Kathleen Lonsdale transformed the field of organic chemistry. Just as notable, however, was her refusal to compromise her pacifist beliefs even when faced with a brutal backlash.
Scientists should take an interest in national and international affairs, not as politicians, but in making sure that facts are properly known, and in trying to ensure that science is used for good and not for evil purposes.
Crystallographer Kathleen Lonsdale (1903 – 1971) was one of the foremost scientists in UCL’s 200-year history. Born Kathleen Yardley, the youngest of ten to a poor but hardworking family in Ireland, she was dedicated to scientific endeavor from a young age. At the age of 16, while studying in London, she had to change to a boy’s’ school so she could continue to study physics, chemistry and maths, subjects unavailable to girls at the time.
In 1922 she graduated with a degree in Physics from Bedford College for Women, then part of the University of London. Gaining the highest marks in ten years, one of her examiners was so impressed he offered her a place on his research team at UCL – Nobel laureate and pioneering X-ray crystallographer, William H Bragg.
Lonsdale’s most significant discovery was in 1929, when she proved conclusively that the benzene ring had a flat, hexagonal structure. Scientists still use her methods today, and the impact of her discovery can be seen everywhere, from the development of safer, more effective drug treatments to the use of coloured fabrics in clothes and textiles.
When World War 2 broke out, Lonsdale was required to register for civil defence duties. A dedicated quaker and pacifist, she refused and was sentenced to one month in Holloway Prison. While there, she witnessed terrible treatment of women prisoners and her experiences led to her lifelong work in prison reform.
She was stoic in the face of persecution, continuing her scientific research and spending her evenings calculating X-ray diffraction patterns. “I managed to do about seven hours each day of really concentrated scientific work”, she later wrote.
In 1945, she became one of the first two female fellows of the Royal Society and, in 1949 she was appointed as UCL’s first female Professor.
Lonsdale was also proud of her family, sharing 3 children and 7 grandchildren, with husband Thomas Lonsdale, who she met at UCL. She retired in 1968, but she never wavered in her principles, campaigning for disarmament and peace until the end of her life.
Believing, as I do, in a God of love, I maintain that no-one and no nation is ever faced with a situation in which there is only a choice of evils. An end good in itself can never be reached by a method which involves the indiscriminate slaughter of guilty and innocent alike, which involves the starvation of children and the permanent injury of their minds and bodies.
Sources and explore further
- Lonsdale archives, UCL Special Collections
- The ethical science of Kathleen Lonsdale, The Royal Society
With contributions from Clare Carmalt, Professor of Inorganic Chemistry and Head of Department, and Lana Rawlings, PhD student and 2025 Ramsay Medal winner, both UCL Department of Chemistry.
Photo (top): Kathleen Lonsdale in her laboratory at UCL with structural models of minerals. Courtesy of The Royal Institution.
