers when meeting cinnamon." Dense Qi generates heat, enters Liver and moves to Kidney, specifically tonifies deficiency of true Fire in Mingmen, and guides fire back to its source. Hence, "Gui" sounds like "Gui" (jade tablet), guiding Yang Qi as if commanding with a jade tablet. Used at childbirth to induce labor, delivering quickly as if pushed by hand, is also due to the power of tonifying fire, entering Liver and moving to Kidney. Contraindicated in Spring/Summer, suitable for decoction in Autumn/Winter—this is the constant rule. Deviating from season to follow symptoms is the variable rule. For malaria with persistent chills and fever, take high-quality scraped Rougui, remove all coarse bark, about one qian weight. Hold in mouth just before malaria onset; chills recede, fever reduces, spirit refreshes, appetite returns, and cure is visible, demonstrating its divine merit of tonifying true fire and dispersing yin cold. Guizhi has thin Qi and light body, ascends to head and eyes, moves horizontally to arms, harmonizes Ying and Wei and muscle surface, stops vexation and sweating, disperses pathogenic wind, internally regulates heart and abdominal pain, externally resolves skin cold. It acts directly as a guide for Ben Tun, as the meridian runs through Bladder. It stops sweating when present, induces sweating when absent, because it harmonizes Ying and Wei, preventing pathogen retention and regulating opening/closing. Mahuang and Guizhi are both pungent-sweet and dispersing. However, Mahuang penetrates skin and hair thoroughly, specializing in inducing sweat to scatter cold pathogens. Guizhi harmonizes Ying and Wei, excels in resolving muscle layer to scatter wind pathogens. This is what is meant by "thin Qi leads to dispersal."

Main Indications (Integrating Smallpox): Harmonizes Ying and Wei, surrounds muscle surface, repels wind pathogens and solidifies couli (pores). For Qi-deficient smallpox, it relies on its encouraging action. Drug nature ascends, unifies hundred vessels, guides Ginseng to reach muscle surface, supports smallpox toxins and carbuncles, guides Blood to form pus, controls Liver and tonifies Spleen, harmonizes Qi and Blood. Contraindicated for diarrhea with chills, white/pale deficient-cold smallpox, real-heat smallpox syndromes, and sores appearing after smallpox.

Guizhi has thin Qi, ascends and releases, and can move horizontally to arms. Suitable for initial heavy exposure to wind-cold, during autumn/winter, and for hand/foot sores that fail to erupt. Contraindicated for excessive phlegm with cough, sore throat with hoarseness, blood dryness, blood heat, metrorrhagia, and pregnant women.

Commentary by Zhang: Cinnamon (Gui) and Aconite (Fu), although both pungent-hot and tonifying Yang, ancient masters formulated prescriptions with both, with Gui alone, or Fu alone. There should be fixed principles, precise matching, and no mutual substitution or mixing. Modern people do not investigate their subtleties, merely using either Gui or Fu arbitrarily due to their pungent-warm nature. They do not know that Rougui is sweet and pungent, aromatic and penetrating, capable of ascending/descending, horizontal/vertical, exterior/interior, tonifying/draining, good at unifying hundred vessels and smoothing meridians, encouraging Qi and Blood. Although its moving effect is swift, its nature specializes in draining, and its power to warm middle and save interior is hard to sustain, leading to rapid advance and retreat. As for Fuzi, its taste is greatly pungent, slightly sweet-bitter, dense Qi but thin taste, descending more than ascending, straight up from below, moving without staying. Its strengths are saving interior, restoring Yang, guiding fire to store source, warming meridians and reaching collaterals. This differs from Rougui's pungent-sweet, light-yang nature, which can move horizontally to exterior and penetrate hundred vessels. One is pungent with slight bitter, so its function specializes in reaching down, moving interior to save Yang within Yin, being the medicine for primordial True Yin and True Yang. The other is sweet with pungent, so it both tonifies Mingmen and can penetrate up to exterior to save Yang extinction, being more needed for post-natal Qi, Blood, Ying, and Wei. Therefore, for purely large-warm severe tonification of Middle Qi, True Yin/Yang, focusing on saving interior, either combine both, or make Shen and Zhu the sovereign, with Fu as assistant, such as Ba Wei Wan requiring both Gui and Fu, Shen Fu Tang, Zhu Fu Tang, Li Zhong Tang, etc., do not use Rougui. If desiring to warm middle while harmonizing Qi/Blood, moving outward to exterior, focusing on exterior, make Qi/Blood tonifying herbs as sovereign, and use Rougui alone as assistant/envoy, such as Shen Yin, Shi Quan Da Bu Tang, Ren Shen Yang Rong Tang, etc., do not use Fuzi. In this way, the meanings of exterior/interior, Yin/Yang, and light/heavy are clear, how could one allow mixing and borrowing!