10
INVENTIONS AND IMPROVEMENTS
It is very rare for the river of scientific discovery to run a straight and uncomplicated course. Short of flowing uphill, this river can do almost anything, mainly because it is fed by tributaries whose behaviour can be unruly and unpredictable. Some of those tributaries bring clarity, fresh ideas and new perspectives, like a mountain stream brimming with oxygen and vitality. Others are virtually lifeless, thick with the sediment of spent thought and ready to dump their burden at the first opportunity.
At risk of overstretching the metaphor, the history of DNA is a fine illustration of these principles. Phoebus Levene and Albrecht Kossel effectively killed off all life in their tributary, which then threatened to pollute the much broader waters downstream. Meanwhile, another tributary was gaining strength and transforming the landscape around it – but without showing any sign that it was destined to merge with a different stream which was meandering towards an understanding of the gene and its mysteries.
That second tributary was the discipline of X-ray crystallography. Everyone familiar with the climax of the saga of the double helix knows that this was the decisive technology which made it all happen. However, there is much more to the role of X-ray crystallography and its practitioners than that dramatic but brief episode. To skate over the twenty years of research that led there – as many authors have done – would be another kick in the teeth for several largely unsung heroes, without whom that final chapter would never have been written in a form that we would recognise. And as well as denying them their moments of glory, this would rob us of the chance to meet some of the most colourful characters in the cast.
With that preamble, we return to London on the threshold of the Roaring Twenties, and a once noble institution that was in urgent need of resuscitation.
Diffusion of knowledge
A cursory glance around the auditorium would have confirmed that this was something that William Bragg did supremely well. He had been invited to give the 1919 Christmas Lectures at the Royal Institution in London and had chosen the theme of ‘Sound’. Over six successive evenings, his topics ranged from ‘Sound and Music’ to ‘Sounds of Nature’, finishing with a subject that was still fresh in everyone’s memory. ‘Sounds of War’ featured the Bragg family’s interests in U-boat detection and artillery sound-ranging – while remaining within the limits of what the Official Secrets Act allowed him to talk about. Throughout, Bragg held his audience absolutely captivated. They sat silently around the steeply tiered lecture theatre, all ears and eyes focused on the man at its centre, then filed down to crowd excitedly around his demonstration table when invited to come and take a closer look at the experiments.
At the time, there were deepening concerns that German technology, now recovering from its post-war privations with the help of a massive injection of American cash, would regain its former might and surge ahead of Britain. However, anyone observing the Christmas Lectures would have felt huge optimism for the future of British science. In accordance with the directive of Michael Faraday, who had established the tradition in 1825, the lectures were tailored for a ‘Juvenile Auditory’, because the target audience was children. Bragg knew intuitively how to tune into those fresh young minds, and as far as the juveniles were concerned, his pitch was perfect.
That was William Bragg’s formal introduction to the Royal Institution. After the New Year break, he returned to University College London, where he had been appointed Professor of Physics in 1915. He found it just the same as it had been before Christmas: dull, unrewarding and strangling itself in the pompous politics in which universities revel.
In 1923, the top job came up at the Royal Institution. A furnished flat (in Mayfair, no less) was included and the salary was acceptable if unspectacular. Once upon a time, running the Royal Institution had been as prestigious as any scientific professorship in the land, but the place had fallen on hard times and was now a research backwater. Going there was an odd move for a Nobel laureate, but Bragg (by now Sir William) took the risk and accepted the post of director. This time, it was for keeps: the Institution was where he took up residence and spent the rest of his career, and where he died.
The Royal Institution had been conceived in London on 8 March 1799, by a group of the nation’s most eminent scientists. To demonstrate how small the world can be, they met in Sir Joseph Banks’s former house in Soho, where Robert Brown later popped nuclei out of plant cells; and their leader was Sir Henry Cavendish, whose name eventually graced the laboratory in Cambridge where Lawrence Bragg, Jim Watson, Francis Crick and the graceful twin spiral of DNA were destined to come together a century and a half later.
The new Institution took shape behind the elegant colonnades of No. 20 Albemarle Street in Mayfair and opened its doors for business in 1800. From the start, its mission was to break new ground and to educate, by ‘diffusing the knowledge and facilitating the general introduction of useful mechanical inventions and improvements; and teaching, by courses of philosophical lectures and experiments, the application of science to the common purposes of life.’
