Showing posts with label crystallography. Show all posts
Showing posts with label crystallography. Show all posts

Friday, January 24, 2025

Dorothy Crowfoot Hodgkin, chemist, crystallographer, Nobel laureate, mother, arthritis patient, peace and disarmament activist

Dorothy Crowfoot Hodgkin, linocut print, 11" x 14", by Ele Willoughby, 2025
Dorothy Crowfoot Hodgkin, linocut print, 11" x 14", by Ele Willoughby, 2025

The next prompt for PrinterSolstice is cobalt, an element animals including humans require for their metabolism, in the form of vitamin B12. So I made the portrait of English chemist and x-ray crystallographer Dorothy Mary Crowfoot Hodgkin (née Crowfoot, 1910-1994) won the Nobel Prize in chemistry for her models of biomolecules like penicillin, vitamin B12 and insulin, which were essential to structural biology.

The eldest of four daughters of English parents who were in the colonial administration of North Africa and the Middle East, and later, archeologists, Dorothy was born in Cairo, Egypt. The family escaped the heat of the summers by returning to England. When Dorothy was 4, her mother left her and her sisters Joan (2) and Elizabeth (7 months) with her Crowfoot grandparents near Worthing and returned to her husband and life in Egypt. The girls grew up with grandparents in England with parental support from afar. Dorothy became interested in chemistry as early as 4 and interested in crystals by age 10; "captured for life by chemistry and crystals," she later wrote. Her mother, a proficient botanist, encouraged her interests. She found a dark rock when visiting her parents in north Africa and asked a family friend, soil scientist A.F. Joseph if she could analyse it; he gave her a surveyor's box of reagents and minerals to encourage her.  She and her sisters would use a portable mineral kit to analyse pebbles they found in the stream.  During WWI, Dorothy lost four uncles on her mother's side influencing her to become an ardent supporter of the League of Nation and later a peace and disarmament activist. Her parents moved to Sudan where her father was in charge of eduction and archeology until 1926. In 1921, she entered Sir John Leman Grammar School, one of two girls allowed to study chemistry rather than domestic science usually assigned to girls.  She had one extended trip to spend time with her parents in Khartoum when she was 13.  A distant cousin who was a chemist, Charles Harrington (later Sir Charles) recommended D.S. Parsons' 'Fundamentals of Biochemistry' to her at age 14. She set up a a small lab in her attic, using chemicals she got from the local pharmacist. On her 16th birthday her mother gave her W.H. Bragg's 'Concerning the Nature of Things' about x-ray crystallography, which used the scatter pattern of x-rays through crystals at different angles, recorded on photographic plates to image crystals and use mathematics to then deduce their structure from these patterns. As Latin, required for entry to Oxford, was not on her school curriculum, the headmaster personally tutored her so she was able to pass the entrance exam. 

Post-WWI her parents eventually returned to their habit of summering in England to spend time with their children and escape the heat while working abroad. After retiring from the Sudan Civil Service in 1926, her father took job as Director of the British School of Archeology in Jerusalem and her parents lived there until 1935.

Dorothy joined her parents at the archeological site Jerash (present day Jordan) and documented patterns of mosaics of several 5th to 6th century Byzantine era churches, taking a year to finish her drawing just as she entered Oxford to study chemistry. There she also performed chemical analyses of glass tesserae from these sites. Her precise and meticulous drawings are now housed at Yale. She so enjoyed field archeology she considered switching her field of study. Her attention to detail in documenting patterns would later serve her well as a chemist. She graduated Oxford with a first class degree in chemistry in 1932.

