On September 20th, 1879 the British Medical Journal published a letter entitled “Gelsemium as a Poison” in which Doyle recounts his use of gelsemium as a treatment for neuralgia (nerve pain). Gelsemium is also called Yellow Jasmine (or Jessamine). This was not something which had been prescribed for him. This was before he had invented Sherlock Holmes, so it is curious that he gave Sherlock the same predilection for self-experimentation.
Doyle was “determined to ascertain how far one might go in taking the drug, and what the primary symptoms of an overdose might be.” Again, I remind you that this was not something which research to that point had suggested might work. He just wanted to try it and see how far it could go. Fortunately, Doyle was a good scientist and recorded his observations, dose and physiological effects. He avoided other drugs (eg: tobacco) while experimenting on himself, and dosed himself at the same time each day. What he did was effectively brew a tea from the flowers and take drops of it. In old-fashioned measurements each drop equals 1 “minum”. In modern measurements we’d call it 0.06 ml (so about 17 drops/minums = 1 ml).
The results were… (drum roll)…
At doses between 40 and 60 minums he observed no effects. This did not deter him, and he kept ramping up the dose. At least he started low and kept the increments small. Things got interesting at 90 minums (about 5.4 ml). About twenty minutes after ingestion Doyle experienced extreme “giddiness” and a form of mild paralysis. He was also experiencing a depressed mood. But this did not stop him. At 120 minums (7.2 ml) the giddiness was lessened, but several hours later he had vision problems to go with the mild paralysis, but still this did not stop him.
Increasing the dose to 150 minums (9 ml) actually helped reduce the vision, mental health and giddiness problems. But there were some other side effects which had been present in milder form a lower doses but were now practically unbearable: a headache and crippling, “prostrating”, diarrhea. But this did not stop him. (When I first read about this, it reminded me of the Very Hungry Catepillar. Why would you keep going when there were these side effects?)
Doyle increased the dose all the way to 200 minums (12 ml) but in addition to the headache and diarrhea his pulse grew so weak from the paralysis he knew he could go no further without risking his life. At last he stopped.
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 (of both the voluntary and involuntary motor systems). Doyle thought a person may become tolerant to its effects, much like they do to other drugs such as opium (his comparison, not mine). It is scary how close he came to overdosing (people have died from ingesting gelsemium) and therefore depriving the world of his later creation, Sherlock Holmes.
What I find most fascinating about this is how well Doyle stuck to the scientific method. It may seem odd that I am surprised by this given Doyle was a medical doctor, but he was also an ardent spiritualist. He believed in fairies, spirits and life after death, and even that mediums could communicate with the spirit world. These beliefs just seem at odds with the cold logic of his most famous character, Sherlock Holmes, and a rigorous scientific approach. Though famously modelled on Joseph Bell, I can’t help but wonder how much of Doyle as a young man (ie before his spiritual side became dominant) is in the character of Sherlock.
I stumbled across this story about Doyle while researching poisons for a story called Sever-Reign. That story wound up being highly commended in the 2017 Wordfest Competition and can be read for free here. It is also included in my anthology, Movemind. I have also self-experimented to improve my sleep which you can read about here. Next time I’ll talk about the accidental finding of millennia old texts and the controversy over what happened next.
This post is part of my Great Moments in Literature series. So you never miss a new Great Moment, please subscribe to my list or this website.