With Humphrey Davy as its first Professor of Chemistry, the Institution was launched straight into its golden age. In three heady months in 1808, Davy discovered one element after another by running an electric current through molten salts – sodium, potassium, boron, calcium and strontium, ending with barium to celebrate the New Year of 1809. Davy’s glory shone a flattering light on the Institution and on science in general. He became a celebrity who scaled the heights of society with the likes of William Wordsworth and Sir Walter Scott (and climbed Helvellyn with both of them in 1806).
Davy’s legacy included the young man whom he appointed as assistant and note-taker after his own eyes were damaged in a laboratory explosion in 1812. Michael Faraday was already known for his experiments with ‘laughing gas’ (nitrous oxide), introduced as an analgesic at a time when surgery was no joke. Faraday quickly revealed his true colours as a theoretician and inventor, and the proud possessor of a mind at least as brilliant and ingenious as Davy’s. They collaborated on designing a safety lamp for miners, then fell out and remained distant up to Davy’s death in Geneva in 1829.
It was Faraday who turned the Institution’s aim of ‘diffusing knowledge’ into an art and a public spectacle. In addition to the ‘Juvenile Lectures’ at Christmas, he set up weekly Friday Evening Discourses, in which a leading scientist would hold forth on their subject, without hesitation, repetition or deviation, for just an hour and not a minute longer. He set a fine example, eventually giving nineteen Christmas Lectures and numerous Discourses. These included the first public appearance of his electric generator in 1831, and a show-stopping display of the disinhibiting effects of nitrous oxide, gamely demonstrated by Sir John Hippisley. The highlights of Friday Evening at the Institution included the Discourse in August 1897 when J.J. Thomson introduced the electron to the world. Many of these events played to an overfull house of at least 1,000 (over twice the number of seats in the auditorium), and regularly caused such congestion that Albemarle Street was designated the capital’s first one-way thoroughfare.
Thereafter, the Institution became calmer and duller. In 1877, the ‘ruthless’ Scottish chemist James Dewar took over as Professor of Chemistry, and was appointed the first director of the new Davy Faraday Research Laboratory twenty years later. Dewar was interested in extremely low temperatures and had invented a vacuum flask for keeping liquids very hot or very cold. He succeeded in first liquefying, and then solidifying, hydrogen. That was in 1899. After that, his research tailed off, just as molecular activity ceases when the temperature of a gas winds down towards absolute zero. At the time of his death in 1923, he was eighty-one years old, had done nothing new for over fifteen years, and had no intention of retiring from the Institution.
When William Bragg arrived to replace Dewar, the Institution had declined into a mournful place with ‘the forlorn feeling of a harbour when the tide has gone out’. Chiselling the Institution out of the mediocrity in which it had become fossilised was a harder task than he had faced in Adelaide nearly forty years earlier, but he was determined to recapture its former glory. As well as his brilliant mind and a steely will to succeed, the sixty-one-year-old Bragg brought ‘charm and suavity’ which ‘rapidly won all hearts’.
Bragg led from the front, as Faraday had done, in taking the excitement and fun of science out of the laboratory and into the real world. His media were the Institution’s lecture theatre, the radio and the printed page. His own Christmas Lectures, especially ‘The Universe of Light’ (1931), were hugely popular, as were the books which gathered together each series of talks. One of the countless ‘Juveniles’ whose eyes were opened by Bragg was thirteen-year-old Dorothy Crowfoot. She succeeded in her aim to follow in his footsteps, but unlike him, actually went to Stockholm to collect her Nobel Prize for X-ray crystallography.
Occasional messages were not broadcast with absolute clarity. When Erwin Schrödinger, Nobel prizewinner in Physics, came to the Institution in 1929 to talk about Wave Theory, the audience included an ‘enthusiastic but unmathematical’ yachtsman who evidently had not read the fine print. Otherwise, the Royal Institution was back where it belonged, at the forefront of public engagement, and Sir William Bragg had established himself as Britain’s greatest living ambassador for science.
