Australian Academy of Science Biographical Memoirs of Deceased Fellows Originally prepared for publication as part of Bright Sparcs by the Australian Science Archives Project.

Albert Lloyd George Rees, 1916-1989

By Alan Walsh and J.B. Willis

The paternal forebears of A.L.G. Rees were Welsh. His great-grandfather, Thomas Rees, born in Carmarthen, South Wales, in 1805, and his father, George Percival Rees, born in New Zealand in 1872, were nonconformist ministers. The latter gave sixty years of distinguished service to Baptist churches throughout Australia, including twenty years as General Secretary of the Baptist Union of Victoria and a term as President General of the Baptist Church of Australia.

The Revd G.P. Rees married Edith Mary Target, a seamstress, in Melbourne on 24 April 1900. They had six children, four girls and two boys. A.L.G. Rees, born on 15 January 1916, was the youngest. The selection of Lloyd George as two of his Christian names reflects his father's Welsh origins and his admiration for the great Welsh statesman and his outstanding leadership as Prime Minister of Britain during the First World War.

School and University Career

A.L.G. Rees had a distinguished career at Carey, where he excelled as a scholar and as a sportsman. In his final year, 1933, he was Dux (for the second successive year), Head Prefect, Captain of School, and winner of prizes in English, Mathematics and Science. He often expressed his gratitude for the teaching he received at Carey. Arthur Sandell, a contemporary of Rees and a fellow prefect, has stated that various teachers, including Rex Rees, had a great influence on Lloyd's development as a scholar. However, he believes that it was his chemistry and physics master, Mark Stump, who deserves most credit for fostering in Rees an interest in science, and a special love of physics and chemistry. It also seems certain that Lloyd owed much to his father, who was a strict disciplinarian and instilled the work ethic in all his children. According to Lloyd's widow, Marion, it was also his father who developed his son's love and correct usage of the English language.

Rees was also a keen sportsman. In his final year he was cricket captain, and for his splendid performance as a batsman and slip fielder was awarded a Junior Membership of the Melbourne Cricket Club. He also won his football colours and an athletic sports medallion for his hurdling.

At an address given to a Carey School Assembly after Rees's death, Alfred Mellor, a personal friend since their school days at Carey, stated: 'A prime aspiration for Lloyd was excellence'. All who worked with him would surely endorse that comment most heartily.

Towards the end of his schooldays Lloyd decided that he wanted to be a scientist. J.L. Farrant has related how in his last year at school Rees, in his school uniform and with his cap in his pocket, walked into the Head Office of the Council for Scientific and Industrial Research (CSIR) at 314 Albert Street, East Melbourne, and told the receptionist that he wanted to see Dr David Rivett, at that time Chief Executive Officer of CSIR and a former Professor of Chemistry at the University of Melbourne. Rivett said 'send him up' Rees explained that, as he was the youngest of six children of a clergyman, his family could not afford to send him to University in the normal way, so he wondered if any other avenue was available. Impressed by Rees's temerity, Rivett asked if he would be willing to be a laboratory assistant in the University Chemistry Department, to which Lloyd replied 'yes of course'. Rivett promptly telephoned Professor E.J. Hartung, his successor as Professor of Chemistry at Melbourne University, and said 'I have a likely lad here. He wants to be a scientist. I'm sending him up to see you and I hope you will be able to start him off with a job as a lab. boy'. Professor G.E. Rogers, FAA, has informed one of us (AW) that he had heard Rivett relate this story with great pleasure. Neither Rees nor Rivett could have foreseen how their relationship would develop in the years ahead.

In 1934 Rees began his university course while working part-time as a laboratory assistant engaged in routine store-room duties in the Chemistry Department. Professor Hartung later wrote to one of us (JBW):

We always had several of these lads [laboratory cadets] and gave them time off to enable them to complete three of the four subjects for the first year of the Science course, and corresponding time in their later years so that a diligent lad could obtain a BSc in four years instead of the usual three. However Lloyd, in spite of his cadet duties performed in an exemplary manner, managed all four Science subjects in his first year, and his results were so good that I advised him to drop his cadetship and concentrate entirely on his studies . . . This advice was followed with the best of results.