She entered the PhD programme at Cambridge later that year studying with John Desmond Bernal and became interested in the use of x-ray crystallography to study the structure of proteins. She worked with Bernal on the first application of the method to image a biomolecule, pepsin. Previously, the method had only been used for inorganic crystals. Bernal believed in equal opportunities for women in chemistry and helped make x-ray crystallography one of the few fields with significant representation from women scientists. He followed in the example of William Bragg himself, who had 11 women amongst his 18 students. In 1933 she was awarded a research fellowship at Somerville College and returned to Oxford in 1934  to teach with her own lab equipment. She missed the day Bernal made the first photo of an x-ray of a protein crystal for health reasons. She was only 24 when she began experiencing pain in her hand which was diagnosed as chronic rheumatoid arthritis. She went to a clinic in Bruton for thermal baths and gold treatments before returning to work. The disease caused her hands to swell and become distorted; she had to add a special lever to the allow her to continue to use the main switch on the x-ray equipment. The disease is progressive and caused increasingly debilitating pain, problems and deformities in her hands and feet. She was appointed the college's first fellow and tutor in chemistry in 1936, a roll she held until 1977. She earned her PhD in 1937 on the x-ray crystallography and chemistry of sterols. In 1945 with C.H. Carlisle, she published the first structure of a steroid, chloresterol iodide. From 1941 through 45, she worked with colleagues including Barbara Low, on solving the structure of penicillin. She made her calculations manually with a set of specially printed paper strips and with her team plotted 108,00 points in the molecule to make two-dimensional contours of electron densities. With help from her sister, she drew the contour sheets on perspex so these 2D slices could be stacked to visualize the molecule in three dimensions. Only then could she make the traditional ball and stick model (like I have shown in my portrait); she surrounded hers with 2D contour plots of electron density. Country to scientific opinion, they found that penicillin contained a β-lactam ring. She was doing all this intense work while Thomas was teaching in Newcastle; she had to send him a telegram to alert him the arrival of their second child was imminent. The research was characterized as a wartime secret. She sent Thomas a postcard, 'Think we really have found out something for certain about P. Am extremely cheerful.' They completed the work on VE day in 1945. She became a Fellow of the Royal Society in 1947. They published their penicillin results in 1949; she bowed to social pressure at this point and added Hodgkin to her name, though she had up to this point published as Dorothy Crowfoot.

In 1948, Merck discovered vitamin B12, one of the most complex vitamins then known, and Hodgkin created some new crystals. Merck only published its refractive indices. When she realized it contained cobalt, she knew the almost completely unknown structure could be established with x-ray crystallography, but its size and largely unidentified atomic components would make it a challenge. Since the crystals were pleochroic, that is, they displayed different colours at different angles, she deduced the presence of a ring structure, confirmed by x-ray crystallography. Her 1954 published study was described by Nobel Laureate Lawrence Bragg as being as significant as "breaking the sound barrier." She published the final structure in 1955 and 56. 

In 1953, she, Sydney Brenner, Jack Dunitz, Leslie Orgel, and Beryl Oughton (later Rimmer), were the first people to drive from Oxford to Cambridge in two cars to see the model of the double helix of DNA built by James Watson and Francis Crick, informed by x-ray crystallography by Maurice Wilkins and Rosalind Franklin and their student Gosling. 

In 1957 the Royal Society awarded her the Royal Medal and she became a reader at Oxford, gaining a full, modern laboratory in 1958. She was appointed the Royal Society's Wolfs Research Professor in 1960 through 1970 which provided salary, research expenses and assistance and she was a fellow of Wolfson College, Oxford from 1977 to 1983. 

Insulin, illustrated by Dorothy Crowfoot Hodgkin
Insulin, illustrated by Dorothy Crowfoot Hodgkin. This drawing was presented to crystallographer Dr. Helen Megan who was organizing the Festival Pattern Group in Britain in 1951. Hodgkin refused a fee or to copyright an image found in nature. Megaw organized an exhibit of the wonders of scientific patterns applied in design as part of the Festival of Britain. I decided life is too short to try and make a relief print of a molecule this complex!

One of her most important and celebrated studies was the longest lasting. She first received a sample of insulin in 1934. The size and complexity of the molecule was too great to explore with x-ray crystallography at that time, but the importance of the hormone captured her imagination. She had paused this research to work on the structure of penicillin, which contains 17 atoms, and vitamin B12, which contains 181 atoms, but returned to it later. By 1969, 35 years later, she was finally able to work with an international team of young scientists to reveal the structure of insulin. Insulin contains 788 atoms! It's hard to overstate the size of the task and the sheer number of calculations involved. This work was instrumental in our ability to mass-produce insulin and treat diabetes and also to allow scientists to alter the structure of the molecule to create even better drug options. She remained active in collaborating on insulin production and drug development to better treat diabetes. 

Sample of insulin wallpaper design made for the Festival of Britain
Sample of insulin wallpaper design made for the Festival of Britain. This simplified and stylized insulin design inspired the blouse she's wearing in my portrait.

Soft-spoken and gentle but determined and hardworking, Hodgkin inspired her students, whom she encouraged to address her simply as Dorothy. Her most famous student moved on from chemistry to politics; conservative UK PM Margaret Thatcher (née Roberts), hung Hodgkin's portrait in her office, out of respect for her former tutor, the livelong Labour supporter, sometime Communist Party of Britain member and pacifist Hodgkin. Hodgkin's politics were greatly influenced by her mentor Bernal, an open and vocal communist and supporter of the Soviet regime until it invaded Hungary in 1956. She always called him "Sage" and they briefly had a relationship (unconventionally, Bernal had an open marriage) before she met Thomas Hodgkin. Thomas was teaching adult education classes in northern English mining and industrial communities, after resigning from the Colonial Office. Intermittently a member of the Communist Party, he later wrote several works on African politics and history and lectured at Balliol College, Oxford. The two married in 1937 and had three children, Luke (1938-2020), Elizabeth (1941), and Toby (1946). Thomas spent a much time in west Africa, supporting and chronicling emerging postcolonial states. A lifelong advocate for peace, Dorothy campaigned against nuclear arms and the Vietnam war. Because of Dorothy's political activities and her husband's communist party membership she was banned from entering the US in 1953, and subsequently not allowed in without CIA waiver. 