Young blood
Raising the Institution’s research from the grave was Bragg’s biggest challenge. This was partly his own fault, because his ambition was to make the place a world-class centre for X-ray crystallography. He began by bringing in three young scientists whom he had recruited at University College. All were in their early twenties and gifted in different and complementary ways; they worked well together and were living proof that the whole is greater than the sum of the parts. When eventually they went their separate ways, they spread the Bragg diaspora to Oxford, Cambridge and Leeds and each found fame for creating a new niche in X-ray crystallography. And later still, one of them was destined to obtain the first evidence that the DNA molecule has a regular helical structure.
The ‘pillar’ of Bragg’s new research unit was twenty-year-old Kathleen Yardley, who had caught his eye a year earlier. He had been examining the BSc in Physics at London University, and she made herself conspicuous by getting top marks (actually the highest marks in over a decade). Yardley was a Norfolk girl but had been born in southern Ireland. So had John Desmond Bernal, who left Ireland with a scholarship to Cambridge to study Natural Sciences. There, he acquired a First, the nickname ‘Sage’ (for his apparent omniscience), and the conviction that communism was the only solution to the ills of the planet. Bernal cut a bohemian figure, with flowing hair, a laissez-faire approach to fidelity and a passion for broadcasting on a wavelength somewhere between Marx and Lenin.
The third founding member of Bragg’s X-ray crystallography group was William (Bill, to everyone) Astbury, the breezy and talkative son of a Potteries town near Stoke-on-Trent (Figure 10.1). Like Bernal, Astbury had gone to Cambridge and began collecting Firsts in Chemistry and Mineralogy. The war had hacked a swathe through his studies, but it also introduced him to X-rays. That first encounter was not exactly at the cutting edge of science. As a lowly assistant in a Royal Army Medical Corps unit in County Cork, Astbury was court-martialled (twice) for failing to look after His Majesty’s X-ray equipment, but was acquitted both times when the damage was blamed on ‘An Act of God or the King’s Enemies’. More positively, he met an Irish girl, Frances Gould, and returned to Cork after the war to carry her off to London as his wife.
Yardley, Bernal and Astbury formed a close-knit team, with the same hands-off leadership, free discussion and shared excitement as in Thomas Morgan’s group, but without the claustrophobic togetherness of the Fly Room. For light relief, they had ping-pong, introduced by Astbury to spice up lunchtimes. They each cut their teeth on projects that had nothing to do with the research that would make them famous, and which led nowhere exciting. Bernal worked on crystals of metal alloys, and Yardley and Astbury on the structures of simple organic acids. Astbury and Yardley also produced an exact guide to the X-ray characteristics for every possible shape of the basic units that make up crystals. Tabulated X-ray data for the examination of the 230 space-groups by homogeneous X-ray analysis (1925) might not sound like a bestseller, but the ‘Astbury-Yardley Tables’ were an instant hit and rapidly became the crystallographers’ bible.
Figure 10.1 William (Bill) Astbury.
For Bernal, these were ‘the most exciting years of my scientific life’, packed with inventiveness, improvisation and ‘exceptional luck’. He found Bragg’s X-ray spectrometer fiddly beyond endurance and so built an automatic X-ray camera from odds and ends that could have been nicked from a scrapyard: ‘a few pieces of brass tubing’, aluminium and lead foil, glass from miners’ lamps, bicycle clips (to hold the film), the innards of an alarm clock to rotate the crystal – and ‘plenty of sealing-wax to stick everything together’. It worked, and produced stunning X-ray photographs which for the first time revealed the beautifully layered structure of graphite.*
Bernal also provided thumbnail sketches of daily life (‘routine’ would be completely the wrong word) in the Institution. His own laboratory was underground, in the chilly basement where Faraday had built some of his electromagnetic machines, and which was still ‘festooned with flasks full of Dewar’s rare gases’. It was there that, at a critical moment in a crucial experiment, he dropped a tiny specimen of an alloy more precious than gold. He never found it, but the spectacle of Bernal ‘on his knees, looking for his one and only crystal of gamma-bronze’ was Kathleen Yardley’s ‘most joyous recollection of this period’. Bernal also conducted some ‘crazy experiments’, such as taking X-ray diffraction photographs of the leg of a live frog, with the muscles either relaxed or stimulated electrically to make them contract. Like the frog, science did not leap forward as a result.