Rees gained his BSc with distinction in 1936 and in the following year enrolled as a full-time postgraduate student in chemistry. His supervisor for the MSc degree was Dr N.S. (later Sir Noel) Bayliss. Thus began an association which in the years ahead developed into a warm personal friendship. The first project on which Rees worked with Bayliss was the study of the spectrum of bromine in various solvents. Bayliss has commented: 'Lloyd soon showed that he was a man of quite unusual ability, both with his experimental aptitude and with his grasp of the theoretical principles behind our research problem'

Early in 1938 Bayliss took up his appointment as Professor of Chemistry at the University of Western Australia. Rees remained in Melbourne and began studying the effects of foreign gases on the spectrum of bromine. Throughout these investigations he was in frequent correspondence with Bayliss. At the end of 1938 he graduated MSc and shared the Dixson and Professor Kernot Research Scholarships in Final Honours Chemistry. He also learned that his application for a Beit Scientific Research Fellowship for postgraduate research at Imperial College, London, had been successful. He planned to continue his researches in Melbourne until leaving for London in time to arrive for the beginning of the autumn term of 1939. There was, however, a surprising turn of events, described by Bayliss as follows:

At the end of 1938 a crisis arose in my department in Perth. Owing to George Tattersall's illness there would be nobody to teach organic chemistry for the whole of the first term of 1939. There was no one available in Western Australia, and the time was too short to advertise the vacancy in the usual way. When I turned to Hartung for advice, he suggested Lloyd, who though by no means an organic chemist, could no doubt cope with the situation competently for a term.

It was during this period that Lloyd developed his concept of the solvent cage as fundamental to the interpretation of solution spectra, demonstrating the capacity he had to discern the fundamentals of any problem that he tackled. Our relationship of teacher and pupil began to reverse itself: certainly since those days Lloyd has taught me far more than I taught him.

Rees's time in Perth was an eventful and happy one. His research flourished and he greatly enjoyed having day-to-day contact with Bayliss. In retrospect at least he also enjoyed his lecturing duties, and in later years often recalled with pleasure his struggles to 'keep half a page ahead of his students'. But the most profound impact on his life resulting from his sojourn in Perth in 1939 was undoubtedly his meeting with Miss Marion Mofflin, who later became his wife. Marion was born in Perth, and was serving as a Sister in the Royal Perth Hospital when she and Rees first met.

Rees left Perth at the end of second term, hoping to arrive at Imperial College in London for the autumn term of 1939. However, when he was midway across the Indian Ocean the Second World War broke out; the ship was diverted around the Cape of Good Hope and took an erratic journey under blackout conditions before arriving in London.

Wartime Activities in England 1939-1944

Rees's research activities before leaving Australia were all in the field of optical spectroscopy, though he was becoming interested in other physical techniques, such as electron diffraction, for which no facilities existed in Australia at that time. At Imperial College, however, he had the opportunity of contact with Professors L.C. Martin and G.I. Finch, who had done pioneering work in England on the electron microscope and electron diffraction camera respectively. His reading on these topics resulted in the writing of several review papers at this time.

Philips Electrical Industries

The first three sections formed were for: (a) studies of the synthesis and characterisation of inorganic phosphors of the type used in cathode ray tubes and fluorescent lamps, and of the fundamental processes occurring in luminescence and phosphorescence; (b) investigations of thermionic emission; and (c) determination of the properties and usage of getters, combined with a study of the basic mechanism responsible for their characteristics.

Later, an X-ray crystallographic section was set up for general service work and analytical spectrochemical equipment was installed. Further staff were recruited to the Research and Development Group to work on the synthesis of silicone resins and for secret studies of materials of high dielectric constant. Yet another research project related to the electrophoretic deposition of barium strontium carbonate. There were also many problems submitted by the production factory. The Materials Laboratory, which had a strong metallurgical group working on TICONAL magnets and a small chemical factory producing emitter pastes and paints, also submitted problems.

The experience Rees gained during his work at Imperial College and with Philips Electrical Industries U.K. greatly broadened his range of interests and was invaluable preparation for his future career in chemical physics.

