From Alliston, London, Ontario
The farm boy who solved diabetes on a hot July morning
On July 27, 1921, a farm boy from Alliston solved diabetes.
Every diabetic person alive today is alive because of what he and his young assistant did that morning in a Toronto laboratory that smelled faintly of dogs.
- Born: November 14, 1891, in Alliston, Ontario
- Grew up: on the family farm just outside Alliston, in Simcoe County — potato country, about an hour north of Toronto
- Died: February 21, 1941, in a plane crash off Musgrave Harbour, Newfoundland, aged 49, while carrying wartime medical research to Britain
- Discovery: insulin — isolated with Charles Best on July 27, 1921, at the University of Toronto
- Nobel Prize in Medicine: 1923, shared with J. J. R. Macleod
- Patent for insulin: sold to the University of Toronto for one dollar
- Sir Frederick Banting Homestead: the farm where he grew up, outside Alliston — a National Historic Site of Canada
The Alliston farm boy
Frederick Grant Banting was born on November 14, 1891, in a small farming town in Simcoe County called Alliston — an hour or so north of Toronto, in what was then, and is still, potato country. He was the youngest of five.
He grew up on the family farm. He milked cows before school and drew anatomy sketches at night. He originally wanted to be a small-town doctor. His parents wanted him to be a minister.
He went to medical school at the University of Toronto and served as a medical officer in the First World War. He was wounded at Cambrai in 1918 and continued to treat wounded soldiers for another sixteen hours before he was ordered to stop. He was awarded the Military Cross.
After the war he opened a private practice in London, Ontario. It was not a busy practice. He supplemented his income teaching anatomy at the University of Western Ontario.
The idea, October 1920
One October night in 1920, preparing a lecture on the pancreas, Banting read a journal article about pancreatic surgery and could not stop thinking about it.
He got up in the middle of the night, took out a notebook, and wrote down twenty-five words describing an experiment. If a piece of the pancreas was tied off, the digestive tissue would waste away — but the mysterious cells known as the islets of Langerhans, which some researchers suspected produced an internal secretion, might survive long enough to be extracted.
It was a small idea. It was written on one page. It changed the world.
He took the note to J. J. R. Macleod at the University of Toronto the following spring. Macleod was skeptical, but he agreed to let Banting have a laboratory for the summer of 1921, along with a young medical graduate as an assistant.
The assistant was Charles Best, twenty-two years old.
The Toronto laboratory, summer 1921
It was a small laboratory. The elevator smelled of dogs. The equipment was borrowed. It was, in every practical sense, a very small-town operation running inside a big city.
The team was Banting and Best, working alone through the summer. Macleod left for a research trip to Scotland. The heat was punishing. The dogs were expensive. Their money ran out more than once.
On July 27, 1921 — a hot Wednesday morning — they successfully isolated the hormone from a dog pancreas and injected it into another dog whose pancreas had been removed. Within an hour, the second dog’s blood sugar dropped. Within a day, its symptoms of diabetes had reversed.
They had done it.
A biochemist named James Collip joined the team in the fall to figure out how to purify the extract for human use. Within months, they had a version safe enough for clinical trials.
On January 11, 1922, a fourteen-year-old boy named Leonard Thompson at Toronto General Hospital was given the first human insulin injection. It caused a severe allergic reaction — the extract had not yet been purified enough. Twelve days later, on January 23, 1922, after Collip refined the extraction further, Thompson received a second dose. That one worked. It saved his life. Word spread across the world in weeks.
The dollar patent
In 1923, Banting and Macleod were awarded the Nobel Prize in Medicine. Banting was furious that Best had been left off the citation. He quietly split his half of the prize money with Best. Macleod, hearing what Banting had done, split his half with Collip.
It is the only Nobel Prize in history that four scientists effectively shared.
Banting was thirty-two years old. He was the youngest Nobel laureate in the category of Physiology or Medicine at the time. He remained the youngest Canadian Nobel laureate for decades.
He and his partners then sold the patent rights to insulin to the University of Toronto for one dollar each. They wanted the drug to be manufactured widely and cheaply, so that no diabetic person anywhere would be denied it.
“Insulin does not belong to me,” Banting said. “It belongs to the world.”
A century later, the affordability of insulin remains an active question in many countries. But the price of the patent has never changed.
The painter
Banting kept a small studio at the family farm in Alliston, and later, a second one in Toronto. He painted, badly, throughout his life. He never claimed otherwise.
His painting friends were a small circle including A. Y. Jackson and other members of the Group of Seven. In 1927, he joined Jackson on a sketching trip to the eastern Arctic aboard the Canadian government supply ship SS Beothic. Two summers later he went again, this time above the Arctic Circle.
What he saw on those trips he could not paint well. He painted them anyway.
It is one of the more human details of his life. A man who could quietly change the world in a laboratory did not need to be good at everything else.
Newfoundland, February 21, 1941
When the Second World War broke out, Banting was commissioned a Major in the Royal Canadian Army Medical Corps. He became chair of the National Research Council’s Associate Committee on Aviation Medical Research and served as coordinating officer for Allied wartime medical work — conducting cold-weather and high-altitude tests himself.
In February 1941, he boarded a Hudson bomber at Gander, Newfoundland, carrying wartime medical research to Britain. The plane crashed shortly after takeoff, near Musgrave Harbour on Newfoundland’s northeast coast. Banting survived the crash but died of his injuries the next day.
He was forty-nine years old.
The Homestead
The Sir Frederick Banting Homestead — the farm where he grew up, just outside Alliston, Ontario — is a National Historic Site of Canada. Visitors can walk the fields, see the barn, and stand on the porch of the farmhouse where a small-town boy once decided to become a doctor.
On July 27 every year, someone puts fresh flowers on the porch.
Both are ways of noticing
Banting’s story sits four summers after another quiet Canadian one. In July 1917, Tom Thomson — a small-town Ontario boy from Claremont, painting the wilderness at Canoe Lake — did not come back from a morning on the water. Four summers later, another small-town Ontario boy, from Alliston, sat in a hot Toronto laboratory and looked inside a pancreas.
One had been teaching a country how to look at a jack pine. The other, on that hot Wednesday in July 1921, was teaching it how to look at a molecule.
Both are ways of noticing.
Both start on a farm somewhere.
Both belong to all of us now.
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Read Castor’s July 27, 2026 letter about the small towns that made two Canadians on the same summer weekend: Who Painted Tom Thomson?
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Alliston, Ontario
Alliston is a small farming town in Simcoe County, Ontario, about an hour north of Toronto. Once its own municipality, it is now part of the Town of New Tecumseth (amalgamated in 1991 with Beeton, Tottenham, and the Township of Tecumseth). The town remains at the heart of Ontario’s potato country. It is best known for two things: the Honda of Canada Manufacturing plant on its eastern edge, which builds Civics and CR-Vs — and the small farmhouse just outside town where a boy once slept with a notebook by his bed.