Their personalities were an eclectic and lively mix. Kathleen Yardley was ‘unobtrusive but had such an underlying strength of character that she became from the outset the presiding genius of the place’. Astbury was ‘slapdash and imaginative, with unflagging enthusiasm which kept us all going’. They wandered in and out of each other’s rooms when a thought or a question struck. At the informal gatherings, with everyone lying back in easy chairs in the study of Bragg’s flat, discussion also ranged freely, ‘with continual comments and interruptions, especially from Astbury’. And presiding over them all was the ‘Old Man’, Sir William Bragg: ‘gentle and humane . . . tall and rosy-cheeked with dark, friendly eyes’. As Bernal wrote, ‘None of those there, then in their twenties, would ever have wanted to work anywhere else . . . We had to be kicked out.’
Double act
Meanwhile, Bragg the Younger had been building his own empire, some 160 miles to the north of his father’s. In 1919, he had moved to the Chair of Physics in Manchester to replace Ernest Rutherford, who had been poached by Cambridge to succeed J.J. Thomson as their Professor of Physics and Director of the Cavendish Laboratory.
Lawrence Bragg applied himself to creating the northern powerhouse of X-ray crystallography with the same energy that his father had focused on the Royal Institution. His team marched steadily through the mineral kingdom, with bold forays into the ‘silicates’ which form beautiful but complicated crystals. Conventional mathematics could not cope with analysing the diffraction patterns of these cryptic molecules, but an exceedingly clever process called ‘Fourier transformation’ galloped to the rescue. For those intimidated by mathematical equations which hunt in packs, Fourier transformation is the kind of thing that makes you want to lie down in a quiet, dark place. Luckily, it did the trick and enabled the Manchester team to conquer new realms of crystallographic complexity.
In parallel with the growing power of data analysis, the hardware of X-ray diffraction was also in constant evolution. High-energy X-rays of a single wavelength, together with improved camera design, were now providing ever-clearer diffraction photographs. While Lawrence and his team delved deeper into minerals, William’s group tightened its grip on carbon-containing organic molecules. Within a few years, father and son had carved up the field between them, and were pushing out its boundaries with incredible speed.
Pastures new
During 1927, Bragg’s three fledglings all began to display signs of restlessness. The first to fly the nest was Kathleen Yardley, who had become Mrs Lonsdale and was bound for Leeds where her physicist husband had accepted a post with the Silk Research Association. Lonsdale quickly proved that she was no camp follower, by winning a scholarship to continue her X-ray crystallography work in the Chemistry Department. Before long, she cracked the structure of the organic compound, hexamethylbenzene and sent Bragg a copy of her forthcoming paper. This showed that the benzene ring, one of the fundamental building-blocks of organic chemistry, was indeed the flat hexagon that had been portrayed hypothetically in textbooks for over sixty years. Bragg wrote approvingly, ‘I think your new result is perfectly delightful.’ Lonsdale’s sojourn in Leeds was to last only two years, as her husband’s next job was back in London. She returned to the Institution to continue her work, now a busy mother with a young family but still a temporary research assistant, living from one short-term grant to the next.
Later in 1927, an opportunity came up that appealed greatly to both Astbury and Bernal: a lectureship in mineralogy at Cambridge. Both were called to interview and each performed true to type. Astbury’s response to a question about collaborative research was a curt, ‘I’m not prepared to be anybody’s lackey.’ Bernal, his hair streaming like a banner for extra dramatic effect, took them by storm with a forty-five-minute oration about his research vision. The Professor of Mineralogy, dazed by Bernal’s ‘eloquent, passionate, masterly, prophetic’ exposition, later explained that ‘There was nothing for it but to elect him.’
Astbury was badly stung by his failure to get the job and took an uncharacteristically long time to recover his joie de vivre. But being a no-nonsense Northerner, he would not have read too many omens into the bang with which the Royal Institution saw out 1927. A couple of hours after everyone had gone home after the Christmas Lecture on ‘Engines’, the electricity substation which supplied the Davy Faraday Laboratory blew up. Luckily, the only casualty was the original tiered lecture theatre, but it was completely wrecked. It took several years for a near-replica to be built, as faithfully as rather more stringent safety regulations would allow.