Return to Australia: Establishment of the Chemical Physics Section

The functions of the new Section were described thus by Wark in 1945:

This Section will have two main functions the first being to apply modern physical methods in the solution of chemical problems arising in other Sections of the Division's activities, the second being to conduct independent research. It is intended that extra-mural work will be undertaken by the service side of the Section. Techniques which will be established in the near future are electron microscopy and diffraction, X-ray diffraction and spectroscopy - including mass spectroscopy and infra-red spectroscopy. The introduction of some of these techniques for the first time in Australia should be of service to both primary and secondary industry.

Rees was indeed fortunate in being appointed to the Division of Industrial Chemistry, with Wark as Chief. Wark's philosophy of research, like that of his mentor, Rivett, was that selection of staff was of paramount importance and that top-quality scientific staff could be left without interference to tackle the problems for which they were appointed. As a result, Rees was given a great measure of freedom in the choice of research topics for his future Section and in the selection of staff and equipment. A 'chemist by training and a physicist by inclination and adoption', he regarded the subject of chemical physics as 'the elucidation of chemical problems by the application of modern physical experimental methods, and on the theoretical side by the application of quantum mechanics and statistical mechanics'. His approach to research was very similar to that of Wark, and was expressed on many occasions in terms such as:

By its nature chemical physics finds wide application in all phases of physical and biological science and of industry, so that it is natural that the work [of the Chemical Physics Section] should be directed not by the problems of a specific industry, but rather to certain classes of problem originating in many industries and other technical and scientific fields. The broad objective of research in chemical physics is the understanding of chemical behaviour, a matter which is basic to the operation of chemical industry and which impinges directly nowadays on other industries, such as the electrical industry, and on problems of function, structure and mechanism in biological and medical science. Frequently a single piece of research may have significant implications in more than one applied area . . . often the important applications of fundamental work are in quite unexpected areas . . .

He set about the establishment of the Section with characteristic speed and energy. Less than two months after taking up his appointment at Fishermens Bend he had prepared a statement of immediate and future space requirements for the proposed Section and had drawn up detailed proposals for a building to house it. Though supported by Wark and the Council, these were rejected by the Treasury. Despite continued pressure from Rees and Wark, it was not until the mid-1960s that Chemical Physics was able to move from the very unsatisfactory accommodation at Fishermens Bend to a specially designed laboratory at Clayton.

Rees early envisaged that the major areas of the Section's research would be protein structure investigations, chemico-physical studies of the solid state, the determination of molecular structure and energetics, and the development of new and improved chemico-physical techniques. Since the nature of the work in these subjects required the use of sophisticated instruments, one of his first actions was to establish an instrument workshop under the supervision of a professional engineer. The creation of the nucleus of a specialised workshop of world standard was a step years ahead of its time: in 1946 it was generally assumed that Australia would continue to import all but the very simplest scientific instruments from overseas. Rees always gave unwavering support to the needs of the workshop - the Instrument Laboratory, as he called it - and received the affection and loyalty of the professional, technical and trades staff who worked there. The workshop played a vital role in almost all the activities of Chemical Physics and more than justified the foresight of Rees in establishing it.

The first major instrument to be delivered was the RCA electron microscope with which Rees had acquired experience during his journey back to Australia. An electron diffraction camera was designed and constructed in the Section, and by 1947 X-ray diffraction equipment, a mass spectrometer, an ultra-violet and an infra-red spectrometer had been purchased. In the three years following his arrival at Fishermens Bend, Rees recruited the key research staff who would, as the Section expanded, become leaders of groups devoted to these techniques. In retrospect it is apparent that he chose well: almost without exception they justified his expectations with regard to scientific ability and leadership.

Rees himself carried out work on electron microscopy and diffraction as well as spectroscopy and the defect solid state. He was personally involved in everything that went on in the Section, and for many years delegated very little supervisory responsibility, even to those who had been appointed to form the nuclei of the groups concerned with the various techniques that had been set up. It was inevitable that, in the course of time and as these specialists became experts in their particular areas, this close central control would be somewhat relaxed, though Rees always made the decisions on budgetary, staff and promotion matters and closely scrutinised and criticized all scientific papers before they were submitted for publication. Many members of the Section improved their writing skills considerably as a result of his insistence on high standards of presentation.

