By Anne Garner, Curator, Center for the History of Medicine and Public Health

“Upon my word, Watson!” said Holmes at last with an unsteady voice, “I owe you both my thanks and an apology. It was an unjustifiable experiment even for one’s self…A candid observer would certainly declare that we were [mad] before we embarked upon so wild an experiment. I confess that I never imagined that the effect could be so sudden and so severe.”

                                                –Arthur Conan Doyle, “The Adventure of the Devil’s Foot” (1910)¹

Illustration by Gilbert Holiday from the 1910 publication of “The Adventure of the Devil’s Foot” in The Strand magazine.

Nineteenth- and twentieth-century botanical dictionaries lack any mention of radix pedis diaboli. Curious readers will need to turn instead to fiction to find it, and to the Sherlock Holmes stories of Sir Arthur Conan Doyle. Conan Doyle’s short story, “The Adventure of the Devil’s Foot,” was published in 1910, and pivots on this fictional poisonous plant.

In the story, the plant—devil’s foot root—is little-known even in West Africa, its point of origin. Its transport to England is the work of the story’s lion-hunting physician, Dr. Leon Sternsdale.

The case involves the mysterious injuries sustained by four siblings (two are fatal). En route to the story’s solve, Holmes detects a strange brown powder on the smoke-guard of a lamp at the scene. Soon after, he proposes that he and Watson undertake a medical experiment to determine the powder’s effects on the body. The always accommodating Watson assents. Holmes then lights the lamp, burning the powder with the window and door ajar for ventilation.

The impact is immediate: Watson describes a “turmoil in his brains” and a mounting loss of control of both mind and body. At the last minute, Watson marshals his reason and tackles Holmes, pushing him out of the room, where the pair of them lie breathless on the grass outside as the fumes and the poison recede. Holmes’ suspicions are confirmed: the powder is toxic, and he’s able to link the deaths to the devil’s foot root, with the help of Sternsdale.

As a third-year medical student at the University of Edinburgh, Doyle embarked on his own experiment with a toxic root. Gelsemium (sometimes gelseminum), a dried rhizome of yellow jasmine, was rumored to have been discovered by a Mississippi planter who accidentally made a tea for his master using the root, and cured him of his fever (though with side effect—loss of muscle control).²

Doctor Conan Doyle in academic regalia for his graduation in August 1881. In Rodin and Key, Medical Casebook of Doctor Arthur Conan Doyle: From Practitioner to Sherlock Holmes and Beyond, 1984.

By the mid-19^th century, gelsemium had gained a reputation with a handful of medical practitioners in the Midwest as a remedy for pneumonia, pleurisy, and other ailments. In 1879, Doyle, who had been taking a tincture of gelsemium for some time to combat neuralgia, began to experiment with it, incrementally increasing his dosage.³

Doyle published his findings in a letter to the editor in the September 20, 1879 issue of the British Medical Journal, under his initials, A.C.D. Doyle writes that he was “determined to ascertain how far one might go in taking the drug, and what the primary symptoms of an overdose might be.” He concludes that gelsemium, like opium, could be tolerated with increased exposure, though at 200 minims Doyle ceased his experiments because of debilitating stomach issues.⁴

Gelsemium. In Millspaugh, American Medicinal Plants, 1887.

Holmes and Watson’s symptoms in the “Adventure of the Devil’s Foot” in some ways conjure the effects of the gelsemium described by Doyle in the BMJ. Watson reports a “freezing” loss of muscular control and partial paralysis as well as loss of the senses. Doyle recounted similar symptoms after ingesting gelsemium. At the highest dosages, Doyle reported severe depression. Watson, too, describes feelings of dread:

“A thick, black cloud swirled before my eyes, and my mind told me that in this cloud, unseen as yet, but about to spring out upon my appalled senses, lurked all that was vaguely horrible, all that was monstrous and inconceivably wicked in the universe.”⁵

Self-experimentation was common during Conan Doyle’s lifetime. And yet, it’s somewhat surprising that Conan Doyle endeavored to take on this project. As historians Rodin and Key note, Conan Doyle writes in his autobiography, “I had…no great interest in the more recent developments of my own profession, and a very strong belief that much of the so-called progress was illusory.”⁶ Why then, was Conan Doyle so determined to ascertain the limits of the drug, particularly when he knew of life-ending overdoses? (At peak dosage, Doyle took 2 1/2 times the fatal amount.)

Arthur Conan Doyle. In his Memories and Adventures, 1930.

The answer is not clear, but may suggest an early fascination with poisons, which decorate so many of Conan Doyle’s Holmes and Watson stories. As a medical student at the University of Edinburgh, Conan Doyle studied with several eminent toxicologists, including Sir Robert Christison and Sir Thomas Richard Fraser.⁷ Conan Doyle’s service as ship surgeon on a voyage to West Africa may also have familiarized him with poisons that inspired the “devil’s foot root” of the Holmes story.

Rodin and Key suggest that not only was Conan Doyle interested in poisons, but he was also a risk-taker. They write that the experiment was a “reflection of the bravado, the sense of the dramatic, and the spirit of adventure already noted in many of his endeavors—experiences as a ship’s surgeon and involvements in war and sports.”⁸ Conan Doyle bestowed these qualities on his crackerjack gumshoe. In “Devil’s Foot,” Holmes admits that testing the poison is somewhat reckless—and yet we can’t imagine him behaving otherwise.

Southsea. No. 1. Bush Villas is the site of Doctor Arthur Conan Doyle’s practice, 1882-1890. He created Sherlock Holmes here. In Rodin and Key, Medical Casebook of Doctor Arthur Conan Doyle: From Practitioner to Sherlock Holmes and Beyond, 1984.

We recommend commemorating Arthur Conan Doyle’s birthday, May 22, 1859, with a story or three from Round the red lamp: Being facts and fancies of medical life, with other medical short stories, available online, originally published in 1894 and reissued in 1992.

References
1. Conan Doyle, Arthur. “The Adventure of the Devil’s Foot.” His Last Bow. 1910. Project Gutenberg 15 May 2015. http://www.gutenberg.org/ebooks/2349

2. Alvin E. Rodin and Jack D. Key. Medical Casebook of Doctor Arthur Conan Doyle: From Practitioner to Sherlock Holmes and Beyond. Malabar, FL: Robert E. Krieger Publishing, 1984. p. 82.

3. D[oyle], A[rthur] C[onan]. “Gelseminum as Poison.” British Medical Journal 2: 483, 1879.

4.D[oyle], A[rthur] C[onan].

5. Doyle, Arthur Conan. “The Adventure of the Devil’s Foot.” His Last Bow. 1910. Project Gutenberg. 15 May 2015. http://www.gutenberg.org/ebooks/2349

6. Rodin and Key, 82.

7. Billings, Harold. “The material medica of Sherlock Holmes.” Baker Street Journal 55: 2006. 37-44.

8. Rodin and Key, 82.