# Niter, pills of

**Pillole di nitro**

**Known today as.** Saltpeter, potassium nitrate.

Kind: Mineral  
Poisoning: Nitrate and the blue blood (https://thethinkingpress.org/materia-medica/poisons/nitrate)

## What did Canale use it for?

Among the pills commended for all complexions (ch. 4).

## What does modern science say?

Once given for many conditions, it survived in medicine chiefly as a diuretic. Potassium nitrate is a mild diuretic and was given for fevers into the nineteenth century; in grams it irritates the stomach and in larger amounts poisons the blood. The purging in the pill came from the aloes and scammony.

## Pharmacognosy and toxicology

- **potassium nitrate**: 
- **aloes and other purgatives**: in the pill mass

**Mechanism.** Nitrate is a mild diuretic and, reduced to nitrite by the mouth’s bacteria, a vasodilator that lowers blood pressure, the mechanism behind the modern beetroot-juice trials; in grams it irritates the stomach, and nitrite oxidises haemoglobin to methaemoglobin, the blue poisoning of infants from well water. The purging in the pill was the aloes.

**Dose.** A few grams of saltpetre give gastritis; 30 g has killed by methaemoglobinaemia and collapse.

**Standing.** Obsolete; nitrate’s cardiovascular action is under active study.

## What lore surrounds it?

The alchemists called saltpetre the dragon, since it devoured metals in aqua fortis, and the *sal petrae* was the salt that grew from the stone of damp walls; its explosive marriage with sulphur and charcoal was the other end of its history. See [Saltpetre](https://thethinkingpress.org/materia-medica/saltpetre).

## What did the older authorities say?

**The antidotaries.** Pills of niter, *pilulae de nitro*, were a purging pill of the Salernitan tradition: niter with aloes, scammony, and bitter seeds, for the head and the stomach, and for the stone, which niter was thought to dissolve.

**Pliny.** Gives *nitrum*, which for him is natron, for the stomach, the eyes, and the skin, and the medieval pharmacy carried his uses across to saltpetre when the names were confused.

## Sources

- Pliny, *Natural History* XXXI.
- *Antidotarium Nicolai*.
- Lundberg, J. O., et al. (2008). “The nitrate–nitrite–nitric oxide pathway in physiology and therapeutics.” *Nature Reviews Drug Discovery* 7.

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*Niter, pills of.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-01. The Thinking Press. https://thethinkingpress.org/materia-medica/niter-pills-of

Historical description, not medical advice.