Properties: Pungent, cold, toxic

Meridans Entered:
Primary: Heart, Liver and Kidney

1. Kills Parasites and counteracts Toxic Pathogens
   Sores and boils, scabies, malignant ulcers
   Gold, silver, copper, and tin toxicity
2. Aids fasting
   Mentioned in the Shen Nong Ben Cao Jing as part of the superior class of minerals which can, with protracted taking, make one an ever-living immortal. This may suggest it was part of supplementing the diet when engaging in an "avoiding grain" (Bigu 辟穀) fasting regime to cultivate life (Yangsheng 養生).

Suggested Daily Dosage: Applied externally.

Cautions: Traditionally contraindicated to pregnant women and internal consumption. Not recommended for any use today due to toxicity.

Notes:

The Chinese name for mercury it literally the same as the ancient Greek hydragyrum which derives from the words hydror - "water" + argyros - "silver".

This substance was of great importance in early alchemy where it was considered to be the True Yin in the centre of the trigram of Fire (☲ Li) representing cinnabar (Wong, 1997, Harmonising Yin and Yang: p 5-17).

This came from the observation that by placing cinnabar in the centre of a flame, the sulphur component separated and combusted leaving pure mercury, a heavy liquid (pure Yin) which must have seemed like a magical transformation to ancient alchemists.

Mercury also contains the unique property of amalgamating with other metals that it comes into contact with, which can then be separated out again with heat. This is especially important in gold mining where mercury can amalgamate with small pieces of gold which can then be separated out. This may be what is referred to in the Shen Nong Ben Cao Jing which states that "it kills the toxins of gold, silver, copper, and tin".

Although this became largely metaphorical in internal alchemy, a tradition of using cinnabar in medicinal pills has continued to this day (Liu et al, 2008).

However, even in ancient times, it was not without its critics. The Ming dynasty physician Li Shizhen wrote in 1578:

"the human body, which thrives on water and the cereals, is unable to sustain such heavy substances as gold and other minerals within the stomach and intestines for any length of time. How blind it is, in the pursuit of longevity, to lose one's life instead! ... However, while mercury is not to be taken orally, its use as a medicine must not be ignored."

Which suggests he still used mercury topically for sores and boils, as was common practice in Europe for syphilis from the fifteenth to early twentieth centuries.

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In western alchemy it was one of the primary substances that compromised all metals. There were two main theories of metals in medieval alchemy that both relied upon a "corpuscular" framework (that matter was made of small particles): the "mercury-sulphur theory" which considered metals to be composed of different proportions of mercury and sulphur, and the "mercury alone theory" which held that all metals are made of mercury and sulphur is primarily a pollutant.

Later, Paracelsus developed the theory of the Three Primes of Mercury, Sulphur and Salt in which the substances took on more abstract meanings. Mercury represented the omnipresent spirit of life, the volatile and mental aspect. As mercury was believed to transcend liquid and solid states, it was used to represent transcendence over other opposing states such as life/death and heaven/earth (Helmenstine, 2020, The Three Primes of Alchemy).

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Mercury is extracted from cinnabar or vermilion, mercury (II) sulfide, being the natural mineral ore cinnabar by heating in a flame or oven.

Its amalgamating property with gold made it an essential part of alchemy, both in its literal quest for making gold, and the symbolic quest for enlightenment.

Salt is one of the few substances which does not amalgamate or dissolve with mercury but remains completely separated. However, mercury can react with nitric acid (aqua fortis which can be derived from saltpetre, possibly the "salt" that is meant in the Three Primes) to form mercury nitrate. It can also react with alcohol to form mercury fulminate which is a primary explosive that was used in bullets and detonators (NileRed, 2017).

It does not react strongly with hydrochloric acid (HCl, Spirit of Salt / Muriatic acid) but can be converted to mercury (II) sulfate, HgSO₄, with hot sulphuric acid (H₂SO₄, Vitriol) which then reacts to hydrochloric acid to become mercury (II) Chloride, a highly toxic mercury salt known to alchemists as "corrosive sublimate" or "sulema".