Calomel

Traditional Use

Primary Actions

• Attacks toxins and kills parasites - used externally for scabies, ringworm, chronic sores, and other stubborn parasitic or fungal skin conditions.
• Relieves itching and dries Dampness - especially valued for intensely itchy, weeping, inflamed lesions where toxic Damp-Heat has lodged in the skin.
• Removes putridity and promotes tissue regeneration - incorporated into chronic-ulcer ointments when decayed tissue must be cleared so healthy flesh can regrow.
• Drastically purges retained water in rare internal use - historically used in tiny supervised doses for severe excess edema or ascites with bowel obstruction, but this is now largely of toxicological interest rather than routine practice.

Secondary Actions

• Modern use is overwhelmingly topical because the margin between classical efficacy and mercury toxicity is extremely narrow.
• Qing Fen must never be decocted - heat and inappropriate storage can change its chemistry and make an already dangerous substance even more hazardous.

Classic Formulas

• Sheng Ji Yu Hong Gao (生肌玉红膏) - famous wound-healing ointment in which Qing Fen helps remove putrid tissue and promote new flesh in chronic ulcers.
• Zhou Che Wan (舟车丸) - drastic hydragogue formula demonstrating the old internal use of Qing Fen for excess water accumulation and constipation.
• Shen Jie San (神解散) - topical antiparasitic powder traditions combining Qing Fen with sulfur and other external agents for severe itching and skin infestation.

Classical References

• Me & Qi identifies Qing Fen as mercurous chloride and emphasizes that its principal role is external use for parasites, itching, toxic sores, and putrid ulcers.
• The same source also preserves the historical internal use for severe edema while strongly framing it as toxic and tightly supervised.
• MINERAL TOXICITY NOTE: unlike less soluble mercury sulfide medicines such as cinnabar, Qing Fen is a more hazardous common mercurial and should be treated as a high-risk toxic mineral product.