OBITUARY: Professor R. P. Bell

R. P. Bell was one of Britain's most distinguished physical chemists and a great Balliol man. He served Balliol College, Oxford, as Tutor for Admissions, Senior Tutor and Vice-Master, and in 1967, after 34 years as a Fellow, was elected to an Honorary Fellowship.

As a tutor he had some idiosyncratic ideas. The first term of physical chemistry tutorials was simply appalling. Each student was made to copy out a series of Victorian papers by T.W. Richards on the accurate determination of the atomic weight of silver. This exercise was so stupefyingly boring that people either changed to PPE or else demonstrated that they had the endurance to make a success of the chemistry course. Once one progressed to Bell's own field of reaction kinetics, he was an excellent tutor. He had a formidable intellect, of cool clarity and ruthless objectivity.

Bell was a small man with rather large ears and a delightful twinkle in his eye. Perched on his chair he would peruse the weekly essay with a slim gold propelling pencil, pouncing on spelling mistakes, mathematical non-sequiturs or errors in logic. There was a quiet and deadly courtesy: - "I do not quite understand . . ." (In this sentence one realised that the first person singular should be replaced by the second.) As a tutor or supervisor he treated his pupils as equals. With Hugh Longuet-Higgins, he famously wrote a paper on the structure of borane which arose from a third year tutorial.

Bell's great contribution to science was the study of proton transfer reactions and the elucidation of the nature of acids and bases in solution. Proton transfer reactions are ubiquitous; for instance most biochemical transformations will involve proton transfers, since organic molecules always have a skin of hydrogen atoms.

His work combined high-powered theory with ingenious and innovative experimentation. On the theoretical side he was one of the first in 1933 to use quantum theory to predict that when a proton reacts it might tunnel through the energy barrier rather than go over the top. He also pioneered studies in which a hydrogen atom is replaced with the heavier isotope deuterium. The consequent change in the rate of reaction gives unique and detailed understanding of the route by which the reaction takes place.

Examples of Bell's experimental ingenuity would include the early use of a tape recorder to record data on a faster time-scale, the study of rates of reaction using small home- made thermocouples to measure the heat emitted by the reaction and the study of fast brominations using platinum electrodes to measure very low concentrations of bromine.

In 1954 the Faraday Society held an important discussion meeting on the study of fast reactions. On the first day Bell described his new tape- recording techniques which could measure rates of reaction that took only 10 -9 seconds. Manfred Eigen rightly won the Nobel Prize for Chemistry in 1967 for developing techniques to measure rapid chemical reactions, and it was perhaps Bell's misfortune not to have made a single great advance but rather to have contributed a lifetime of theory and associated experiments.

Ronald Percy Bell was born in 1907 and in 1924 arrived at Balliol College as an Exhibitioner to read for a chemistry degree under the redoubtable Sir Harold Hartley. In 1928 he won the Gibbs Prize awarded to the best chemist in Finals and he wrote to Hartley, "May it long continue to be a Balliol perquisite."

In the years that Bell was a Fellow, from 1933 to 1967, his early wish was largely fulfilled. Between 1928 and 1932 he worked in Copenhagen with the great Danish physical chemist J.N. Bronsted. A rumour arose that Bell had fallen in with a troupe of somewhat disreputable actors, so much so that one morning he found a note from Bronsted on his apparatus saying that since Mr Bell had not been seen for three months Bronsted assumed he had returned to England. Bronsted cannot have been too displeased because he wrote to Hartley: "It gives me great pleasure to state that Mr Bell has showed himself as an unusually bright and able young man." Bell returned to succeed Hartley as Bedford Lecturer in Chemistry at Balliol in 1932 without completing a doctorate; throughout most of his working life he gloried in being simply Mr Bell.

His work was recognised by many honours. In 1944 he was elected to the Royal Society and served on its council. In 1972 he became a foreign associate of the National Academy in the United States. He served as President of the Faraday Society in 1956 and as a Vice- President of the Royal Society of Chemistry in 1958.

Ronnie Bell did not care about rank and was utterly without pomposity. But as well as the cool dispassionate man of reason there was also a warm appreciation of the good things of life. He loved music and was a keen supporter of the Balliol concerts. He smoked Havana cigars and therefore his laboratory had a far more satisfying aroma than usual. He delighted in his cottage on Buttermere, in the Lake District. All these qualities meant that he was a strong candidate for the Mastership of Balliol in the election that took place in 1964, but in the end the Fellows preferred Christopher Hill.

In 1967 Bell was persuaded to be the first Professor of Chemistry at Stirling University. He presided over the design and construction of a most elegant laboratory and served on the University Court and on the Academic Council. He retired in 1975 but continued to take an interest in protons and Balliol. For instance more recently he described to the Balliol archivist, Dr John Jones, the occupation of the college by Chatham House during the Second World War. Bell was employed on the Danish desk and wrote, "One of my triumphs was to persuade the FO Establishment Officer that as a half-time employee I was entitled to twice as much leave as anyone else."

John Albery

Ronald Percy Bell, chemist: born 24 November 1907; Fellow of Balliol College 1933-67; FRS 1944; Professor of Chemistry, Stirling University 1967-75 (Emeritus); FRSE 1968; Honorary Research Professor of Chemistry, Leeds University 1976-82; married 1931 Margery West (one son); died Leeds 9 January 1996.