Dorothy Hodgkin

by Kristin Thiel

  By December 1912, Lawrence Bragg, only twenty-two years old, was the first person to solve the atomic structure within a crystal. He wrote to his dad, William, that it had all been right in front of Laue. Laue could have gotten it had he been approaching the puzzle from this angle. Lawrence thought it was a lot of fun that he had figured it out.

  William Bragg developed the X-ray spectrometer to get a better handle on this. A narrowly focused X-ray could be shot at a crystal suspended in the machine. By adjusting the angle of the X-ray, Bragg worked his way around the crystal. He measured not only the angle the light shot from the crystal but the intensity with which it shot. Different angles produced different intensities. Using his son’s calculations, he realized he was seeing the arrangement of atoms. Try this yourself by playing with the angles of X-rays (the lines) and the spacing of atoms (the blue dots) in this interactive image: http://www-outreach.phy.cam.ac.uk/camphy/xraydiffraction/xraydiffraction_exp.htm.

  Maybe at this point we should imagine Dorothy Hodgkin as her friend and colleague Max Perutz described her in his obituary of her. He said that often a dreamy look would cross her face during meetings, as all the scientists around the table discussed and argued about the problem at hand and its possible solutions. And then without warning she’d speak, some spot-on observation that no one else had seen. She might have been considered a know-it-all except that she presented so warmly, her corrections of others’ work always followed by a little laugh to soften her words.

  Hodgkin always followed the thrill of the chase, the excitement of following the math and the science along a twisting journey to, ultimately, a rewarding conclusion, completely logical in its existence but completely surprising.

  INSPIRING CONTEMPORARIES

  Hodgkin came from a line of scientists who thrilled to the chase—after all, that’s what scientists do! But it is particularly exciting to learn of women’s professional advances because for too long we haven’t heard much about any scientific work by women.

  Polly Porter

  Mary “Polly” Porter worked during Hodgkin’s time. She had been assistant to Henry Alexander Miers, the man who transformed Oxford University’s mineralogy department into a crystallography lab in the late 1800s. Porter had a surprisingly long effect on X-ray crystallography and became an inspiration to Hodgkin.

  Porter’s influence was surprising in large part because she left school before she was fifteen. Her parents didn’t think she needed an education, but they couldn’t stop her from learning on her own. She did such a good job with her self-designed study that she ended up unintentionally impressing Miers. He took notice of her regular visits to the Oxford Museum’s collection of antique Italian marbles and asked if she could translate the catalog from Italian. She could.

  Despite such a well-known academic being in their daughter’s corner, Porter’s parents refused to let her attend Oxford. That attitude continued to have little actual effect on her life. She continued to be offered, and to happily take, research opportunities not only in England but also in the United States and Germany, and eventually she found herself working in X-ray crystallography. Miers simply asked her if she would like to try growing some crystals. Encouragement is an important component to someone’s education being a success. Porter published in respected journals and coedited the three-volume Barker Index of Crystals.

  Kathleen Lonsdale

  Also one of Hodgkin’s contemporaries, Kathleen Lonsdale became well known in their shared field of crystallography. “There is a sense in which she appeared to own the whole of crystallography in her time,” Hodgkin once said of her. Like Hodgkin, Lonsdale worked under William Bragg and upheld his legacy. Hodgkin looked up to her, not only for her success but also for the fact that Lonsdale continued to work while raising three children. In turn, Lonsdale admired Hodgkin’s ability and played a role in Hodgkin’s penicillin research by growing, and even transporting, some crystals Hodgkin used.

  Given the era in which she lived, Lonsdale was lucky when it came to her success. With a scholarship, she attended a girls’ high school, but she had to take some of her classes at the boys’ school—physics, chemistry, and math simply weren’t offered at her school. She was the only one of the ten children in her family who went to high school. Back then, education wasn’t as common as it is now. A lot of people we would consider of school age today were, as late as the mid-1900s, already working full-time jobs. Her siblings left school to work in order to support their family.

  Hodgkin greatly admired her colleague in crystallography, Kathleen Yardley Lonsdale, not only for her research but for her ability to keep working while raising a family.

  In later life, physicist Lonsdale blazed many trails. For instance, she was one of the first women to be elected to the Royal Society and was the first female professor to be given a permanent position at University College London. She was the first to apply the Fourier mathematical methods to analyze X-ray patterns to atomic structure. In another exciting project, Lonsdale ended a sixty-year-old argument about the benzene ring, the six carbon atoms of benzene, arranged in a circle: yes, it was flat.

  Margery Fry was a major influence on Hodgkin—in her schoolwork and her interest in social advocacy.

  CHAPTER

  FOUR

  OBSTACLE COURSES AND SUPPORT SYSTEMS

  Crystallography had an uphill battle to widespread public acknowledgment. X-ray crystallography is less visible to most people than the work of people such as Marie Curie and Albert Einstein. (Although isn’t that rather perfect, that a technique used to see the unseeable is itself unseen?)

  Hodgkin was herself low-key, even though she was one of the most well-known crystallographers. She chose projects not for the possibility of fame or money. She was fascinated in the science and if a structure would be interesting to investigate. She never wrote a book, led a glitzy laboratory, or listed any of her awards and honors as part of her name.