As early as the mid-1940s Wark was foreshadowing that the sections of the Division of Industrial Chemistry must be given greater autonomy in the future, and in the following decade this course of action became increasingly desirable. By 1954 the Division was one of the largest in CSIRO, with a research staff of 106 and a total staff of over 300, Chemical Physics alone had nearly 30 research and experimental staff. Wark, who regarded the Division as filling the role of a national chemical laboratory, recommended to the Executive of CSIRO in 1957 that the name should be changed to 'The National Chemical Laboratory of Australia'. However, in October 1958 the Executive decided that the Division would be known as 'The CSIRO Chemical Research Laboratories', with Wark as Director, the Sections of Chemical Physics and Physical Chemistry would become Divisions with Rees and K.L. Sutherland as their respective Chiefs, and the other Sections would retain the same names as Sections of the Chemical Research Laboratories.

When in January 1961 Wark was appointed to the Executive of CSIRO, each of the Chiefs and Officers-in-Charge was made responsible directly to the Executive for the scientific work of his own Division or Section, while the overall management of the Laboratories was entrusted to a committee of Chiefs and Officers-in-Charge under the chairmanship of Rees. This was not a very happy arrangement, and was particularly unsatisfactory in that Rees had to fill two sometimes conflicting roles on the committee, as an impartial chairman and as the protagonist of one of the six Divisions and Sections that made up the Chemical Research Laboratories. The problem was exacerbated by the fact that several of the Divisions, including Chemical Physics, were in the process of acquiring their own accommodation in various locations. The Chemical Research Laboratories were disbanded in August 1970, by which time most of the constituent Divisions had left Fishermens Bend.

The creation of the Division of Chemical Physics with himself as Chief was a notable achievement for Rees and his research team. The Executive of CSIRO had recognized both the importance of the subject of chemical physics and also the achievements of his Section bearing that name. Another goal was to be reached in the next few years - the accommodation of his Division in a building specially designed for it. The Section was located initially in the main brick building of the Division of Industrial Chemistry at Fishermens Bend, but the Instrument Laboratory, when established in 1946, had to be housed in a discarded army hut. As the Section expanded, several research groups particularly X-ray diffraction and theoretical chemistry, were accommodated in similar huts. In early 1954, the Instrument Laboratory moved into a makeshift factory bay with a temporary mezzanine floor, and high-resolution spectroscopy and interferometry were carried out in a similar bay. The diffraction grating ruling project had to be housed in a small hut specially constructed for the purpose. Since 1948 Rees and Wark had made repeated requests for a building for Chemical Physics, but ten years later Wark was still complaining to the Executive:

. . . half of our slums of which you have a photograph are tenanted by Chemical Physics . . . [and] to be told now - after thirteen years of negotiation - that it [the provision of new buildings for the Division of Industrial Chemistry and in particular for Chemical Physics] does not have any priority at all has been almost beyond my comprehension.

In 1960 CSIRO purchased from the Victorian government a little under 38 acres (15.4 ha) of land adjoining the northern boundary of the proposed new Monash University at Clayton, a southeastern suburb of Melbourne. It was agreed that the Chemical Research Laboratories were to be transferred to Clayton in stages, probably over a period of ten years, the Division of Chemical Physics being the first to move.

Rees threw himself into the problems of designing a new building with all the energy and determination he had shown fifteen years earlier in the establishment of the Chemical Physics Section. It was almost entirely due to his persistence that a no. of novel features were incorporated in the building, including a special basement area for optical work and full air conditioning - almost unheard of in government buildings at that time. The building was officially opened on 1 April 1966 by Senator the Honorable J.G. Gorton and named 'The David Rivett Laboratory' in honour of a man who had been an inspiration to Rees from the very beginning of his career and who was revered by all in CSIRO.

