We had a glorious time together, working far into every night with new worlds unfolding before us in the silent laboratory . . . It was like discovering a new alluvial gold field where nuggets could be picked up on the ground, with thrilling new results every week.
Their working relationship was not always harmonious. Before Lawrence published his first paper on Bragg’s Law, his father mentioned in two letters to Nature that ‘my son’ [unnamed] had come up with a theory which explained all the spots on von Laue’s photographs. Lawrence resented this off-hand treatment, especially as many assumed that the Bragg of Bragg’s Law must be his father. Bragg Senior made amends by praising his son’s contribution when he was invited to the prestigious Solvay Conference in Brussels in October 1913. As a result, Lawrence received a postcard from Brussels with congratulatory messages from Einstein, Rutherford and Marie Curie.
The Braggs’ successes did not go unnoticed. In 1915, they followed in the footsteps of Rutherford and Roentgen by being awarded – jointly – the Barnard Gold Medal of the American National Academy of Sciences. Shortly after that, their book, X-Rays and Crystal Structure, was published to universal acclaim. In the introduction, William went out of his way to ‘make one point clear . . . My son is responsible for the “reflection” idea which has made it possible to advance the work of unravelling crystal structure.’
But by then, force majeure had intervened, and their time was no longer their own.
The blast of war
The ultimatum for the German Army to withdraw from Belgium expired at 11 p.m. British Summer Time – midnight in Germany – on 4 August 1914. Winston Churchill, then First Lord of the Admiralty, recalled that ‘a rustle of movement’ swept through the room on the first stroke of Big Ben. The War Telegram – ‘COMMENCE HOSTILITIES AGAINST GERMANY’ – had already been sent by the time Churchill walked across Horse Guards Parade to the Cabinet Room and told the Prime Minister that ‘the deed was done’.
The declaration of war broke up the Bragg X-ray crystallography team. William was recruited by Rutherford into a top-secret research programme to detect U-boats. Lawrence and his younger brother Bob joined up as soon as hostilities began. Bob went into the British Expeditionary Force which moved through France and was drawn inexorably towards the eastern Mediterranean. Lawrence spent several pointless months with former huntsmen in the Horse Artillery before salvation came in July 1915: a summons to the War Office in London which made him ‘walk on air’.
He was posted to ‘Maps HQ’ in Flanders, to perfect a ‘sound-ranging’ apparatus for locating enemy guns. An array of microphones had been tried out but the distant bang was swamped by the supersonic crack of the shell in flight, which arrived first. Bragg experienced this interference at first hand, by using the latrine when the British guns were firing nearby. The latrine was a closed box which communicated with the outside through the waste pipe; before he heard each bang, the shock-wave from the shell travelling overhead would lift his buttocks off the lavatory seat. Bragg eventually solved the problem with the help of a corporal who had been a physicist at Imperial College in London. Their improved sound-ranging system could pinpoint German guns up to eleven miles away, and was crucial to the Allied victories at Cambrai and Amiens.
While in Flanders, William received two momentous pieces of news. The first, in early September 1915, reported that Bragg, Robert Charles, of the Royal Field Artillery, had died of his wounds at Gallipoli. At home in Leeds, his father announced gruffly that ‘Bob’s gone’ and seemed to cope by immersing himself in his work; but his mother was devastated and never fully recovered from Bob’s death.
The second piece of intelligence helped to lift the gloom. In mid-November, Lawrence wrote home to thank his father for his ‘cheery letter’. This had informed him that they had both been awarded the Nobel Prize in Physics. To celebrate, the priest in whose house Lawrence and his team were billeted dug out a prize of his own from the cellar: a bottle of Lachrymae Christi. This was an appropriate place for Christ’s tears to flow. A few kilometres to the north was a once beautiful and prosperous Flemish city that few in the wider world knew about until July 1917. The city was called Ypres.
The Braggs were just two of the many scientists who served their country with distinction during the war. Mercifully, Lawrence was at a safe distance from Ypres in April 1916, when an ominous grey-green cloud rolled across the ground towards the French lines. The cloud consisted of chlorine gas, chosen for its ability to blind, incapacitate and kill. This was the start of ‘Operation Disinfection’ which was personally supervised by Fritz Haber, a renowned chemist and Director of the Kaiser Wilhelm Institute for Physics and Electrochemistry at Dahlem in Berlin.