She was in Ghana, where her husband was an advisor to president in 1964 when she learned she had been awarded the Nobel Prize for Chemistry her work on the structure of biomolecules. She served as President of the International Union of Crystallography, an organization she helped found, from 1972 to 1975 and worked to foster international collaboration. She worked to include Chinese and Soviet scientists through the Cold War. In 1976 she won the prestigious Copley Medal, the first woman to do so (the second wasn't until Jocelyn Bell Burnell in 2021). Concerned about social inequities and preventing war and in 1976 she became the longest-serving president of the international Pugwash Conference on Science and World Affairs, which brings scientists and public figures to work together to reduce the risk of armed conflict and seek solutions to global security threats. She stepped down in 1988 after the signing of the Intermediate-Range Nuclear Forces Treaty ban on short and long-range nuclear weapons. She accepted the Lenin Peace Prize from the Soviet government in 1987 for her peace and disarmament work. Fellow chemist, peace activist and Nobel laureate Linus Pauling had recommended her for the award.

In later years she spent a great deal of time in a wheelchair because of the progress of the rheumatoid arthritis, but she was able to remain an active scientist. She skipped the 1987 Congress of the International Union of Crystallography in Australia, but attended the 1993 Congress in Beijing. She died by stroke in 1994 in her husband's village of Ilmington. 

The Royal Society now awards the Dorothy Hodgkin Award in her honour to outstanding early career scientists requiring flexible work due to caring or health reasons. The Council offices in Hackney, university buildings at the universities of York, Bristol and Keele and the science block at her old school Sir John Leman High School are named in her honour. Oxford International Women's Festival presents the annual Dorothy Hodgkin Memorial Lecture in her honour.

Her work helped in the rapid production of penicillin, considered a miracle drug at the time, mapping vitamin B12 helped the fight against pernicious anemia and her structure of insulin greatly improved our ability to treat diabetes. She left her mark on science and society both.

References,

All or Nothing,  Back From the Dead exhibit website from The Museum of the History of Science, 2021

Alman, Margaret. Art in the Atoms: Chemist Dorothy Crowfoot Hodgkin, blog post, February 3, 2010.

Cole, Rupert. Happy Birthday Dorothy Hodgkin. Science Museum blog. May 11, 2018

Dorothy Crowfoot Hodgkin, Nobel Prize website, accessed January, 2025

Dorothy Hodgkin, Wikipedia, accessed January, 2024

Hodgkin, Dorothy Mary Crowfoot, Jennifer Kamper, June Lindsey, Maureen F. Mackay, Jenny Pickworth, John H. Robertson, Clara Brink Shoemaker, J. G. White, R. J. Prosen and Kenneth N. Trueblood. “The structure of vitamin B12. I. An outline of the crystallographic investigation of vitamin B12.” Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences 242 (1957): 228 - 263.



Thursday, February 23, 2023

Kathleen Lonsdale, crystallographer, pacifist and prison reformer

 

Kathleen Lonsdale linocut print by Ele Willoughby
Kathleen Lonsdale, 11" x 14" linocut print on Japanese kozo by Ele Willoughby, 2023

I chose Kathleen Lonsdale DBE FRS (née Yardley, 1903-1971) for the #printerSolstice prompt shape because she solved a longstanding chemistry conundrum of the shape of benzene & her drawing of electron density for hexachlorobenzene (green) & model of hexamethylbenzene explore shape in different forms. 

Going to Holloway prison was the single most formative experience for Kathleen Lonsdale’s scientific career and it gave her the ability to speak to anyone. Her husband said, “Before prison it might have bothered her to go to Buckingham Palace. Afterwards, Holloway or Buckingham Palace were all the same.” Born the tenth child of a poor family in Ireland, with four brothers who died in infancy, pacifist, prison reformer and physicist Dame Kathleen Lonsdale DBE FRS (née Yardley, 1903-1971) served time, as she was unwilling to compromise her beliefs. She was also a trail blazing crystallographer who solved a conundrum which had plagued chemists for decades: the shape of the benzene ring, proving it was flat using x-ray diffraction on hexamethylbenzene in 1929. She was the first to employ Fourier spectral methods and used them to solve the structure of hexachlorobenzene in 1931. In 1945 she was one of the first two women elected Fellow of the Royal Society and was the first woman in several roles including: tenured professor at University College London, president of the International Union of Crystallography and president of the British Association for the Advancement of Science.

