History of science

Five Titans of Science with a London Connection

Five people whose discoveries changed how we understand the human body, disease and life itself.

By Dave Hart

Vice President of Onyx

3 min read

London, Palace of Westminster -- 2016 -- 4800 (opens in a new tab)

Photo: Dietmar Rabich (opens in a new tab) / Wikimedia Commons (opens in a new tab)

Licence: CC BY-SA 4.0 (opens in a new tab)

Changes: cropped.

London has witnessed an extraordinary number of hugely significant medical discoveries which have changed the way we understand the human body, disease and the basic machinery of life. All five of the people here have connections with London - how many do you know?

1. William Harvey - the man who discovered the circulation of blood

In the early 17th century, most people believed the heart worked rather differently from the way we understand it today. William Harvey, a physician who studied and later taught at St Bartholomew’s Hospital, challenged centuries of accepted wisdom. In 1628 he demonstrated that the heart pumps blood around the body in a continuous circulation. It was a revolutionary idea - and one that could be tested by observation rather than simply accepted because ancient authorities had said so.

2. Joseph Lister - the surgeon who made operations safer

It’s hard to imagine surgery before anyone understood infection, but for centuries that is the way it was. A successful operation could often be followed by a fatal infection. Joseph Lister, who studied medicine at University College London and later became Professor of Clinical Surgery at King’s College London, changed that. Inspired by Louis Pasteur’s work on microorganisms, he introduced antiseptic techniques using carbolic acid. His work helped transform surgery from something desperately dangerous into a much more controlled science. He’s now widely regarded as a father of modern surgery.

3. Alexander Fleming - the lucky accident

In 1928, at St Mary’s Hospital in Paddington, Alexander Fleming noticed something unusual in a discarded laboratory culture: mould had killed the bacteria around it. The substance became known as penicillin. Fleming’s observation was only the beginning - Howard Florey, Ernst Chain and their colleagues later developed methods for producing it on a scale that could treat patients. But Fleming’s discovery marked the dawn of the antibiotic age and ultimately saved millions of lives.

Alexander Fleming at his laboratory bench at St Mary's Hospital, Paddington, holding a culture dish. — Alexander Fleming in his laboratory at St Mary's, Paddington, where he discovered penicillin.

Fleming’s discovery marked the dawn of the antibiotic age and ultimately saved millions of lives.

4. Rosalind Franklin - Photograph 51

At King’s College London in 1952, Rosalind Franklin and her PhD student Raymond Gosling produced the extraordinary X-ray diffraction image known as Photograph 51. It revealed crucial evidence that DNA had a helical structure and became an important part of the evidence behind the double-helix model developed by James Watson and Francis Crick. Franklin subsequently moved to Birkbeck in London, where her work on viruses helped establish structural virology.

The King's Building of King's College London on the Strand, which houses the Great Hall. — The King's Building, King's College London Strand Campus - home of the Great Hall.

5. Francis Crick - discovering the code of life

Crick was one half of the partnership that produced the famous 1953 model of DNA’s double helix. He was educated at University College London before his wartime scientific work and later research at Cambridge. The DNA breakthrough fundamentally changed biology: once scientists understood how genetic information was stored, the door opened to modern molecular biology, genomics and biotechnology.