Haber’s career had been built around benign gases, nitrogen and hydrogen, which he combined to make ammonia. This discovery was truly revolutionary: ammonia synthesised by the ‘Haber Process’ was the basis for cheap fertilisers and ultimately would feed half the world’s population. Haber never tried to excuse his work on killing people with poison gas: ‘During peace time, a scientist belongs to the world, but during war time, he belongs to his country.’ Soon after the successful experiment at Ypres (22,000 casualties, 6,000 dead), he was off to the Eastern Front where chlorine worked even better on the Russian Army. The timing of that trip was unfortunate – just days after his wife Clara shot herself with his revolver, and was found dying by their twelve-year-old son.
Haber’s philosophy would have stuck in the throat of Albrecht Kossel, whose life had turned grim. In 1913, his beloved wife Luise fell ill with acute pancreatitis, which was ‘uniformly fatal’ and a horrific way to die. Kossel sank into ‘a great melancholy’ punctuated by violent mood swings. The war also ‘weighed heavily’ on Kossel’s mind; his greatest fear was that the U-boats would target American ships and drag the United States, a country which he respected and remembered with affection, into the conflict.
So Kossel buried himself in his work, now concentrating on the histone proteins rather than nucleic acids. He also turned his back on the war effort. When Reich officials told him to reassure the public that their rations were adequate, he refused; he could see that Germany was heading for famine and could ‘never pass off a lie as the truth’. His reward was a smear campaign, accusing him of disloyalty to the Fatherland.
In October 1914, he faced an even tougher challenge. Ninety-three intellectuals – including internationally acclaimed authors, composers, artists, theologians, doctors and scientists – signed an open letter to express their anguish over what was happening in Germany. These ‘heralds of peace’, for whom ‘the legacy of Goethe, Beethoven and Kant is just as sacred as our hearths and homes’, begged ‘The Civilised World’ to ‘Have faith in us!’
Albrecht Kossel, Nobel laureate, refused to sign. And the absence of his signature from the ‘Manifesto of the Ninety-Three’ was as deafening as if he had shouted his treachery from the rooftops.
To end all wars
As Kossel had predicted, America entered the war in early 1917 when the German U-boat fleet turned on American ships carrying food and supplies to England. On 6 April 1917, the US Congress voted for ‘a war to end all wars, to make the world safe for democracy’.
In New York, the Rockefeller Institute and Hospital were rebranded as ‘US Auxiliary Laboratory No. 1’ and ‘US Auxiliary Hospital No. 1’. Like Lieutenant-Colonel Simon Flexner, most staff signed up as commissioned officers in the US Army and joined the war effort. Microbiologists developed immune sera to treat battlefield infections such as gas gangrene and dysentery. Physiologists worked out how to store blood for transfusion. And Phoebus Levene’s research was diverted into painkillers, sedatives and antidotes to mustard gas.
Across town at Columbia University, Thomas Hunt Morgan’s team in the Fly Room continued their painstaking trawl of the chromosomes of Drosophila, more or less as usual. By the time America entered the war, they had clocked up nearly a thousand mutations.
The hostilities came close
r to the man who first convincingly pinned heredity on the chromosomes. Charles Sutton had become Assistant Professor in Surgery at the University of Kansas, specialising in heroic operations on the head and neck. He spent three lively months in 1915 at an American field hospital north-east of Paris and returned to Kansas with plenty of material to write a book on battlefield surgery. On the morning of 7 November 1916, Sutton operated on three cases of ruptured appendix – while suffering the same symptoms. His patients all survived, but he was less fortunate when his own turn on the operating table came that afternoon.
Charles Sutton was just thirty-nine years old when he died. He was unmarried and had no children to mourn his passing, but the Sutton-Boveri chromosomal theory of inheritance had just celebrated its fourteenth birthday.
Normal service resumed
After the war, Lawrence Bragg returned to Cambridge in late 1918 with an unusual collection of gongs – OBE, Military Cross and Nobel Prize – while his father settled into the Chair of Physics at University College in London. Both immediately picked up X-ray diffraction where they had left off.
