Hal Dixon was a biochemist, a Life Fellow of King's College, Cambridge, who was cleverer than most of his colleagues, enthusiastic and energetic, but who never achieved the heights of scientific success that his abilities merited. But he was a wonderful colleague, friend and teacher.
He was born Henry Berkeley Franks Dixon in 1928 in Dublin, where his father, H.H. Dixon, was an eminent botanist at Trinity College. Hal was introduced to thinking about science at an early age; his father published a note to Nature in 1938 based on the observations of "a nine-year-old boy", who was his son.
In 1946 Hal Dixon went up to King's College, Cambridge, where he got a double First in Biochemistry. He stayed in the Biochemistry Department to do a PhD with Frank Young on peptide hormones, about which very little was known at the time. This work led to Dixon's long-term interest in the chemistry of proteins. During his later career, for example, he developed a technique for altering the structure of the terminal amino acid in a protein chain, thereby making possible studies of its function – nowadays that kind of thing is done genetically, but could not be then. His deep understanding of principles enabled him to give us all insights in how pH affects the way proteins work. And his knowledge of organic chemistry allowed his suggestion of a possible drug for Wilson's disease, a potentially fatal problem with copper metabolism.
Those scientists who knew and worked with Dixon agreed that he was one of the cleverest people they knew. His intelligence was sharp, and his understanding usually much deeper than one's own. He had a boyish and infectious enthusiasm for science; his Christmas card mixed family information with chemical equations, assuming a level of interest that came naturally to him, but was perhaps not always shared by his readers. That enthusiasm was also apparent when he worked in the lab. I remember failing to restrain him from removing samples from incubation in the oven too early, thereby threatening the experiments – but also allowing us to know a bit earlier what the outcome might be. He just couldn't wait.
Dixon's services to science were not restricted to the lab. He worked on the complicated ways in which enzymes are named and catalogued. That kind of thing is not glamorous, but it is essential; it needs to be done by someone who really understands it and is committed to it. He was chairman of the Nomenclature Committee of the International Union of Biochemistry, and deputy chairman of the editorial board of the Biochemical Journal. In the early 1960s, he and his family spent a whole year in the Soviet Union, where good biochemistry was being done as Soviet biology emerged from the darkness of Trofim Lysenko.
Dixon was a dedicated and sometimes inspiring teacher, leading by example and personal contact as much as in classes, and developing laboratory experiments that demonstrated fundamental principles with great clarity and limited equipment. It was his own deep understanding of these principles, perhaps, that enabled him to do that so well. But it also made him a demanding tutor and a fearsome examiner; perhaps more so than he realised.
So why then did relatively little of Hal Dixon's work make a real impact on science and why did he remain little known outside Cambridge? He remained a very chemical biochemist while most people were becoming more biological. He couldn't, or maybe didn't want to, build up a powerful group of his own. But, most importantly he was too clever and too enthusiastic to apply himself to a particular area or to make the strategic selection successful scientists do of a problem that is soluble and whose solution will be important. Perhaps also he was too selfless, and too anxious to help others to give his own career the attention it deserved.
The second focus of his working life was King's College, where had been a Fellow since 1953. He was a Director of Studies from 1961, guiding students through their courses for 20 years, as well at other times as financial tutor, Praelector, and editor of the college Register. His election by his colleagues as Vice-Provost from 1981 to 1986 was a symbol of their confidence in him, and he was successful in the job because of his kindness and sincerity and also because of the pertinacity he brought to problems, worrying about them until they were solved. Sadly, though, for a Kingsman, he was tone-deaf and could not appreciate the music in the chapel that makes the college so famous.
The chapel itself was important to him, because he was a strong and convinced Christian. I do not share that belief, but when I think of the Christian virtues, I think of him. He was honest, forthright, helpful, kind and in a real sense good.
Simon van Heyningen
Henry Berkeley Franks Dixon, biochemist: born Dublin 16 May 1928; Fellow, King's College, Cambridge 1953-2008, Vice-Provost 1981-86; married 1957 Heather Spittle (two sons, one daughter); died Cambridge 30 July 2008.