Strychnine

Strychnine is a notorious poison, obtained from fruits of the strychnine tree. It kills by disrupting the muscle contraction pattern required for breathing. Plant experts Josh Nolan, Rachel Webster and Liz Sheffield explain how this toxin works, and why, despite a ban on its use as a pesticide, people are still dying after ingesting it

Photograph of Materia Medica samples of Strychnos nux-vomica seeds from the Manchester Museum Herbarium’s collection. The seeds are stored in labelled jars and boxes, as they would have been by Victorian chemists

Strychnos nux-vomica — the ‘poison nut tree’ — is a plant with an interesting history. Tribal natives of South America traditionally use extracts of this and related species on the tips of their hunting arrows. Yet strychnine also has a long-standing and well-documented use as a medicine. Victorian pharmacists kept the seeds as part of their stock medicine cabinet and it was easy to obtain over the counter. Jars and boxes of these specimens can still be found in museums.

Breathing