In 1971 an extension to the David Rivett Laboratory (the north-west wing) was added, to provide more adequate accommodation for the Spectroscopy Section and for the Library. Some months after Rees's retirement in 1978, the Library was officially designated 'The Lloyd Rees Library'

Rees and the Scientific Instrument Industry

For some years after the end of the war much equipment was in short supply, or even unavailable, for export to Australia and delivery times on some items were prohibitively long. Also funds were limited. None of the staff [of Chemical Physics] were prepared, however, to sit around waiting for the equipment they needed, so some instruments were designed and constructed ab initio while those damaged in transit were repaired in-house rather than returned to overseas manufacturers. Again those instruments whose design and therefore performance were inadequate were redesigned. Chemical Physics was fortunate in having, since its establishment, an instrument workshop/laboratory with facilities for design and draughting, mechanical and electronic work, glass-blowing, and at a later stage, optical finishing work, in which the construction and modification of instruments could be undertaken.

It was not surprising that towards the end of the 1940s the canteen table conversations began to canvass the feasibility of manufacture in Australia as a means of capitalising on the advantages of the resulting novel equipment. There was even a suggestion that we might finance the venture ourselves, but it didn't take long to dismiss that proposal as impracticable.

This was in fact the milieu that prompted consideration of the concept of an indigenous scientific instrument industry for Australia, at least as far as we were concerned. My own attitude may have been influenced by an overseas trip in 1951, during which I was greatly impressed by the transformation of the scientific instrument industry since 1944, particularly in the USA, where academic scientists and engineers were moving into the industrial area with obvious success and prosperity.

At the beginning of 1952 Rees prepared a formal document for the Chief Executive Officer of CSIRO, F.W.G. White, entitled 'The establishment of a scientific instrument industry in Australia'. He outlined the advantages to Australia of such a development and examined its economic and technological feasibility. He envisaged several possible structures for an industry of this kind and recommended that 'it should be sponsored by the Government but financed by private capital, and relying initially at least on government scientific institutions for technical advice and guidelines'. He appended data concerning six major instruments developed in the Chemical Physics Section and assessed for each the potential market and the cost of manufacture.

The development of various new types of instrument in the Section during the first few years of its existence, including a 'double-pass' infra-red spectrometer that was patented and licensed to an overseas manufacturer, encouraged Rees in his ambition to have such new instruments made commercially in Australia. From this time onwards he campaigned continually on this theme and discussed it with members of the CSIRO Executive, with leaders of industry, with banks, with potential manufacturers and with prospective customers. Largely as a result of his enthusiasm and persistence, manufacture of several small instruments developed in the Section, such as an ultra-nicrotome and a stabilized power supply, was undertaken by Australian firms by the mid-1950s.

The invention of the atomic absorption spectrophotometer in the Section and its development as a means of chemical analysis caused Rees to decide that the Section should have its own optical workshop to support its increasing research effort related to optical and spectroscopic instruments. D.A. Davies, the head of the Instrument Laboratory, had been attempting to produce diffraction gratings for use in spectroscopic instruments by an ingenious and apparently simple replication process proposed by Sir Thomas Merton, but in 1968 decided that to produce diffraction gratings of sufficiently high quality for this purpose would require the construction of a conventional grating-ruling engine. Rees approved this recommendation, which was in many ways a bold step: no matter how successful the outcome, there still remained the unanswered question of the uses to which the gratings could ultimately be put. Subsequent events, however, more than justified the optimism with which he committed Chemical Physics to a formidable item of open-ended research and development.

The audacity of Rees in undertaking this immensely difficult project was remarkable. His decision to do so meant that, if successful, Australia would have the facilities to manufacture various types of spectroscopic equipment. In particular, the prospects for local manufacture of atomic absorption instruments would become immensely brighter. The subsequent successful development of the Australian spectroscopic industry is well known. Walter Slavin, a senior member of a large American scientific instrument company, has paid this tribute to Rees and his Division: 'Rarely has a technical field owed so much to a single laboratory as atomic absorption spectroscopy owes to the Division of Chemical Physics of the CSIRO . . . where atomic absorption was conceived, nurtured, pioneered, applied, and instrumented'.

Right up to his retirement, Rees continued to support other major instrument developments in his Division and did his utmost to ensure that wherever possible they were commercialized by Australian firms. His contributions to the development of an Australian scientific instrument industry were recognised by the award in 1987 of the Australian Academy of Science's first Ian William Wark Medal, established to encourage those who work at the boundaries of science and industry. His Wark Lecture, 'Science in Bondage', was an expression of his concern for the trend in Australia towards more short-term research directed to specific targets at the expense of longer-term fundamental studies. The scientific instrument industry itself honoured him by election to Honorary Life Membership of the Australian Scientific Industry Association.

