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 Medical College of Calcutta. He is better known in engineering history: he later designed and built India's telegraph system and was knighted for it ^[1]. But in the late 1830s his interests were pharmacological. He observed that Indian practitioners—both Ayurvedic vaidyas and Unani hakims—routinely used cannabis preparations (bhang, ganja, and charas) for pain, sleep, appetite, and convulsions ^[2]. European medicine at the time had no cannabis equivalent, and O'Shaughnessy set out to test the drug systematically using the methods available to him.

The 1839 Paper and Methods

The work was first presented to the Medical and Physical Society of Calcutta in 1839 and printed as On the Preparations of the Indian Hemp, or Gunjah. An expanded version appeared in the Provincial Medical Journal in 1843. The paper has four main parts:

1. Literature review of Arabic, Persian, and Sanskrit sources on cannabis, drawn from translations available to O'Shaughnessy in Calcutta.
2. Botanical and chemical preparation: descriptions of ganja (flowering tops), bhang (leaves), and charas (resin), and methods for making an alcoholic tincture and resinous extract.
3. Animal toxicity studies: dosing of dogs, a kitten, fish, a vulture, and a crow with cannabis resin. He observed sedation, ataxia, and what he called a 'cataleptic' state, with no fatalities at the doses administered.
4. Human case reports: After the animal phase, he administered tinctures to patients at the hospital for rheumatism, hydrophobia (rabies), cholera, tetanus, and infantile convulsions.

The case reports are brief and uncontrolled by modern standards—no placebo, no blinding, no statistics—but they are dated, named, and dosed Strong evidence. This level of detail exceeded most contemporary medical publications, though it falls far short of modern clinical trial standards.

What O'Shaughnessy Claimed and What Evidence Shows

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'.

In retrospect:

Tetanus and rabies cures: did not hold up. Mortality from both diseases in 1839 was approximately 100%, and O'Shaughnessy's reported successes were not reliably reproduced by other 19th-century physicians Disputed ^[2]. Cannabis likely sedated patients and reduced involuntary spasm but did not address the underlying infection; rabies and tetanus remained essentially fatal until vaccines and antitoxins became available.

Anticonvulsant action: partially vindicated, much later. Modern randomized trials of cannabidiol (CBD) in Dravet and Lennox-Gastaut syndromes confirm that this cannabis-derived molecule suppresses certain seizure types ^[3] Strong evidence. O'Shaughnessy had no means to distinguish between THC and CBD effects; those molecules would not be isolated until the 1940s and 1960s ^[4].

Analgesia and antispasm: broadly supported by later evidence. Cannabis tinctures remained in the British and US pharmacopoeias through the early 20th century for these indications ^[2] Strong evidence. The United States Dispensatory and Materia Medica listed cannabis for migraine, neuralgia, insomnia, and dysmenorrhea ^[2].

Appetite, antiemetic, and sleep effects: consistent with later clinical observations, though O'Shaughnessy emphasized them less than spasm and seizure relief.

Dissemination and the Victorian Medical Cannabis Era

O'Shaughnessy returned to Britain in 1841 carrying samples of Indian cannabis, which he distributed to pharmacists including Peter Squire of London ^[2]. Squire's Extract of Cannabis became a widely sold commercial preparation, and cannabis extracts entered the United States Dispensatory by the 1850s ^[2]. By the 1880s and 1890s, cannabis tinctures were prescribed in Europe and America for migraine, neuralgia, insomnia, and menstrual pain.

J. Russell Reynolds, a prominent London physician, published observations on cannabis in The Lancet in 1890 for dysmenorrhea. Reynolds' work is the historical source of the often-repeated claim that 'Queen Victoria's physician prescribed cannabis to the Queen'—a claim that conflates documented clinical use with undocumented royal consumption. No primary document confirms that Queen Victoria herself used cannabis Disputed.

The 1894 Indian Hemp Drugs Commission Report, a comprehensive seven-volume British government inquiry, drew substantially on O'Shaughnessy's framing and conclusions when it reported that moderate cannabis use in India caused minimal social harm and recommended against prohibition.

Myths and Corrected Readings

'O'Shaughnessy discovered cannabis medicine.' False. He documented and clinically tested uses already standard in South Asian practice for centuries ^[2]. His contribution was translation into Western pharmacology and detailed case recording, not discovery Strong evidence.

'He proved cannabis cures rabies and tetanus.' Overstated. He reported apparent clinical successes in a small number of cases. Later clinicians could not replicate these results reliably, and both diseases remained essentially fatal until vaccines and antitoxins were developed Disputed.

'The 1839 paper started the modern cannabis industry.' False. It launched Victorian medical cannabis use, which largely collapsed by the 1930s due to regulatory prohibition and declining prescribing. The modern cannabis industry traces more directly to 1960s cannabinoid chemistry, 1970s activism around The Founding of NORML, and 1996 California Proposition 215 Strong evidence.

'O'Shaughnessy was a cannabis advocate.' Inaccurate framing. He was a curious imperial physician testing a local drug. He also worked on chloroform, prussic acid, electrochemistry, and telegraphy. Cannabis was one project among many scientific and engineering pursuits, not a career focus ^[1].

Why the Experiments Still Matter

The Bengal experiments remain historically and scientifically important for three reasons.

First, they are a documented transfer of knowledge. They provide a written, dated, dose-recorded bridge from Indian pharmacological practice into European medicine at a moment when most such transfers went unrecorded or were attributed to European 'discovery' ^[2]. This record is valuable for understanding how medical knowledge moved during the colonial era.

Second, they established a methodological template. O'Shaughnessy's approach—botanical identification, animal toxicity testing, then graded human dosing—became the standard framework for drug pharmacology and clinical development Strong evidence.

Third, they created a 70-year historical record. Victorian and Edwardian medical cannabis use, from the 1840s to the 1930s, generated clinical observations about dosing, side effects, and therapeutic indications. Modern researchers and regulators can draw on this historical data to understand how cannabis affects patients over time and at various doses Strong evidence. Modern clinical trials of cannabidiol in pediatric epilepsy, for instance, represent a return to one of O'Shaughnessy's original observations—but now with the molecular science and controlled methodology to test it properly.

Sources

How this page was made

Related

• The Founding of NORML — How Keith Stroup launched America's oldest marijuana reform lobby in 1970.