By then, Astbury’s days at the Institution were numbered. The seeds of his salvation had been sown a couple of years earlier, while Bragg was gathering ideas for his 1926 Royal Institution Lecture on The imperfect crystallisation of common things’. Bragg had set out to explore materials whose internal structures remained mysterious, partly because they were too ubiquitous to be exciting. Among his props was an item that seemed almost as crazy as Bernal’s attempt to capture the diffraction pattern of a frog’s leg.
Bragg asked Astbury to take an X-ray photograph of a single human hair. The diffraction pattern that Astbury obtained from the hair was ‘imperfect’, just as Bragg had expected: not the clean-cut geometrical array of dots thrown out by a mineral crystal, but a messier landscape of fuzzy streaks, spots and arcs. Astbury was intrigued, and after the disappointment in Cambridge, began to look deeper into biological materials that were less ordered and more mysterious than crystals.
Everything fell into place in the spring of 1928, when Bragg received a letter from the University of Leeds. The Worshipful Company of Clothmakers had stumped up the cash to create a new lecturer post in Textiles, specifically to inject the rigour of physics into the subject. Did Bragg know of any suitable candidates? He did, and he laid it on thick. Dr William Astbury was ‘a brilliant man . . . energetic and persevering . . . has done first-class research which is quoted everywhere . . . he has the research spirit’. In short, ‘the perfect person for the job’. And just as Cambridge had been obliged to appoint Bernal, Leeds snapped up Astbury.
The chain of events that guided Astbury to Leeds began with the human hair that he had strung up in the X-ray camera for Bragg’s lecture a couple of years earlier. It would be an exaggeration to suggest that Astbury’s future hung on that hair, but he would soon have good reason to be grateful to Bragg for introducing him to ‘the imperfect crystallisation of common things’. This apparently unpromising material led to an astonishingly rich research theme and a successful career – and to a discovery that would bring Astbury to within spitting distance, if not a hair’s breadth, of the chance to rewrite the story of the double helix.
Contactless transactions
Even as Bill Astbury settled into his last few months at the Royal Institution, a new tributary of that river of scientific discovery was coming into existence. It appeared from nowhere, like a spring welling up out of dry ground, and for over a decade it would show no inclination to flow in any particular direction.
Its presence was first revealed when a distinguished German scientist came to visit an English colleague in August 1927, within days of the interview that carried J.D. Bernal off to Cambridge. The German was thoroughly familiar with his colleague’s work but had no idea what he looked like, because the Englishman was an odd fellow who never went to scientific meetings. The Englishman’s laboratory was vastly inferior to the German’s state-of-the-art facilities, and might even have given the impression of being run by two men and a dog. However, the German was knocked sideways when he heard about something that the Englishman had stumbled upon – and the first thing he did on returning home was to repeat those experiments, because he could not believe what he had been told.
It was certainly controversial stuff. The Englishman claimed that he had transferred inherited characteristics into living organisms, not through the normal process of reproduction but by manipulating dead, inert material on his laboratory bench. The recipients of the transfer were permanently altered as a result, and they faithfully transmitted that change to their progeny. The transformation was obvious enough to be seen with the naked eye and, if you had the misfortune to be a mouse, it made the difference between life and death.
Bill Astbury and the other Englishman worked in parallel universes; neither would have seen any common ground between their research interests, and neither would have predicted that these could ever come together. The other man’s heretical research was published in early 1928, just as Astbury was preparing to leave the Royal Institution for Leeds. The paper appeared in a journal that Astbury never had any reason to look at, and it would have made no sense to him even if someone had put it on his desk, open at the right page, for him to read. Ironically, the two men were near neighbours. If Astbury had turned east out of the Royal Institution, a brisk fifteen-minute stroll through the streets of Theatreland would have brought him to the shabby little laboratory near Covent Garden where those peculiar experiments had been done.
To make sense of what happened, we first need to make a brief diversion into the English Midlands, to an industrial town just thirty miles south of where Bill Astbury grew up. There, we shall meet one of the real villains in the saga of DNA: tiny, brutal and deadly.