Sherlock Holmes and the Case of the Poisonous Plants
Gather clues to link medicine, poison, and empire in the age of Sherlock Holmes.
Pharmaceutical Nursing Drug Kit (1910s) by Parke, Davis & CompanyScience History Institute
Take a close look at this kit
It has vials of plant toxins like strychnine, cocaine, morphine, and atropine. Who made use of such a kit? A murderer or perhaps a doctor?
Sherlock Holmes (1893)LIFE Photo Collection
Sherlock Holmes knew these drugs well
He solved mysteries involving powerful plants from across the world. Many plants produce alkaloids, chemicals that could be life-saving drugs or deadly poisons. Arthur Conan Doyle’s stories from 1887 to 1927 open a window on the history of medicine and empire.
Sir Arthur Conan Doyle (1901) by Mortimer MenpesScience History Institute
Doyle was a doctor before he became a writer
He first was a ship’s surgeon on a voyage to West Africa and later an ophthalmologist (eye doctor). In medical school Doyle took “practical botany” and was fascinated by poisonous plants. He even tested how much poison he could ingest before overdosing.
The Essentials of Materia Medica and Therapeutics Calabar (1877) by Alfred Baring GarrodScience History Institute
Toxicologist Robert Christison inspired Doyle’s self-experimentation. Christison studied the Calabar bean’s physostigmine alkaloid by swallowing it himself! His mouth watered and he sweated profusely, but he stopped before he suffocated in his own bronchial secretions.
A Manual of Vegetable Materia Medica No. 64, Physostigma venenosum seed (1886) by George S.V. WillsScience History Institute
In The Adventure of the Devil’s Foot (1910), Holmes investigates the death of a sister and brother that has left their two other brothers insane. Holmes deduces they were killed by a West African plant poison that affects the brain.
The poison is never explicitly named but its description matches the Calabar bean.
In southeastern Nigeria, known then as Old Calabar, the bean was used in witchcraft trials. If the accused person survived ingesting the poison, they were considered innocent. But by the 1880s, English doctors used it to treat glaucoma.
The Essentials of Materia Medica and Therapeutics Cover Page (1877) by Alfred Baring GarrodScience History Institute
Doyle owned a similar book, titled The Essentials of Materia Medica and Therapeutics. His copy has been preserved and digitized by the Harry Ransom Center at the University of Texas at Austin.
Doyle’s marginalia reflect his obsession with poison. Some pages have handwritten notes about the effects of drugs on human bodies. Doyle filled this page with playful poems about opium and tartar emetic.
A Manual of Vegetable Materia Medica A Manual of Vegetable Materia Medica (1886) by George S.V. WillsScience History Institute
Doyle wasn’t the only student learning about medicinal plants. The botanical illustrations in this story come from A Manual of Vegetable Materia Medica.
A Manual of Vegetable Materia Medica Westminster College of Chemistry and Pharmacy (1886) by George S.V. WillsScience History Institute
Students at the Westminster College of Pharmacy used this textbook to learn the intricate chemical processes involved in making medicine from raw plants.
A Manual of Vegetable Materia Medica Will’s Habitat Map (1886) by George S.V. WillsScience History Institute
Books of materia medica have existed since antiquity. But 19th century books featured many plants that came from the colonies of European empires.
Note the plants going in and out of England. What plants come from where you live?
Medicinal plants collection by RBG KewRoyal Botanic Gardens, Kew
The British Empire controlled more than a quarter of the world’s land by the late 1800s. Students at Westminster College and the detective at 221B Baker Street used plants that came from colonized places and conquered peoples.
Holmes and his "hyperdermic", with Dr. WatsonScience History Institute
Doyle’s stories often reference plants from British colonies. Holmes himself frequently used cocaine, an alkaloid extracted from the South American coca plant. Some scholars argue that Doyle used poisons and addictive drugs to suggest that colony life corrupted British officers.
Sherlock Holmes (1891)LIFE Photo Collection
Doyle described opium’s effects on British society in The Man With The Twisted Lip (1891). As Watson searches for his friend’s husband in an opium den, he finds Sherlock searching for another woman’s husband!
The men’s addictions to foreign vices threatened their reputations.
A Manual of Vegetable Materia Medica No. 16 & 17, Papaver somniferum mass (1886) by George S.V. WillsScience History Institute
Since the 1600s, opium from India was used in English medicines like laudanum. By 1803 pharmacists had learned to extract morphine from opium masses and believed they had tamed its addictive side. But they hadn’t.
While some in England became addicted to opium, the British Empire also used the plant as a tool of colonial control. The British cemented their economic presence by smuggling opium into China and giving samples to local people.
This had catastrophic effects on Chinese society as many became dependent on British opium.
Hand Book of Pharmacy and Therapeutics Views in the Pill Department (ca. 1919) by Eli Lilly and CompanyScience History Institute
Today’s pharmacists conjure up pictures of people counting pills made by corporations in faraway factories, like in this image. But until the mid 1800s, most drugs were created straight from plants one batch at a time.
Local pharmacists, called apothecaries back then, worked directly with botanical materials, creating the foundation for the present-day pharmaceutical industry.
Pharmaceutical Nursing Drug Kit (1910s) by Parke, Davis & CompanyScience History Institute
This brings us back to the kit we saw earlier. The vials actually held medicines manufactured by the pharmaceutical company Parke Davis.
Even the notorious strychnine tree could be used to heal. But higher doses can turn a medicine into a poison.
A Manual of Vegetable Materia Medica No. 134, Strychnos nux-vomica fruit (1886) by George S.V. WillsScience History Institute
In The Sign of the Four (1890), Holmes and Watson investigate the murder of a man guarding a hidden treasure taken from India by his father, a guard in the Andaman penal colony.
They discover he was killed by a blow dart coated in a strychnine-like poison, shot by an Andamanese Indian assistant to a former British officer.
Strychnine Sulfate Tablets (After 1870–Before 1910) by Eli Lilly and CompanyScience History Institute
The strychnine tree is indigenous to India, Sri Lanka, and Indonesia. People there used its seeds for centuries as a neurological, sexual, and digestive stimulant.
As trade between Europe and Asia expanded in the 17th century, strychnine became a popular household rat poison in England. By the Victorian period, physicians were studying its medicinal properties.
Hand Book of Pharmacy and Therapeutics Belladonna Farming (ca. 1919) by Eli Lilly and CompanyScience History Institute
When the first Sherlock Holmes story was published in 1887, drug production was just becoming industrialized. By the time the last story was published in 1927, expanding pharmaceutical companies farmed medicinal plants and extracted their alkaloids in factories.
The Essentials of Materia Medica and Therapeutics Slow Arsenic Poisoning (1877) by Alfred Baring GarrodScience History Institute
The era of Sherlock Holmes saw the final expansion of the British Empire. While imperial control gave the British access to powerful plants, it harmed people around the globe. The stories reveal the fascination and anxieties provoked by moving poisonous plants around the world.
Written and Curated by Nandini Subramaniam
Edited and Produced by Roger Turner
Audio Recording by Rigoberto Hernandez
Special thank you to:
Harry Ransom Center, The University of Texas at Austin
Wellcome Collection, London
