Kathleen (Yardley) Lonsdale DSc., FR

JMS Pearce
Hull, England


Dame Kathleen Lonsdale (née Yardley)
Fig 1. Dame Kathleen Lonsdale (née Yardley) by Elliott & Fry. 1996. National Portrait gallery. CC BY-NC-ND 3.0

Kathleen Lonsdale (1903-1971) (Fig 1) like her contemporary Dorothy Hodgkin was one of the women pioneers in a man’s world of professional scientists.1 She developed original techniques in X-ray diffraction of crystals to determine the structure of a molecule. This led to studies of the benzene ring, structure of drugs, and investigations of urinary stones.

She was born Kathleen Yardley in Newbridge, County Kildare in Ireland, the youngest of ten children. The impecunious family had no Quaker roots: her father, Harry, was a retired soldier working as a postmaster; her mother, Jessie, was a Scottish Baptist.

After a family upheaval, her mother moved to Essex, where Kathleen won a scholarship to the County High School for Girls at Ilford; she then won a county scholarship. This enabled her to attend Bedford College for Women in London at the age of sixteen to study mathematics,but she soon switched to physics. In 1922 she came first in the honors B.Sc. examination. W.H. Bragg, a pioneer of X-ray diffraction and Nobel Laureate,a was so impressed that he offered her a place in his research group at University College, London.

Kathleen used X-ray diffraction to determine the structure of a molecule by analyzing how a crystal formed by that molecule would scatter a beam of X-rays. She was an excellent experimenter in the tradition of Michael Faraday and in addition to her own discoveries spent time working to provide standardized mathematical tables for crystal structures. In 1923 Bragg moved to the Royal Institution and took Kathleen Yardley with him. (Similarly in 1937 he invited Hodgkin to the Royal Institution to advance her investigation of insulin by crystallography.)

She met Thomas Lonsdale, a research student at University College. In 1927 they married and moved to Leeds. They had three children: Jane, Nancy, and Stephen. She was appointed Amy Lady Tate Scholar and part-time demonstrator at Leeds University.

There, she investigated crystals of hexamethyl benzene and showed that the benzene ring (an essential component of organic compounds) is flat and hexagonal.3 In Kendal, a Quaker embroidery exhibition shows Lonsdale with a diagram of the benzene ring. Whilst in Leeds, gravely troubled by the horrors of warfare, she became a Quaker. At the outbreak of the Second World War she became a conscientious objector and like many Quakers was fined; she was sent to Holloway gaol for one month but this blunted neither her scientific ardor nor her religious beliefs. In 1931 she returned to the Royal Institution and continued her research there for fifteen years. She obtained the DSc., University College, London in 1936.

Reflecting the importance of her crystallography, on 22 March 1945 Kathleen Lonsdale and Marjory Stephenson were elected the first women Fellows of the Royal Society. (Dorothy Hodgkin was elected one year later.) Lonsdale was later the first woman President of the British Association for the Advancement of Science in 1968. She was appointed Professor of Chemistry and head of UCL’s Department of Crystallography in 1949. She was awarded the Davy Medal of the Royal Society in 1957 and three years later became its Vice-President. From 1960-66 she was Vice-President, and in 1966, President of the International Union of Crystallography.

In later years she expanded her work into solid-state reactions,b the chemical structure of drugs, and the constitution of bladder and renal stones.4 Using X-ray diffraction she showed that there are several kinds of human urinary calculi, with different age, sex, and geographical distributions. She noted that juvenile bladder stones are typically urate and oxalate; the common adult stones are mainly calcium oxalates and calcium and MgNH4 phosphates. Exercise and drinking more water might prevent kidney dehydration and lower the incidence; moderate acidification would prevent phosphate supersaturation of the urine.

In 1966 Lonsdaleite, a rare form of diamond derived from meteors, was named after her. These are just a few of her discoveries that have been assimilated into modern chemistry. Some found clinical applications. She edited the International Atlas for X-ray Crystallography. Lonsdale wrote many esteemed papers, including a monograph, Crystals and x rays, in 1948.5 She trained countless students in the techniques and made many contributions to science,6 the education of schoolchildren, and medicine.

She vigorously promoted pacifism and supported the foundation of the Pugwash Movement.c She served as Vice-President of the Atomic Scientist’s Association and President of the Women’s International League for Peace and Freedom. In popular demand as a scientific speaker, she also lectured on non-scientific topics in Britain and abroad.

In the early 1930s she left research temporarily to care for her small children and from home devised the crystallographic reference tables. Based on her experiences, she focused on issues of marriage and family when speaking about women in science during the late 1960s. The Dame Kathleen Lonsdale Papers at University College London argue that her scientific career was shaped by her identity as a married woman and a mother. Amongst her scientific colleagues, Lonsdale frequently had to confront the assumption that married women should not pursue scientific careers, an attitude shaped by reasserted gender roles after World Wars I and II.

She was made a Dame Commander of the Order of the British Empire (DBE) in 1965. When her husband retired in 1960, they worked together for peace and prison reform. In 1970 she developed cancer and died in hospital on April 1, 1971.

She is commemorated in her native Kildare at the National University of Ireland, Maynooth, by the Lonsdale Prize, awarded to the student obtaining the best First Class Honors degree in chemistry. In 1981 the chemistry building at University College was renamed the Kathleen Lonsdale Building. And in 1998 the new Aeronautical and Environmental Building at the University of Limerick was officially named the Kathleen Lonsdale Building, marking her Irish birth.

Her contemporary and friend Dorothy Hodgkin, Nobel Laureate in Chemistry, said of her:

“There is a sense in which she appeared to own the whole of crystallography in her time.”


End Notes

  1. WH Bragg uniquely shared the Nobel Prize with his son Lawrence Bragg—the 1915 Nobel Prize in Physics: “for their services in the analysis of crystal structure by means of X-rays.”
  2. The study of the structure and physical properties of solids, used in synthesis of drugs and their physical and chemical transformations.
  3. The Pugwash Conferences take their name from their first meeting in 1957 in the village of Pugwash, Nova Scotia. Their aim was to bring together, from around the world, influential scholars and public figures concerned with reducing the danger of armed conflict.



  1. Childs PE. The life and work of Dame Kathleen Lonsdale (1903-1971). A Lecture to mark the official opening of the Kathleen Lonsdale Building, University of Limerick 20th. April 1998.
  2. Reville W. Kathleen Lonsdale – Famous Irish Scientist. The Irish Times, (December 13, 2001.)
  3. Hodgkin D. Kathleen Lonsdale, 28 January 1903 — 1 April 1971. Biographical Memoirs of the Royal Society 1975;41:447 https://royalsocietypublishing.org/doi/pdf/10.1098/rsbm.1975.0014.
  4. Lonsdale K, Mason P. Uric Acid, Uric Acid Dihydrate, and Urates in Urinary Calculi, Ancient and Modern. Science 1966;152 (3728), 1511-1512.
  5. Lonsdale K. Crystals and X-Rays. G. Bell & Sons, London, 1948.
  6. Julian MM. Dame Kathleen Lonsdale (1903-1971). Journal of Chemical Education 1982;59:965.



JMS PEARCE, MD, FRCP, is an Emeritus Consultant Neurologist, Department of Neurology, Hull Royal Infirmary, and an author with a particular interest in the history of science and medicine.


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