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Britain’s only living female Nobel laureate celebrated her 82nd birthday
this month. Although frail, Dorothy Crowfoot Hodgkin retains the spark and
joie de vivre that has propelled her through a distinguished scientific
career. Her vision of how chemistry and crystallography might combine
to reveal the biological workings of complex molecules would eventually
place the structures of insulin, penicillin and vitamin B₁₂ in her gifted
hands.

When I wrote to the University of Oxford to request an interview, the
reply was characteristically encouraging and swift. We met at her home,
a rambling Cotswold stone cottage in the Warwickshire village of Ilmington,
about 30 miles from Oxford. The atmosphere there is informal and friendly,
her cosy living room full of momentoes of foreign trips and paintings by
friends. As we talked, Star Trek: The Next Generation ran on, soundless,
in the background.

Hodgkin was born on 12 May 1910 in Cairo. Her father, John Crowfoot,
was an administrator in the British Education Service, which ran schools
for the children of British civil servants. Soon after her birth, the family
moved to the Sudan, where they remained until shortly after the outbreak
of the First World War. Dorothy and her two younger sisters were shipped
back to Worthing, in England, where their grandparents lived – although
they were cared for there by a nanny. Their parents remained in the Middle
East.

OXFORD BOUND

Hodgkin’s mother, Elizabeth, came to visit during and after the war.
Her father did not return to England for good until 1923. She spent most
of her secondary education at the highly academic Sir John Leman School
in Beccles, Suffolk, and took her school certificate in 1926, receiving
distinctions across a range of subjects, including chemistry. Her Oxford-educated
father lined her up for a place at Oxford almost before she was born, she
says. Hodgkin went to visit Somerville College with him and was told that
she needed to pass an entrance examination in two science subjects and Latin.

Admission to Oxford was not easy. Although Hodgkin had received distinctions
at school, standards for the entrance examination were much higher. But
with the help of private tutors and her old headmaster, who gave her lessons
in botany, she scraped through and went up to Somerville in October 1928.
The University of Oxford in the late 1920s was a very different place to
the establishment we know today. Women did not go out alone in the evenings.
‘We had to be chaperoned . . . and back in our rooms by nine o’clock,’ Hodgkin
recalls. ‘It was also extremely unusual in 1928 for a woman to read science.’

So why had Hodgkin decided to study chemistry? At the age of 15, during
a visit to the Sudan, she met a Dr Joseph, a government soil chemist who
was a friend of the family. He presented her with a chemistry set, and Hodgkin
remembers setting up her own mini-laboratory and experimenting with plants
that she had collected.

Today, Somerville is one of a rapidly diminishing number of women-only
colleges, and is shortly to admit men. In Hodgkin’s undergraduate days,
fewer than 5 per cent of women students at Oxford read a science subject.
The sciences were also taught in a different way. ‘Chemistry was particularly
unusual in that, thanks to a compulsory research year, the degree course
took four years instead of the usual three,’ she explains.

During her fourth year at Somerville, in the autumn of 1931, she first
began to specialise in X-ray crystallography. Her supervisor was H. M. (Tiny)
Powell, a young researcher in the subject. Powell’s research team numbered
just two – himself and Hodgkin. She was largely responsible for the gathering
of experimental data, which were then analysed under Powell’s supervision.
At the beginning of her research career their laboratory took up one corner
of a back room at the university museum in Parks Road. Halfway through Hodgkin’s
fourth year, Powell managed to persuade the authorities to let him take
over two rooms on the ground floor of the same building. They set up their
X-ray diffraction equipment in one and turned the other into a darkroom
for developing the plates.

‘The experimental technique of X-ray diffraction has changed utterly
since the 1930s,’ says Hodgkin. ‘Today, the process is largely automated
with computational methods completely revolutionising the mathematical analysis
of results. In 1932, the process was far more labour-intensive.’ The technique
was developed just after the outbreak of the First World War, when William
and Lawrence Bragg, the father and son team, used it to determine the simple
cubic structure of sodium chloride crystals.

If you shine a bright light through a fine grating you will see a pattern
– a diffraction pattern – caused by the deflection of light as it passes
through the regularly spaced slits in the grating. The same principle can
be applied to the regular structures of crystals, using X-rays instead of
visible light. X-rays have wavelengths that are similar to the spacing between
atoms in many crystals. Shining X-rays through a crystal produces a pattern
of dark points on ‘plates’ incorporating X-ray sensitive paper. This pattern
indirectly represents the arrangement of atoms in the crystal – in other
words, its structure. The experiments are straightforward, the analysis
difficult. The more atoms there are in the crystal, the more intricate the
analysis becomes. Hodgkin later pioneered the use of computers to handle
the complex mathematics involved in determining crystal structures by X-ray
crystallography.

PENICILLIN AND PERSEVERANCE

For most of the war years Hodgkin concentrated on penicillin – discovered
in 1928 but isolated in 1941 by Howard Florey – and in 1945 she elucidated
its structure before this had been deduced by purely chemical methods.
Then in 1956, after eight years’ work, she determined the structure of vitamin
B₁₂, which contains more than 90 atoms. This was considered by many at the
time to be the high point of X-ray diffraction analysis. Determination
of this structure was delayed because Hodgkin had to send her results by
surface mail to the US, where Kenneth Trueblood of the California Institute
of Technology in Pasadena did the computer analysis.