Her father, a soldier and then a postmaster Harry Yardley and her mother, a strict fundamentalist Baptist of Scottish descent Jessie Cameron did not have a happy marriage. Between the unrest in Ireland and her father’s alcoholism, her mother decided to divorce and move the children to Seven Kinds, Essex, England when Kathleen was five. She won a scholarship to the Ilford County High School for Girls but had to go to the boys’ school in her final two years as the girls’ school did not offer mathematics and science. During WWI her home was on the Zeppelin route; she did homework by candlelight during air raids and first developed her opposition to war. Anxious to get to university as soon as possible she went to the Bedford College for Women in London on a county scholarship. After her first year she won a university scholarship and switched from mathematics to physics, against all advice (especially that of her old headmistress who told her she would never distinguish herself in physics). She graduated in physics with the highest score ever for a London University, with a BSc in 1922, which brought her to the attention of physics Nobel laureate William Henry Bragg, one of her examiners.

Bragg offered her a spot on his team at University College (and then the Royal Institution), and a grant of a £180 a year! She lived at home and contributed to family expenses, gaining her MSc from University College London in 1924. She worked with Bragg until she married in 1927 and followed her husband, research chemist Thomas Lonsdale to Leeds, where he had been offered a job at the Silk Research Association. Shortly after her marriage, she applied for an 1851 Exhibition Fellowship which Bragg expected she would win, as several of his other (all male) students had done. Not only did they turn her down for the award, they wrote they “would be breaking the spirit of the regulations in awarding an exhibition to a married woman.” Luckily Bedford College offered her a research grant and she continued to correspond with Bragg. She worked part-time as a physics demonstrator and doing lab work in Leeds. It was here that she was given crystals of hexamethylbenzene, the first important structure she solved. Debate had been raging between organic chemists and crystallographers whether benzene was flat or  had a zigzag shape like cyclohexane, but benzene itself was a challenge to crystallize. Lonsdale had the insight that she could instead look at the benzene within hexamethylbenzene and in the process of solving its form, she proved that the benzene ring (which it contained) was flat. She followed this with solving the structure of hexachlorbenzene; this was important as she was the first to investigate an organic compound with Fourier analysis. She had cleverly found a project she could do with calculations rather than lab work while she focused on starting their family. She also developed popular crystallographic reference tables with W.T. Astbury. She considered giving up science, but Thomas supported her research told her he “had not married to get a free housekeeper.” He encouraged her to continue in research. When they had their first daughter in 1929, Bragg convinced the Royal Institution to grant her £50 to employ some childcare  so she could work on calculations. Then they moved back to London for Thomas’ new job, and had a second daughter in 1931. Bragg, anxious to have her back, was able to find a further £200 to assist her at home so she could  return to work in 1931. They had their son in 1934. She earned her doctorate from the University of London in 1936 while working at the Royal Institution, where she stayed for 15 years. She worked with Bragg until his death in 1942, then with Sir Henry Dale, as a Dewar Fellow from 1944 through 1946.


She was raised a Baptist, but in 1935, she and her husband, both committed pacifists, became Quakers. She became a Sponsor of the UK Peace Pledge Union, which meant she signed the pledge "War is a crime against humanity. I renounce war, and am therefore determined not to support any kind of war. I am also determined to work for the removal of all causes of war.” They turned the top floor of their house into a flat where they welcomed refugees from Germany. When she was required to register for civil defence duties during WWII she refused to do so and refused to pay the small fine for not registering. She believed there should be an exemption for conscientious objection. She was sentenced to serve a month in Holloway prison, where the grim conditions lead to a life-long commitment to prison reform. While she was imprisoned, she found the clothing unclean, medical exam sketchy and she collapsed under her workload, scrubbing and cleaning; only then did they lighten her workload. Sir Henry Dale requested that she be given access to papers and instruments and she was allowed to work in her cell in the evenings.  Her colleagues worried she would be bored; she was in fact absorbed, talking to fellow prisoners about their lives and crimes. Her second fine for refusing to register for civil defence was paid anonymously, much to her chagrin; she would have rather stood on her principles and serve another prison term. She contributed to a pamphlet on Prison for Women about her experiences in Holloway and the need for prison reform.