  CRITICISMS OF CRYSTALLOGRAPHY

  Early crystallographers faced some critics. Sometimes, the biggest arguments came from people who weren’t experts in science. Johann Wolfgang von Goethe—who wrote the classic Faust, among many other pieces—was a renowned literary figure even when he was alive, in the late 1700s and early 1800s. For a while, he fancied himself a scientific thinker and criticized crystallography as having “no practical influence in a living context; for its most precious products, crystalline gems, first have to be cut and polished before we can use them to adorn our womenfolk.” Wouldn’t he have been surprised to have met Hodgkin, who did not wear her gems but studied them?

  As early as 1895, the year X-rays were discovered, Geological magazine was supporting crystallography. Goethe knew crystallography before its geometrical principles had been fully established and when the technique was still used in mineralogy alone. By the turn of that century, chemistry, petrology, and geology made use of crystallography. Later, crystallography occasionally heard from detractors. Henry Armstrong, a chemist, responded to William Bragg in Nature in 1927, saying that X-ray physics offered false hope.

  A MIXED RESPONSE TOWARD WOMEN IN THE FIELD

  Men Supporting Women

  Hodgkin repeatedly stated that being a woman did not cause her problems at work. Helen Megaw, who studied at Cambridge with Dorothy, agreed with that statement. There is a general consensus that X-ray crystallography was “largely hospitable” to scientists who were women.

  Many men support women in the sciences (and in life) by being allies, both by speaking up for women and by getting out of their way so they can make their own choices and take leadership. Mathematical crystallographer Maureen Julian has done several studies of her field. In one, she listed all the scientists directly “related” through work to Braggs; as of 1990, he’d had a direct effect on fifty crystallographers who were women.

  Peter Lyttle, a program coordinator for the United States Geological Survey (USGS), shared a story about one of the women in Hodgkin’s extended “family” of
mentors, Florence Bascom, the first woman the USGS ever hired. In the 1980s, Lyttle was mapping some land, which required him to do physical work outside. One day, a man stopped his car and engaged Lyttle in conversation. Why was he messing with Bascom’s work, the man demanded to know. Bascom had worked at a turning point in geology; she prepared folios, geologic maps of areas for the USGS, and also worked at the microscopic level of the study of rocks. Lyttle quickly explained he was not undoing or redoing her work, just updating it. Lyttle said he knew he “was standing on the shoulders of a giant.”

  An Expectation of Female Colleagues

  As for women helping women in the field, there has been a bit of indifference. This is not because women don’t want others to succeed; because the science has been so relatively egalitarian for so long, it may not seem as crucial that women support each other. Or perhaps the women drawn to the field are more focused on crystallography’s success than the success of individuals.

  Susan Lea, a microbiologist who studied structural biology for her PhD, said that she didn’t even think about putting particular effort into securing a female scientist role model because they were all around her. Judith Howard, one of Hodgkin’s students at Oxford, chose crystallography in part because there seemed to be plenty of women doing what she wanted to do, something Howard had never known before—even at her all-girls’ school, the chemistry teacher was male. It drove Hodgkin nuts that the media called only on her whenever they needed to talk to a “female scientist”: how “boring” to speak to just one person when there were plenty of options. However, nothing in life, including this, is clear-cut.

  Men Not Supporting Women

  More than once have men been given credit or taken credit for work they did not do or did not complete first. The New York Times misappropriated the vitamin B12’s structure solution to Alexander Todd at the University of Cambridge, and the Chemical Society at the University of Exeter asked Todd to speak first at the organization’s 1955 meeting. Hodgkin, whose Oxford team was the first to solve B12’s structure, thankfully was present and publicly explained the true order of credit due.

  Think of one of the biggest controversies in science: who figured out DNA’s structure first. Francis Crick and James Watson are widely understood to be the discoverers. Rosalind Franklin is hardly known at all, but when she is mentioned, she is discussed as the X-ray crystallographer who played a supporting role in their work. That may not be the complete story. After earning her doctorate in chemistry at Cambridge University, Franklin spent three years learning X-ray diffraction techniques at a lab in Paris. She then returned to England to be a research associate in a lab. She led one of two groups researching DNA. Maurice Wilkins was the leader of the other group. He was out of the office when Franklin started working in the lab, and when he returned, he assumed she was an assistant, not his equal. The university did consider women of lesser importance than men, even in small matters. The university dining rooms as well as the after-hours breaks at the pubs were men only. Wilkins’s incorrect perspective may have cost Franklin more than some social meals and happy hours; she came very close to solving the DNA structure, but Crick and Watson’s work was printed before hers in part because she wasn’t seen as deserving fair treatment.