The war also ended well for the pioneers who had discovered quantum theory and the method for ‘synthesising ammonia from its elements’; Max Planck and Fritz Haber were awarded the 1918 Nobel Prizes in Physics and Chemistry. Both attended the post-war Nobel presentation ceremony in Stockholm on 2 June 1920. The citation for Haber acknowledged that he had been ‘appointed a consultant to the German War Office and organised gas attacks’, but explained how he fulfilled Alfred Nobel’s directive that the prizes should be awarded to those who had ‘conferred the greatest benefit on mankind’: ‘Haber lived for science, both for its own sake and also for the influence it has in moulding human life and human culture and civilisation.’
Both Braggs were invited to the same ceremony, but they declined. It was not until 1922 that Lawrence went to Stockholm to collect their joint prize and to deliver his Nobel lecture on ‘The diffraction of X-rays by crystals’. He apologised for the ‘unfortunate circumstances’ which had prevented him from attending in 1920, but did not explain what these were or why the other recipient of the prize was not there. However, his father had given the reason two years earlier, in a letter to a friend soon after the first invitation was issued. ‘We are not going,’ he wrote, ‘because Germans will probably be there.’
When the war ended, Albrecht Kossel was five years off retirement and at last ‘his life ran quietly’. His final year in post, 1923, was enlivened by trips to Paris, for the Louis Pasteur Centenary Conference, and to Edinburgh, to receive an honorary doctorate and present a paper at the 11th International Physiological Congress. At both places, he was surprised to be welcomed warmly and treated like a scientific celebrity.
The Physiological Congress in Edinburgh began with J.J.R. MacLeod (Toronto) lecturing on insulin which was about to win him a Nobel Prize, and ended with another Nobel laureate, Ivan Pavlov (Petrograd). However, the show was stolen by the melancholy, self-effacing man whose life had been running so quietly. When Kossel took the stage to give his lecture, all 500 delegates jumped up and gave him a standing ovation that lasted several minutes.
It was not just Kossel’s scientific brilliance or happy memories of his own congress in Heidelberg that pushed them all to their feet. Two years earlier, the New York Times had printed a vitriolic piece about a document that provoked outrage when it was published in 1914, just after Germany’s ‘Rape of Belgium’. The ‘Manifesto of the Ninety-Three’ had been written to justify German aggression. The ninety-three intellectuals insisted that Germany had not wanted the war; due to forces beyond their control, it would have been ‘suicide on our part’ not to have gone into Belgium. Yes, Belgians had been killed, but only ‘in the bitterest self-defence’, and it was ‘with aching hearts’ that German troops had been ‘obliged to fire a part of Louvain as a punishment’ for the treachery of its inhabitants.
Three years after the war ended, the Times managed to contact seventy-six of the surviving signatories; sixty of them expressed regret, ‘in some cases amounting almost to remorse’, while others said they had not known what they were signing. The editor of the Times made clear his disgust: ‘In either case, they stamped themselves as unworthy ever again to be regarded as men of intellectual or moral integrity. If they would lie about the facts of the war, there is no assurance that they would not with equal glibness lie about the facts of chemistry or geology or biology.’
The ninety-three intellectuals included many of Germany’s greatest scientific names, complete with Nobel prizewinners: Emil Fischer (Chemistry, 1902), who brought clarity to sugars and purines; Adolf Baeyer (Chemistry, 1905), inventor of indigo and barbiturates; Wilhelm Roentgen (Physics, 1901), the discoverer of X-rays; Max Planck (Physics, 1918), the founding father of quantum theory; and Fritz Haber (Chemistry, 1918), synthesiser of ammonia and mastermind of Operation Disinfection.
But not Albrecht Kossel (Physiology or Medicine, 1910). We presume that Kossel’s beloved Luise, had she lived another year and seen where nationalism had taken Germany, would have been proud of him.
* In 1913, his father was awarded a hereditary title for his services to the state; Laue was also permitted to tack the aristocratic ‘von’ in front of his surname.
† Some of these were specimens filched from the Mineralogy Department Museum in Cambridge.
