# Sorrel, syrup of

**Siroppo acetoso**

**Known today as.** Probably the *syrupus acetosus* of the pharmacopoeias, syrup of vinegar, which the London Dispensatory gives to prepare the stomach for a vomit; the name could also mean a syrup of sorrel, *Rumex acetosa*, which the College made like the other sour syrups.

Kind: Compound  
Poisoning: Oxalate poisoning (https://thethinkingpress.org/materia-medica/poisons/oxalate)

## What did Canale use it for?

In the mildest vomit, with barley water (ch. 5).

## What does modern science say?

Sorrel is sour from its oxalate; eaten freely, the leaves have caused poisoning by their potassium binoxalate. Oxalate binds calcium and other minerals and can crystallise as calcium oxalate in the kidney; in 1989 a sorrel soup with 6–8 g of oxalic acid killed a 53-year-old man who had other conditions.

## Pharmacognosy and toxicology

- **oxalic acid**: 
- **potassium hydrogen oxalate**: 

**Mechanism.** Oxalate binds calcium; carried to the kidney it can crystallise there as calcium oxalate and block the tubules.

**Dose.** A lethal adult dose of oxalic acid is estimated at 10–15 g, and 4–5 g was thought the least able to kill; the fatal sorrel soup held 6–8 g.

**Standing.** A food in moderation.

## What lore surrounds it?

Culpeper says the syrup of vinegar, taken as half an ounce at bedtime the night before, makes one “vomit the easier,” which is the part the acid syrup plays in Canale’s gentlest vomit with barley water.

## What did the older authorities say?

**Dioscorides.** Gives *lapathon*, the docks and sorrel: the herbs boiled soothe the intestines, and the seed, in water or wine, serves for dysentery, a nauseous stomach, and the strike of a scorpion.

**The cooling syrups.** The London Dispensatory makes syrup of sorrel like the syrup of citron juice, among the sour syrups that “cool and comfort the heart”; the syrups of vinegar cool the body and quench thirst, and the citron syrup Culpeper gives in fevers, pestilential and not.

## Sources

- Dioscorides, *De materia medica* II.
- Culpeper, N. (1653). *Pharmacopœia Londinensis*.
- Felter, H. W., & Lloyd, J. U. (1898). *King’s American Dispensatory*, “Rumex Acetosa.—Sorrel.” As transcribed at Henriette’s Herbal Homepage.
- Salgado, N., et al. (2023). Oxalate in foods: extraction conditions, analytical methods, occurrence, and health implications. *Foods* 12: 3201.

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*Sorrel, syrup of.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-03. The Thinking Press. https://thethinkingpress.org/materia-medica/sorrel-syrup-of

Historical description, not medical advice.