# Silver

**Argentum*, *Luna**

**Known today as.** The white metal, given as leaf, in solution, and as lunar caustic, silver nitrate cast in sticks.

Kind: Mineral

> **Caution.** Taken by mouth over time it causes argyria.

## What was it used for?

Lunar caustic burned away warts and proud flesh; silver leaf gilded pills; and silver, as *Luna*, was the metal of the moon and the brain.

## What does modern science say?

Drops of silver nitrate in the eyes of newborns, introduced by Credé in 1881, prevented blindness from gonorrhoea. Colloidal silver taken by mouth does nothing useful and can turn the skin permanently blue-grey (argyria).

## Pharmacognosy and toxicology

- **silver nitrate**: lunar caustic
- **silver sulfadiazine**: the burn cream

**Mechanism.** Silver ions bind the thiols and the DNA of bacteria; in the body, swallowed silver is laid down in the skin as silver sulfide, blue-grey for life.

**Dose.** Argyria after grams of silver over months; colloidal silver sold as a cure-all has caused it.

**Standing.** Silver sulfadiazine is on the WHO list of essential medicines for burns; the FDA ruled colloidal silver products unsafe and ineffective in 1999.

## What did the older authorities say?

**The alchemists.** Called it Luna, the moon, second only to gold. See [Alchemy](https://thethinkingpress.org/inspirations/alchemy).

## Sources

- Credé, C. (1881). “Die Verhütung der Augenentzündung der Neugeborenen.” *Archiv für Gynäkologie* 17.
- Lansdown, A. B. G. (2006). “Silver in health care: antimicrobial effects and safety in use.” *Current Problems in Dermatology* 33.

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*Silver.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-09-30. The Thinking Press. https://thethinkingpress.org/materia-medica/silver

Historical description, not medical advice.