In 1945 Lonsdale and Marjory Stephenson were the first women elected Fellows of the Royal Society. Then she finally got a permanent position. In 1946 she was appointed Reader in Crystallography and then Professor of Chemistry and Head of the Department of Crystallography at the University College London in 1949, finally beginning to teach and run her own research group, mentoring future crystallographers. She was their first tenured female professor. She researched the use of x-ray imaging at different temperatures and the structure and texture of crystals. She worked on the synthesis of diamonds. She won the Royal Society’s Davy Medal for significant discoveries in chemistry in 1957. Later she worked on solid state reactions, pharmacology and structure of methonium compounds and stones and minerals produced by the human body like kidney stones. She became an emeritus professor after 1968. Nobel laureate Dorothy Hodgkin wrote, "There is a sense in which she appeared to own the whole of crystallography in her time.


In 1953 she delivered the keynote Swathmore Lecture at the Yearly Meeting of British Quakers, “Removing the Causes of War”. She wrote about peaceful dialogue was appointed the first secretary of Churches' Council of Healing by the Archbishop of Canterbury. 


When Thomas retired at 60, they moved to Brexill-on-Sea; this meant 5 hours a day commute for Kathleen, but she felt it worthwhile though she was tired. Thomas helped with her tremendous amount of correspondence about peace and prison reform, and would bring her dinner in bed as soon as she got home. She was someone who never stopped working, even when she became ill and was hospitalized. She died in hospital 1971 from anaplastic cancer, at age 68, the day after Thomas' 70th birthday.

References

Kathleen Lonsdale, Wikipedia, accessed February, 2023

Hodgkin, Dorothy M.C., Kathleen Lonsdale, 28 January 1903 - 1 April 1971, Biographical Memoirs of Fellows of the Royal Society, Volume 21, Issue 21, November 1975

Melinda Baldwin, The Royal Society’s first woman physicist, Physics Today, 25 January, 2018. DOI: 10.1063/PT.6.4.20180125a

One crystal model of hexamethyl benzene, Science Museum Group, Object Number: 1993-421/4/11, Gift of University College London, in memory of Dame Kathleen Lonsdale 

Wednesday, October 7, 2020

Rosalind Franklin, revealing the the double helix of DNA, the structures in carbon materials and the shapes of viruses

Roaslind Franklin, linocut, 11" x 14", by Ele Willoughby 2020

 

Rosalind Elsie Franklin (25 July 1920 – 16 April 1958), the English chemist and x-ray crystallographer whose x-ray diffraction images were instrumental to discovering the double-helix structure of DNA, has been on my to do list for scientist portraits for years and I've finally got around to it. I think it's the messiness and tragedy of her story that made it a challenge. The version of Franklin which is best known by the general public, is the version presented by the Nobel laureate once described by E. O. Wilson as "the most unpleasant human being I had ever met" James Watson, in his biography The Double Helix, published in 1968. Not only does he call her patronizingly Rosy, he presents her as a dowdy data-hoarding scold who "had to go or be put in her place". Ironically, his biography hurt his own reputation (though he's quite skilled at hurting his reputation more recently, what with the repeated pro-eugenics, racist, homophobic and sexist comments). Watson confessed, “Rosy, of course, did not directly give us her data. For that matter, no one at King's realized they were in our hands.” Strangely, after the publication of their DNA structure papers, Watson and Franklin were on friendly terms, exchanged letters and he even once offered her a lift across the US. His version of her as the villain emerged years after her death, when he wrote the book; some (like Franklin's biographer Maddox) suggest guilty feelings about the irregular way her data was accessed and insufficiently cited are the explanation. Before the book was published, Francis Crick, Maurice Wilkins, Linus Pauling, Max Perutz and Rosalind's brother Colin all protested angrily at her portrayal (as well, often, as the portrayal of themselves and other scientists), especially as she could not defend herself. This forced Watson to add an epilogue praising her as a scientist and claiming he hadn't sufficiently appreciated the experience of women in science at that time. Wilkins wrote to Harvard University Press that the book remained disgraceful and they dropped it; it was published instead by Athenaeum Press, becoming a bestseller.

There's a joke amongst scientists that goes, "What did Watson and Crick discover?" "Rosalind Franklin's notes." And while it's important that her contributions are now recognized posthumously, there's more to her story and to the story of DNA research. Ironically, the famous Photo 51 produced by Franklin's graduate student Raymond Gosling, which Maurice Wilkins quietly shared with Watson and Crick and cemented their thinking about molecular structure, is a photo that Franklin had previously presented at a seminar attended by Watson (where he failed to notice it, presumably thinking patronizing thoughts about "Rosy"). Watson, Crick and Wilkins were awarded Nobel prizes in 1962, after her death.  Though this was prior to the institution of the informal rule against awarding posthumous Nobels, Franklin was not nominated. Before her life was cut tragically short by ovarian cancer, both prior to and after her DNA research, Franklin also made invaluable contributions across disciplines of physics, chemistry and biology, working to determining the structure of RNA, viruses, coal and graphite. Even aside from her role in determining the structure of DNA, her research was a great benefit to society. I wanted to make sure my portrait represented all of this.

