Cannabis at the 1839 Bengal Experiments

Background: O'Shaughnessy in Calcutta

William Brooke O'Shaughnessy was an Irish-born physician and chemist who joined the East India Company's medical service in 1833 and took a chair at the new Medical College of Calcutta ^[1]. He is better known to engineers than to doctors: he later built the Indian telegraph system and was knighted for it ^[2]. But in the late 1830s his interests were pharmacological. He observed that Indian practitioners — both Ayurvedic vaidyas and Unani hakims — routinely used preparations of cannabis (bhang, ganja, and charas) for pain, sleep, appetite, and convulsions ^[1][3]. European medicine at the time had no equivalent in its formulary, and O'Shaughnessy set out to test the drug systematically.

The 1839 paper

The work was first read before the Medical and Physical Society of Calcutta in 1839 and printed locally as On the Preparations of the Indian Hemp, or Gunjah ^[1]. An expanded version appeared in the Provincial Medical Journal in 1843 ^[4]. The paper has four parts:

1. A literature review of Arabic, Persian, and Sanskrit sources on cannabis, drawing on translations available to him in Calcutta.
2. A botanical and preparative section describing ganja (flowering tops), bhang (leaves), and charas (resin), and his method for making an alcoholic tincture and a resinous extract.
3. Animal experiments. He dosed dogs, a kitten, fish, a vulture, and a crow with the resin and described sedation, ataxia, and what he called a 'cataleptic' state, with no fatalities at the doses used.
4. Human cases. After satisfying himself the drug was not lethal in animals, he administered the tincture to patients at the college hospital for rheumatism, hydrophobia (rabies), cholera, and most famously tetanus and infantile convulsions ^[1][4].

The case reports are brief and uncontrolled by modern standards — there were no placebos, no blinding, no statistics — but they are dated, named, and dosed, which made them unusually rigorous for 1839 Strong evidence.

What he claimed, and what held up

O'Shaughnessy reported dramatic relief of muscle spasm in tetanus and rabies patients, sometimes accompanied by what he described as a 'singular state of catalepsy.' He concluded cannabis was 'an anti-convulsive remedy of the greatest value' ^[1][4].

In hindsight:

• Tetanus and rabies cures: didn't hold up. Mortality from these diseases in 1839 was effectively 100%, and his apparent successes were not reproduced reliably by later 19th-century physicians Disputed. Cannabis likely sedated patients and reduced spasm but did not alter the underlying infection.
• Anticonvulsant action: partially vindicated, much later. Modern trials of cannabidiol in Dravet and Lennox-Gastaut syndromes confirm that a cannabis-derived molecule does suppress certain seizures ^[5] Strong evidence. O'Shaughnessy had no way to know he was seeing a CBD effect rather than a THC effect — those molecules would not be isolated until the 1940s and 1960s ^[6].
• Analgesic and antispasmodic use: broadly supported. Cannabis tinctures remained in the British and US pharmacopoeias for these indications into the 20th century ^[3][7].
• Appetite, antiemetic, sleep effects: consistent with later evidence, though O'Shaughnessy gave them less emphasis.

How the work spread

O'Shaughnessy returned to Britain in 1841 carrying samples of Indian hemp, which he distributed to pharmacists including Peter Squire of London. Squire's Extract of Cannabis became a widely sold preparation, and Queen Victoria's physician J. Russell Reynolds later prescribed cannabis tincture (this is the source of the often-exaggerated 'Queen Victoria used cannabis for cramps' claim — Reynolds wrote about its use for dysmenorrhea in The Lancet in 1890, but there is no primary document confirming the Queen herself took it) ^[7] Disputed.

By the 1850s, cannabis extracts appeared in the United States Dispensatory and were prescribed in Europe and America for migraine, neuralgia, insomnia, and menstrual pain ^[3][7]. The 1894 Indian Hemp Drugs Commission Report, a seven-volume British government inquiry, leaned heavily on O'Shaughnessy's framing when it concluded that moderate cannabis use in India caused little social harm ^[8].

Myths and misreadings

Several claims circulate online about the Bengal experiments that overstate or distort the record:

• 'O'Shaughnessy discovered cannabis's medical use.' He did not. He documented and tested uses already standard in South Asian medicine for centuries ^[3][8]. His contribution was translation into Western pharmacology, not discovery Strong evidence.
• 'He proved cannabis cures rabies/tetanus.' He reported promising cases. Later clinicians could not replicate the cures, and both diseases remained essentially fatal until vaccines and antitoxins Disputed.
• 'The 1839 paper started the modern cannabis industry.' It started Victorian medical cannabis, which collapsed by the 1930s. The modern industry traces more directly to 1960s cannabinoid chemistry, 1970s NORML-era activism, and 1996 California Proposition 215 Strong evidence.
• 'O'Shaughnessy was a cannabis advocate.' He was a curious imperial scientist testing a local drug. He also worked on chloroform, prussic acid, and electrochemistry. Cannabis was one project among many ^[2].

Why the experiments still matter

The Bengal experiments matter for three reasons. First, they are a documented bridge: a written, dated, dose-recorded transfer of pharmacological knowledge from Indian practice into European medicine, at a moment when most such transfers went unrecorded. Second, they established a template — botanical identification, animal toxicity, then graded human dosing — that would become standard pharmacology. Third, they seeded a roughly 70-year window of Western medical cannabis use, which gives modern researchers and regulators a historical record of side effects, dosing ranges, and clinical indications to draw on. For more on what followed, see Cannabis in Victorian medicine and the 1894 Indian Hemp Drugs Commission.

Sources

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