Arthur Conan Doyle: Gelseminum as a Poison

Arthur Conan Doyle (1859-1930) studied medicine at the University of Edinburgh Medical School from 1876 to 1881. As part of his studies he, like so many others in that epoch, experimented with various potions on himself.

One such experiment even managed to get published in the austere Brititish Medical Journal. On September 20, 1879 the Journal published a letter entitled 'Gelseminum as a Poison' in which Doyle recounts his use of a tincture of gelseminum (now known as gelsemium) as a potential treatment of neuralgia, or neuropathic (nerve) pain[1].

The then 19-year-old Doyle was 'determined to ascertain how far one might go in taking the drug, and what the primary symptoms of an overdose might be'.

Doyle proceeded to prepare a tincture and recorded his observations like any good scientist should: he noted the dose and physiological effects, avoided tobacco, and dosed himself at the same time each day.

At low doses of 40 and 60 minums (2.4 to 3.6 milliliters) he observed no effects, but 20-minutes after ingesting 90 minums (5.4 milliliters) he experienced extreme 'giddiness'. At 120 minums (7.2 milliliters) the giddiness was abated, but several hours later he had vision problems. Any psychological symptoms were gone by 150 minums (9.0 milliliters), and all that remained were headaches and extreme diarrhea. Most would have stopped there, but not Doyle. He pushed on towards 200 minum (12.0 milliliters), at which the persistent and prostrating diarrhoea, a severe frontal headache, and a weak pulse forced him to abandon his experiments.

He concluded that healthy adults may take up to 90 minums, but that at doses of 90-120 the drug induces a sort of mild paralysis.

This letter 'Gelseminum as a Poison' was the first step in Arthur Conan Doyle's journey to become a famous writer.

The genus Gelsemium is contains three species of shrubs to straggling or twining climbers. Two species are native to North America, and one to China and Southeast Asia. All three species of this genus are poisonous. Reports of Gelsemium elegans poisoning are rare but not unheard of[2].

[1] Gibson, Green (Eds.): The Unknown Conan Doyle: Letters to the Press – 1986
[2] Zhou et al: Gelsemium elegans Poisoning: A Case with 8 Months of Follow-up and Review of the Literature in Frontiers of Neurology - 2017. See here.