  Women Being the Odd Ones Out

  Hodgkin’s first chemistry class in school was made up of nearly all boys—except for her and one other girl, Norah Pusey. Pusey did better than Hodgkin in chemistry, yet she left school for a college that taught her how to care for the home, essentially, making her a housewife, which was common at the time. She wrote to Hodgkin that she hated her new school and was envious of Hodgkin sticking with chemistry, which they both loved. Still, Pusey had made the decision to leave. Ultimately, she just didn’t think she could have made a living as a scientist. Better to do the “woman’s work” that she was expected to do. In the face of society telling her what opportunities she should expect and that she wasn’t capable at anything else, Pusey couldn’t believe what her high grades were actually telling her.

  She was far from the only woman who felt this way. Molly Crowfoot expressed concern to the teacher of two of her other daughters that Dorothy wouldn’t get into college. The woman assured Molly that Dorothy would because Dorothy wanted to study science and so few girls did so. The university would find her a novelty.

  This perception continues today. One science historian said that science businesses continue to want more women in their ranks because there simply aren’t enough there already. The International Union of Crystallography’s online list of scientists is 90 percent male. Its Ewald Prize has had one female recipient since 1987.

  A STABLE AND VAST NETWORK: INSPIRATIONS AND CONTEMPORARIES

  In 1971, at a meeting of biomedical researchers, women were invited to an evening cocktail hour to discuss the difficulties they faced as women in the male-dominated sciences. These challenges included job discrimination, not being selected for a job because of gender; receiving lower pay than men doing similar work; and being ostracized or ignored at work because their male colleagues didn’t think they belonged there. Twenty-seven women showed up to the cocktail hour. The conversation they had did not end that night. They kept the conversation going and founded the Association for Women in Science. This organization still works to make sure women and men are treated equally while working in science, math, and technology.

  Hodgkin didn’t have such an organization for most of her life and career, but she was part of an informal network of women scientists. She didn’t care for the term “role model,” but there were several women who inspired her. Some she worked alongside; some she never knew, but together they form a powerhouse of related visionaries. They all played a role—with or without her knowledge, directly or indirectly— in her success.

  Margery Fry (1874–1958)

  Dorothy Hodgkin’s and Margery Fry’s circles overlapped before they met. Fry’s sister ran the school two of Hodgkin’s sisters attended. Soon after, Hodgkin met Fry at Somerville College, a women’s school that was part of Oxford University. Hodgkin was a student, and Fry was the principal. They would become friends and remain inspirations for each other until Fry’s death.

  Throughout her life, Fry demonstrated her impressive intelligence and leadership skills. She studied math at Somerville and was the school’s librarian, in addition to being its principal. For her service, today one of the campus buildings is known as Margery Fry House. She held many top roles outside of academia as well. She served on the board of governors of the BBC. In 1921, she was appointed a magistrate; she was one of the first female magistrates. As a layperson, meaning in this case a citizen without legal qualifications, she helped make decisions in court cases.

  In this role, she focused on her lifetime passion: prison reform and the abolishment of the death penalty. Fry was born into a Quaker family and found her life’s purpose by following that faith-based community’s tenets of pacifism and social justice. By the time she became a magistrate, she’d already been secretary of a penal-reform organization. After her appointment, she was named education advisor to a women’s prison in London. Governments eventually took notice of her international lobbying efforts. For example, in 1963, New Zealand was the first country to fund a crime victims compensation program. Fry felt that such victims were owed something just as sufferers of accidents on the road or at work were.

  Though Hodgkin was dedicated to her work in the lab, she was just as much a member of the world. Her admiration of Fry is part of what encouraged her own peace and social reform work.

  They were also important to each other as part of the same network of intellectuals and revolutionaries who also happened to be women. For example, when William Bragg invited Hodgkin to photograph insulin crystals at the Royal Institution in London, she stayed with Fry. Also staying there was young Pamela Nicolson, daughter of mathematician Dorothy Wrinch, who was also Fry’s contemporary.

  At a time when women weren’t supposed to go t
o college and have careers, Dorothy Maud Wrinch was ahead of the curve, standing up for her research even when it was criticized.

  Dorothy Wrinch (1894–1976)

  Dorothy Wrinch’s and Dorothy Hodgkin’s life stories share similarities. For instance, Dorothy Wrinch was a British citizen born abroad; her father was an engineer stationed in Argentina. She too studied in England and was the only woman in her math class. She became the first woman to lecture in math at Oxford University. Wrinch also wrote and published several papers and books—192 in all.

  She earned her master’s degree in mathematics in 1920 and began studying for her PhD in the same field, but by the 1930s, she’d switched to molecular biology and started addressing biological problems with math.

  Her work focused on proteins, as Hodgkin’s did, and she put forth a new model of proteins’ structure. Her model was considered controversial because she stepped into a contentious issue with an unpopular view, and people took notice: in 1937 she went on a lecture tour in the United States, and the New York Times covered her talk at the American Philosophical Society in 1940.

  Linus Pauling disagreed loudly with Wrinch’s premise. This led to a public argument between the two in the Journal of the American Chemical Society. Some British X-ray crystallographers also attacked Wrinch, saying that despite her claims, X-ray data did not support her model. Wrinch eventually proved the cyclol bond that had caused so much hostility among her colleagues by using X-rays and the Fourier equation. She went on to spend more than twenty years focused on the importance of proteins in biology.

  Max Perutz (1914–2002)