9
THE SAD DEMISE OF A PROMISING CANDIDATE
Nowadays, we picture DNA as a massively long molecule that spells out all the billions of characters of the human genome. Knowing the origins of that understanding, we might also envisage the double helix as the intertwining of strands of research representing ‘DNA chemistry’, ‘DNA structure’ and ‘genes’. At the start of the 1920s, however, there was no hint of any such unity. Each of the research strands appeared to be running in isolation through a conceptual vacuum that excluded all other lines of enquiry. And any attempt to weave them all together into a coherent whole would have been dismissed as an act of folly rather than an inspired leap of lateral thinking.
After the Great War, the thread marked ‘genes’ steadily gained substance. Even William Bateson, who had initially seen ‘formidable difficulties’ in accepting that chromosomes were the receptacles of heredity, was shamelessly seduced by the idea of genes on a string. In December 1921, Bateson went to Toronto to do penance before the American Association for the Advancement of Science. In his keynote address, he praised ‘the marvels of cytology, which until recently I had seen only through a glass darkly’, and added, ‘I come at this Christmas season to lay my respectful homage before the stars that have arisen in the West.’ The brightest of those stars was Thomas Hunt Morgan, the ‘thickhead’ whom Bateson had so despised a decade earlier and who had become a world leader in ‘genetics’, the now well-established science which owed its name to Bateson.
A few months later, Morgan was invited to London by the Royal Society to give the 1922 Croonian Lecture. The Fly Room production line had continued to churn out new mutations, and Morgan was able to report the sequences of over 2,000 ‘factors’ along the four chromosomes of Drosophila (Figure 9.1). His presentation was so brilliant, and the evidence so solid, that nobody now would have thought of attacking his claim that ‘genes are material particles actually lying in and forming part of the chromosome’.
Meanwhile, research into the chemistry and structure of the nucleic acids had not progressed so smoothly. These strands of enquiry had been going nowhere for some time and were about to be cut short – by the two men who knew more about these compounds than anybody else.
Figure 9.1 Mutations affecting the eyes and wings of the fruit fly, Drosophila, described by Thomas Hunt Morgan and his team in 1922.
Zum Gedächtnis
After the war ended for everyone else, hostilities grumbled on for Phoebus Levene. Exchanges of fire continued with the irascible Walter Jones at Johns Hopkins and, across the Rockefeller campus, with Simon Flexner. Jones still ins
isted that the unidentified sugar in thymus nuclei acid was a hexose, and managed to irritate Levene at every opportunity; naturally, his name remained taboo in Levene’s lab.
Flexner had failed to rein in Levene’s overspending. His irate ‘You are embarrassing the Executive Committee . . . The Bursar will not pay any bills in excess of the budget’ fell on deaf ears; so did the plaintive ‘a single item threatens to spoil our otherwise good relationship: budget’. The pair also crossed swords over a high-profile mugging at Grand Central Station. In July 1923, Ivan Pavlov toured America en route to the Pasteur centenary celebration in Paris and the International Physiological Congress in Edinburgh. Flushed with his conquest of New York, Pavlov had just settled himself on the train to Yale when two ruffians grabbed the seventy-four-year-old and relieved him of his wallet and passport. The incident caused embarrassment for Pavlov’s American hosts and the dramatic headline in the New York Times, ‘RUSSIAN SCIENTIST BARRED FROM BRITAIN’. A friendly Russian émigré saved the day by spiriting up money and a visa, just in time for Pavlov to sail to England. The great man’s saviour was his former student, Phoebus Levene, and the cash came from the coffers of the Rockefeller Institute. True to form, Flexner reprimanded Levene, this time for breaking the Institute’s rule which banned employees from involvement in any ‘political’ activity.
It was thanks to Pavlov that, in 1929 and after twenty years of trying, Levene finally identified the elusive sugar in thymus nucleic acid. A recent report that the dog’s digestive juices broke down nucleic acids prompted Levene to perform a surgical operation which he had watched during a visit to Pavlov’s laboratory in St Petersburg. The procedure allowed him to inject thymus nucleic acid into the small intestine of a living dog and suck out the contents at intervals. The dog was untroubled throughout;
Unravelling the Double Helix Page 13