I asked Hodgkin about her ascent of the academic ladder. When did she
get her doctorate? ‘Not for many years,’ came the surprising reply. It was
only at this point that I began fully to realise just how unconventional
Hodgkin’s career had been. Not only had she leapfrogged the normal path
from undergraduate through doctoral research to fellow, reader and professorship,
but she had done her Nobel prizewinning research as a completely independent
scientist. At no point did she receive more than rudimentary funding from
the academic establishment and she had nothing to do with the normal academic
process of working in a team under a supervisory professor. Apart from a
brief sojourn in Cambridge, where she worked with the eminent X-ray crystallographer,
J. D. Bernal, from 1934 Hodgkin worked on her own, returning to the corner
of the back room at the university museum to conduct experiments with her
basic equipment. She also developed the exposed plates on which the diffraction
patterns were recorded and did her own analysis of them.

‘When I returned to Oxford in 1934,’ she explains, ‘I went to see Professor
(Robert) Robinson who, at the time, was one of the most eminent chemists
in the world and a very important man in Oxford. I wanted some financial
assistance and asked what he could do for me. He was very kind and genuinely
wanted to help me. He asked me to tell him what I needed, which was very
little compared with today’s standards. Within a few weeks he had acquired
a couple of goniometers for me, and that’s really all I needed to set up
in business.’ (A goniometer is an instrument for measuring the angles between
the faces of a crystal.)

I asked her if she had ever worried about the effects on her health
of her research with X-rays. ‘I had such fears only once, when I first returned
to Oxford in 1934 and had serious thoughts of marriage. For a while I had
feared that radiation might possibly have affected my fertility, but I was
reassured by the fact that the pioneers of X-ray diffraction, the Braggs,
were a father and son team. I also sought the advice of some physicist friends
who convinced me that I should not worry.’

In retrospect, she was probably very lucky. In 1958, the great X-ray
crystallographer Rosalind Franklin died of cancer at the age of 37. Her
illness is thought to have been caused partly by her exposure to X-rays.

In 1937, Dorothy Crowfoot married the historian Thomas Hodgkin and started
a family. For a number of years she managed to juggle the demands of parenthood
– she had three children – and her position as tutor at Somerville. She
enjoyed teaching and devoted up to 10 hours a week to the task. With her
salary she bought essential equipment. She taught Margaret Thatcher and
remembers her as a less than inspired chemist who, although quite competent,
had no real feel for the subject.

THE TOP OF THE ACADEMIC LADDER

Hodgkin was made Royal Society Wolfson Research Professor in 1960, a
post she held until her 66th birthday in 1976. Her professorship came from
the Royal Society thanks to an annual prize bestowed by the philanthropist
Isaac Wolfson. The story goes that the treasurer of the society, the physicist
William G. Penney, invited Wolfson to lunch to try to persuade him to help
finance a commemorative Royal Society party scheduled for later that year.
By some unknown means, Penney had acquired two bottles of Coca-Cola, a
rare commodity in Britain at the time and a favourite of Wolfson’s. At
the luncheon, Penney produced one bottle of Coca-Cola between the starter
and the main course. Wolfson was so pleased that he offered Penney the
money needed for the party. Upon delivering a second bottle to the astonished
millionaire, Penney was granted annual funding for a Royal Society professorship,
later awarded to Hodgkin.

Hodgkin developed arthritis in her early fifties and the labour-intensive
nature of her work forced her to retire from practical research in the early
1960s. But she carried on teaching until the early 1970s, and her research
was still bearing fruit. Her formative encounter with computers was in 1946,
on a three-month visit to California, where she worked with Hans Clarke,
Robert Woodward and Linus Pauling. Computers could be programmed to produce
electron-density maps, a time-consuming part of the analysis. This advance
made a large contribution to the elucidation of vitamin B12 in 1956. Computer
technology eventually caught up with Hodgkin’s research, and in 1969, with
its help, she finished the work she had begun more than 30 years before
and determined the structure of insulin, a compound that contains more than
800 atoms.

Tom Blundell, now director-general of the Agricultural and Food Research
Council and a professor in the University of London, worked on insulin
as a young researcher in Hodgkin’s laboratory. He recalls her gentleness
as well as her great vision. ‘She was very intuitive in her science . .
. she was always right. I would be convinced that I had the right approach.
She would suggest a different one and much later I would find she was right
after all.’ She had, he says, clear objectives when she chose to study the
crystals whose structure she eventually unravelled. She believed that their
biological function would be revealed through their crystal structure. ‘Each
was a challenge crystallographically, but the confidence was there; she
thought it could be done, and she was willing to persevere for years.’ She
was always keen to foster international collaboration; Blundell remembers
her laboratory as being ‘full of foreigners’, researchers from all over
the world.

She was made a Fellow of the Royal Society in 1947 and won The Nobel
Prize for Chemistry in 1964, the same year that Martin Luther King won the
peace prize. She has been awarded honorary doctorates by numerous universities
worldwide as well as the Lomonosov Gold Medal of the Soviet Academy of Sciences
in 1983.

In retirement from active research she travelled extensively. She became
a prominent worker for international peace and understanding; between 1976
and 1988 she presided over the regular Pugwash conferences, at which scientists
discuss world problems. During this time she frequently visited the Soviet
Union and the Far East. In 1965 she became the first woman since Florence
Nightingale to be awarded the Order of Merit and, 20 years later, her portrait
joined a very small band of scientists in the National Portrait Gallery.
Undoubtedly, Dorothy Hodgkin can live out her old age with great pride in
an extraordinary lifetime of achievement.

Michael White is a freelance writer based in Oxford.