But first, this is a wonderful comic by the one and only Kate Beaton:

 

by Kate Beaton
by Kate Beaton from Hark, A Vagrant

Rosalind was born in 1920, the second of five children born to a liberal, affluent and influential London Jewish family. Her father was a merchant banker and his uncle had been Home Secretary, the first practising Jew to serve in the British Cabinet. Her father taught electricity, magnetism and history of the Great War, at the Working Men's College and eventually became Vice Principal. Her family helped settle Jewish refugees fleeing the Nazis, especially children from the Kindertransport. They took two of the children into their home. Rosalind attended St. Paul's school, a leading girls' private school, one of few girls' schools which taught physics and chemistry. She excelled at sciences, languages and sports and won a scholarship for university. Her father asked her to donate the funds to a refugee student. She studied chemistry at Newnham College, Cambridge, completing her undergraduate studies in 1941. Due to the sexist attitudes of the day, women were not granted full degrees, but "degrees titular," until 1948 (when previous women's degrees were retroactively awarded). In her last year at Cambridge she met a French refugee and former student of Marie Skłodowska-Curie, Adrienne Weill; this friendship was an opportunity to practice her French and became important in her career.

She began a PhD project on the polymerisation of acetaldehyde and formic acid under the supervision of Ronald Norrish, Professor of Physical Chemistry at Cambridge and later a Nobel laureate. It was not a fruitful collaboration. His own biographer described Norrish as "obstinate and almost perverse in argument, overbearing and sensitive to criticism" and Franklin grew to despise him and resigned. She gladly took an opportunity to transfer to the British Coal Utilisation Research Association (BCURA) at Kingston-upon-Thames. She began focusing on the porosity and density of coal, to learn how to increase the efficiency of the widely used fossil fuel resource. Her work also had important implications for the effectiveness of the activated-charcoal filters in Second World War gas masks, issued to the entire British populace in case of gas attack. In working to accurately determine the porosity of coal, she made what was likely the first demonstration that coal acts as a molecular sieve (letting helium molecules through but not larger hexane and benzene). This property is still important to industry today.

She completed her doctorate on the structure of carbon materials in 1945 (and once again, as a woman, had to wait to be awarded her full degree until 1948). Her friend Adrienne Weill suggested she attend a Royal Institution meeting in London where she might meet Marcel Mathieu and Jacques Méring. At this conference her interest was sparked in x-ray diffraction and she met the great crystallographer J.D. Bernal (with whom she would later work). Impressed with her paper Méring offered her a researcher post in Paris to continue her work on carbons for four happy years. Méring was a x-ray crystallographer, who employed the way substances diffracted x-rays to deduce their structure and he taught her how to apply this method. By 1950 she had published a paper in Nature about the structure of carbon, and by the following year had learned that as carbon in the form of coal burns, it can form one of two structures: graphitizing and non-graphitizing (terms she coined). In my portrait, the pattern on her jacket is based on her own publication of the structure of non-graphitizing carbon. She showed these two structures explained the difference between the two possible products of burning coal: cokes and chars, and how they burn. This research had important industrial applications. She continued to write papers about the structure of carbon until she died. 

She returned to England in 1950 to work with John Randall, head of the Biophysics Research Unit at King’s College, on a three-year Turner-Newall Fellowship. She planned to look at protein structure but he suggested she work on DNA, as Maurice Wilkins was doing. Randall did not clarify whether Franklin or Wilkins would lead this research, which set their relationship off on the wrong foot. Randall reassigned Wilkin's graduate student Raymond Gosling as her assistant; this surely also did not help things between them. Franklin refined and adjusted the fine-focus X-ray tube and microcamera ordered by Wilkins, improved upon his technique by manipulating the critical hydration of her specimens and employing all her physical chemistry expertise. Wilkins inquired about this and felt her reply was superior. Her directness and enjoyment of a good debate were a bad match for his shyness and distaste for arguments, and their personalities clashed badly.

As early as November 1951, Franklin presented their data at King's College London and noted,

"The results suggest a helical structure (which must be very closely packed) containing 2, 3 or 4 co‐axial nucleic acid chains per helical unit, and having the phosphate groups near the outside."

Franklin and Gosling found there were two forms of DNA: long and thin when wet (dubbed B-DNA) and short and fat when dry (dubbed A-DNA). Because of their conflicting personalities, Randall divided the labour so Franklin and Gosling studied the A form and Wilkins the B. They produced beautiful images of DNA during this time, including Gosling's famous Photo 51 (represented in blue in my portrait). By 1951, the King's researchers all believed B-DNA was a helix, but Franklin felt the evidence for A-DNA was still conflicting. Through painstaking work, by January 1953, Franklin reconciled the conflicting data, concluding both forms had two helices. She drafted three papers, and two noted the double helical DNA backbone. She had also decided to leave the unpleasant atmosphere at King's and move to Birkberk College. Randall insisted that the DNA research stay at King's and Gosling would be reassigned back to Wilkins.