Association with Learned Societies and Educational Institutions

Rees was honoured by the award of the Institute's Rennie (1945), Smith (1951) and Leighton (1970) Medals.

Australian Academy of Science and the International Scientific Unions

Another contribution by Rees was his collaboration with N.S. Bayliss in establishing the Australian Spectroscopy Conferences, which have been held biennially since 1957 and have attracted many of the world's leading spectroscopists.

Rees served as the Academy's Secretary Physical Sciences, 1964-8 and as Foreign Secretary, 1969-73, carrying out each of these onerous tasks with typical energy and enthusiasm. He was a member of the Executive Committee and Bureau, IUPAC, 1963-73, and from 1969 to 1971 served as President of IUPAC, the only Australian to have been so honoured. During his term of office he was President of the XXII International Congress of Pure and Applied Chemistry, which was held in Sydney in 1969. He was also a member of the Executive Committee of the International Council of Scientific Unions and continued to serve on other committees of that body until 1976. F.W.G. Baker, who was Executive Secretary of ICSU during Rees's period of service to that body, wrote recently to one of us (JBW):

Our relationship was always friendly and we both had a pragmatic view that was communicated across the table or in the breaks, of some of the more esoteric and unworkable suggestions that can come up in any meeting. He was a useful and effective member of the Admissions Committee because of his lack of prejudice and open-mindedness, and a useful ally in expressing a point of view that it was not always possible for me to express. He was conscious of and concerned about the lack of visibility of ICSU and members of the ICSU family, and pushed hard . . . for the adoption of a recommendation on the subject, which was adopted in Leningrad in 1973. If he were still alive today I imagine he would be tempted to have another go on the same subject.

Lord Todd, Nobel laureate and former President of the Royal Society of London, has commented: 'I think it is fair to say that Lloyd has done more than anyone else to establish Australia as a force on the international scientific scene and this has been due in no small measure to his combination of toughness and ability to take decisions and his good humour and capacity to get on with all sorts of people'.

After Rees left the Academy Council in 1973 he continued to make various contributions to the Academy's activities. Of particular value was his collaboration with Professor F.J. Fenner in editing The Australian Academy of Science, the First Twenty-five Years. The editors describe the book as 'a narrative account of the main happenings that led to the formation of the Australian Academy of Science twenty-five years ago, and of what the Academy has accomplished, and failed to accomplish, up to March 1979'. Its 286 pages contain a mass of useful, authoritative information about the Academy, and are indispensable to all interested in the Academy's early history.

Rees also played a prominent role in the setting up and operation of the Science and Industry Forum, a standing committee of the Academy set up 'to bring together leading scientists, heads of major industrial organizations and other community leaders'. He was an enthusiastic supporter of the Forum from the time of its first formal meeting on 18 March 1967 until his death. The last Forum meeting he attended, in February 1989, was entitled 'The Rise and Rise of the Australian Scientific Instrument Industry', and he gave the opening address on 'Beginnings of the Industry: the Concept of a Scientific Instrument Industry in Australia'. The fact that a meeting of the National Science and Industry Forum should be devoted to a discussion of the Australian scientific instrument industry is itself a tribute to his remarkable vision and drive, which were of central importance in stimulating the growth of the industry from the early 1950s onwards. It was sad to note that during his lecture he was far from well, but it was appropriate that his last lecture was to a meeting sponsored by the Academy to which he had given so much devoted service during the 35 years of his Fellowship.

Tertiary Education

Law has commented:

His demanding standards of excellence, his forthright expression of his philosophical views on academic matters, his incisive ability in debate, his razor-sharp intellect and his uncompromising stands on fundamental issues were of vital consequence in the affairs of the VIC. He stood like a rocky cliff as the waves of disruption broke around him and retreated. More than any other person in the whole committee structure he was responsible for the academic standards demanded by the VIC of its Colleges.

(a) spectroscopy,
(b) electron microscopy,
(e) electron diffraction, and
(d) physics and chemistry of the defect solid state.