Meanwhile in Cambridge, James Watson and Francis Crick were simultaneously working on the problem and had seen a preprint of Linus Pauling's incorrect proposal for DNA. They came to King's to urge collaboration to win the race before Pauling discovered his error. Thanks to Franklin's identification of the nature of the symmetry of the DNA crystals (that is, its space group), Crick understood that DNA strands were antiparallel (and that both Pauling's model and Watson and Crick's previous model were incorrect). Unable to find Wilkins they spoke with Franklin who was unimpressed by Watson's implication she could not interpret her own data; they argued. Wilkins arrived, commiserated with them, and showed Watson Franklin's work and Gosling's DNA image.  From Wilkins' perspective, Franklin was leaving, and Gosling was now his student; but it seems he did not let Franklin know he had done this. In February 1953, Watson and Crick began working on a molecular model of B-DNA, something Franklin felt was premature, with much of the data based on work at King's. Crick got access to many of Franklin's crystallographic calculations when his advisor Max Perutz gave him a report written for a Medical Research Council biophysics committee visit to King's in December 1952. Though not explicitly marked confidential there was an expectation that such a report would not be shared and Perutz later defended this action with inexperience with administrative matters. Franklin's A-DNA paper was submitted 6 March 1953, one day before Crick and Watson had completed their model on B-DNA. She had not seen Watson and Crick's work when she submitted her paper (though they had of course benefited from seeing her, Gosling and Wilkin's work). Her laboratory notebooks reveal that she had already Franklin noted that ‘an infinite variety of nucleotide sequences would be possible to explain the biological specificity of DNA’ all on her own. Franklin got to see the model built by Watson and Crick on April 10 and apparently commented, "It's very pretty, but how are they going to prove it?" Her philosophy as an experimentalist was to be able to rigourously prove a model correct before publishing. Franklin did modify her paper while in press, after seeing the others' work to acknowledge their work. A trio of DNA papers were published as 25 April 1953 Nature articles. Watson and Crick's paper only acknowledged "having been stimulated by a general knowledge of" Franklin and Wilkins' "unpublished" contribution. Due to agreements between the directors of the King's and Cambridge labs, Wilkins and Franklin published the two other DNA articles with x-ray diffraction data supporting Watson and Crick's model (rather than presenting them as the data which underpinned the model). Watson and Crick invited Wilkins to be a co-author but he declined because he had not help build the model. He later lamented that they can not discussed authorship more thoroughly. 

It may have been less than obvious to Watson and Crick how to cite materials they used, including Photo 51 and the MRC report, but it is something that they could have been done and ethically, many argue that they should have done. Likewise, Watson and Crick were aware of Franklin and Gosling's paper (which included Photo 51), submitted before she saw their work, but they merely noted that their model was not inconsistent.  Any mention they made of Franklin is in combination with, and after naming Wilkins. There is a strong case to be made that Franklin's work was insufficiently credited, and its value and role in determining the structure of DNA has only be recognized posthumously. There's no evidence that Watson and Crick ever let Franklin know what they later acknowledged, that they could not have made their model without out her work, or that she felt insufficiently recognized in their publication. They remained friends during her life and continued to correspond about their respective research projects.