Spectroscopy

In the mid-1930s Bayliss had interpreted the continuous visible and ultra-violet absorption spectrum of bromine in terms of wave-mechanical theory, and Rees's first research, carried out with Bayliss, was to study the effect of solvents [(with R.G. Aickin & N.S. Bayliss) The effect of solvents on the continuous absorption spectrum of bromine. Proceedings of the Royal Society of London, A, 169 (1938), 234-45] and foreign gases [(with N.S. Bayliss) The effect of foreign gases on the continuous absorption spectrum of bromine. Nature 143 (1939), 560 & (with N.S. Bayliss) The effect of foreign gases on the continuous absorption spectrum of bromine. Transactions of the Faraday Society, 35 (1939), 792-800] on this absorption. The enhancement of absorption intensity found under these conditions was found to be related to the molecular polarization of the gas or solvent molecules and the breakdown of the selection rules [(with N.S. Bayliss) Interpretation of the visible absorption of bromine. Journal of Chemical Physics, 7 (1939), 854-5]. In a key paper [(with N.S. Bayliss) Electronic absorption spectra in solution: with special reference to the continuous absorption of the halogens. Journal of Chemical Physics, 8 (1940), 377-81] Bayliss and Rees interpreted changes in the wave-length of the absorption maximum between the gaseous phase and solution in terms of the 'cage' theory of liquids, in which each solute molecule is considered to be surrounded by a cage of solvent molecules whose relaxation time is long compared with the period of molecular vibration. They found the form of the potential function that must be added to the potential energy-interatomic distance curves of the gaseous molecules to give the corresponding curves for the dissolved molecules, and explained both the displacement of the absorption maximum and the change of symmetry of the resulting absorption curve. The 'cage effect' was to colour Rees's thinking on the interpretation of spectra in solution for many years to come.

After his return to Australia, Rees resumed his interest in the spectra of diatomic molecules. In the early 1930s Rydberg and Klein had developed a laborious graphical procedure for constructing the potential-energy curve for a diatomic molecule point-by-point without assuming an analytical expression for the potential function. Rees derived analytical expressions for this purpose and these, in contrast to the Rydberg-Klein method, enabled accurate evaluation of the potential-energy curve in the region of the minimum [The calculation of potential-energy curves from band-spectroscopic data. Proceedings of the Physical Society, 59 (1947), 998-1008.]. Professor D.P. Craig writes:

I never heard Lloyd make much of it himself but I have always been impressed by his contribution to the RKR (Rydberg-Klein-Rees) method for inverting experimental spectroscopic results to give a potential function for a diatomic molecule. No one had ever done anything to improve the original work in the ten or fifteen years after the appearance of the Klein paper during the '30s. After Lloyd's paper, which must have been published quite soon after his return to Australia and Fishermens Bend, the method grew into very substantial use. It must have been quoted hundreds of times in the spectroscopic literature and continues to be quoted nowadays, even though there are other inversion methods that I associate with the names of Mark Child and John Ogilvie particularly, which are also in use. It must be one of the most durable as well as the most quoted papers by an Australian physical chemist, so much so that he often receives the ultimate compliment of the paper's being quoted by initials only without the spelled-out names or an actual reference.

The installation of an infra-red spectrometer and the establishment of a spectroscopy group enabled Rees, in conjunction with Alan Walsh and N.S. Ham, to extend solvent effect studies into the infra-red region of the spectrum. Measurements of the effect of dissolved iodine on the infra-red absorption spectra of various solvents provided strong evidence against the formation of 'complexes' (a widely-held theory at that time) but were consistent with the predictions of the 'cage' theory [(with N.S. Ham and A. Walsh) Infra-red studies of solvent effects. Nature, 169 (1952), 110-1 & (with N.S. Ham & A. Walsh) Infra-red spectra of solutions of iodine in mesitylene. Journal of Chemical Physics, 20 (1952), 1336-7.].