By mid-March, Franklin moved to the much less fancy but much more pleasant Birkberk College, having been recruited by physicist John Desmond Bernal. She was much more comfortable at the non-denominational Birkbeck than the Anglican King's. Though Bernal wanted her to move on from nucleic acid, she continued to mentor Gosling and aid him with the completion of his thesis. The two published the first evidence of the double helix in the A form of DNA in the 25 July issue of Nature. With funding from the Agricultural Research Council, she was able to start her own research group and begin working on RNA and the structure of the Tobacco Mosaic Virus (TMV), an RNA virus. In my portrait her brooch is a model of TMV. She published her first major TMV paper in 1955 in Nature, in opposition of prominent and powerful virologist Norman Pirie, who wrote her angry, condescending letters and refused to ever again supply her with virus samples to study. But her careful observational work was once again correct. With her grad student Kenneth Holmes she found the protein covering was molecules arranged in helices. Early in 1954, she happened to meet Aaron Klug on the stairs at work. She showed him her photo of the TMV and he wrote, it sealed his fate. Captivated, he sought permission to switch to virus research. They began a long and fruitful collaboration. She oversaw a group with her students, Aaron Klug and his student John Finch and the group published on TMV, cucumber virus 4, turnip yellow mosaic virus and other plant viruses. She had a student James Watt supported by the National Coal Board and continuing her longstanding research interest in carbon. With postdoc Donald Caspar she showed that the RNA was wound on the inner surface of the hollow TMV.  She had begun working on the structure of the Polio virus, receiving with Krug the large grant ever at Birkbeck. While traveling in the US in 1956, she noticed her stomach had swelled and she went to the doctor upon her return. They found two tumours. She had ovarian cancer. She continued working when not hospitalized or convalescing with family and friends (including Francis and Odile Crick, with whom she remained close). Her group produced seven papers in 1956 and six in 1957, despite the cancer. She  was promoted to Research Associate in Biophysics on the 25th of February. Tragically she was not able to proceed with the polio research as her health rapidly deteriorated. She was invited to display a large model of TMV in Brussels at Expo 58, the first major international fair after World War II; the fair opened the April 17, but she died April 16, 1958 of bronchopneumonia, secondary carcinomatosis, and ovarian cancer. It's possible that x-ray exposure played a role in the cancer. Science during the 1950s was far too laissez-faire about radiation shielding. The following year, Klug and Finch published the polio virus structure and dedicated the paper to her memory.

By 1962 the scientific community at large was convinced of the structure of DNA, and Watson, Crick and Wilkins were awarded the Nobel Prize in Physiology or Medicine. The rules preclude splitting the award more than 3 ways and Wilkins' inclusion was based not only on his role in discovery but his later work providing data to support the model. As Franklin foresaw, it took years of work to actually convincingly prove the "pretty" model. But, even Watson suggested that Wilkins and Franklin might instead have shared the Nobel in Chemistry. Franklin was never nominated, even though this predates their rule against posthumous prizes.

Also, her long-term collaborator on virus structure, Aaron Klug continued the work he began with Franklin, winning the 1982 Nobel Prize in Chemistry for his development of crystallographic electron microscopy and his structural elucidation of biologically important nucleic acid-protein complexes. Her staunchest defender, and beneficiary of her will, he spoke of her and her impact upon him in his acceptance speech.

Today, she has become one of the most widely recognized researchers in the history of science, with many awards, buildings, plaques and monuments in her honour, worldwide. Elucidating the structure of DNA has perhaps had the most impact on society at large, but her research in carbon and on viruses also has lasting significant impacts in science.  

References

Brenda Maddox,  'Rosalind Franklin, The Dark Lady of the DNA,' HarperCollins, 2002.

Brenda Maddox, The double helix and the 'wronged heroine'. Nature 421, 407–408 (2003). https://doi.org/10.1038/nature01399

Peter J. F. Harris and Irene Suarez-Martinez, 'Rosalind Franklin, Carbon Scientist', Carbon, vol. 171,  January 2021, pp. 289-293 https://doi.org/10.1016/j.carbon.2020.09.022 

'Rosalind Franklin was so much more than the ‘wronged heroine’ of DNA', editorial, Nature 583, 492 (2020)

'Rosalind Franklin,' Wikipedia, accessed October 2020.

Mathew Cobb, 'Sexism in science: did Watson and Crick really steal Rosalind Franklin’s data?' The Guardian, Tuesday 23 June, 2015. 

, Rosalind Franklin

 Dainton, Sir Frederick Sydney (1981). "Ronald George Wreyford Norrish, 9 November 1897 – 7 June 1978". Biographical Memoirs of Fellows of the Royal Society. 27: 379–424. doi:10.1098/rsbm.1981.0016. JSTOR 769878. S2CID 72584163

Wednesday, August 21, 2013

Quartz

quartz

This is an apt little linocut for your cabinet of curiosity; a quartz crystal complete with iridescent facets. I printed a variable edition of eight prints, 6.25" by 7.5" (16 cm by 18.8 cm) on Japanese kozo (or mulberry) paper, with chine collé (collaged fine Japanese paper) facets in iridescent pink origami paper. Each print is unique, with a different selection of iridescent facets. Depending on the angle at which you view the print, these facets can appear to include a shimmering range of blue through pink through yellow. The specimen is labelled 'Quartz' in a printed script, so you can begin a hand-printed mineral portrait collection.

Quartz linocuts

Wednesday, November 10, 2010

Snowflakes

large snowflake ornament

I thought I'd make some snowflake ornaments.

I hope this pretty thing helps me face my dreaded teleconference *shudder* today. Wish me luck!

Saturday, January 24, 2009

Dendrites

frost patterns

Dendrites, tree-like advance patterns of crystal growth, in stead of actual trees, are the view out my window this morning.

From the Greek δένδρον déndron, “tree”...

The beauty of physics is the underlining patterns.