With L. Mathieson, Rees re-analysed all the existing spectroscopic data on the iodine molecule and proposed several new assignments of bands [(with L. Mathieson) Electronic states and potential energy diagram of the iodine molecule. Journal of Chemical Physics, 25 (1956), 753-61]. His last spectroscopic work was the evaluation of the dissociation energy of the fluorine molecule, F**2, which cannot be determined by the usual spectroscopic method of measuring band convergence limits because its absorption is continuous. Various indirect methods suggested a value close to 37 kcal mole*-1, but attempts to extrapolate spectroscopic data from the other halogens led to a much higher value (ca. 63.5 kcal mole*-1). Rees used the continuous absorption spectrum of fluorine and the fundamental Raman frequency to compute the potential energy curve for the repulsive *lII**U state dissociating to two normal fluorine atoms, and showed that this curve was consistent with a value of 37.1 +/- 0.85 kcal mole*-l for the dissociation energy of the ground state [Electronic spectrum and dissociation energy of fluorine. Journal of Chemical Physics, 26 (1957), 1567-71; erratum, ibid., 27 (1957), 1424]. This is now the accepted value.

Electron Microscopy

With the departure from CSIRO in 1953 of E.H. Mercer, who had played the leading role in the electron microscopy study of wool fibres, this work came to a natural end. Rees had long hoped to be able to use the electron microscope to actually 'see' the crystal lattice itself, and improvements in the resolution of the instrument made over the years by J.L. Farrant brought the realization of this ambition significantly closer. In 1951 several workers, including Farrant, had observed fringe (moiré) patterns in electron micrographs of overlapping thin crystals, but no satisfactory explanation had yet been given for their occurrence. Dowell, Farrant and Rees showed that consideration of the angle between the fringes and the plane of deviation allowed an unambiguous interpretation of the origin of these fringes, and established the fact that the moiré pattern is essentially the Patterson function of the structure [Electron interference in lamellar crystals. Proceedings of the Third International Conference on Electron Microscopy, London, 1954, pp.279-85 & Electron interference fringes from superimposed lamellar crystals. Proceedings of the First Regional Conference on Electron Microscopy, Tokyo, 1956, pp.320-5]. They described the physical processes involved and discussed the possibility of observing patterns more directly related to the structure of the crystals than the Patterson function [The structural significance of moiré patterns. Proceedings of the Fourth International Conference on Electron Microscopy, Berlin, 1958, vol.  1, pp. 367-71].

Electron Diffraction

The high-resolution instrument constructed at Chemical Physics enabled them to make several important contributions to our understanding of fine structure in electron diffraction patterns. Study of small crystals of ZnO proved particularly fruitful in this connection. The breadths of the electron diffraction rings could be largely accounted for by contributions from the broadening due to the size and shape of the crystals and any spread of lattice parameters [(with J.A. Spink) Line-breadth in electron diffraction. Nature, 165 (1950), 645-6]. Progress was made towards the use of electron diffraction for the determination of the shape and dimensions of small crystals [(with J.A. Spink)The shape transform in electron diffraction by small crystals. Acta Crystallographica, 3 (1950), 316 & (with J.M. Crowley & J.A. Spink) The morphology of zinc oxide smoke particles. Proceedings of the Physical Society, B, 64 (1951), 638-44] although it soon became apparent that the observed effects were being complicated by dynamical diffraction effects. This led to the realization that the dynamical effects themselves contained information of significance concerning the crystal structure. A detailed study of the fine structure of electron diffraction spots from the small cubic crystals of MgO smoke confirmed the predictions of the dynamical theory and demonstrated that in this case the structure amplitudes used as a basis for crystal structure analysis could be derived from the linear dimensions, rather than the intensities, of the split spots.

Secondary elastic scattering of electrons had for some years been recognized as a cause of spurious effects found in electron diffraction patterns. Cowley, Rees and Spink analysed the types of phenomena attributable to this cause in the electron diffraction patterns of films of long-chain paraffins, and demonstrated that their origin lay in successive diffraction of electrons from two different single-crystal regions. They gave a quantitative treatment of the modification of the intensities in single-crystal patterns on the basis of secondary diffraction by parallel but non-coherent regions of the crystal, and derived expressions whereby observed intensities could be corrected for secondary scattering. Such corrections allowed them for dicetyl (C**32H**66) to make Fourier projections containing less spurious detail and indicating more clearly and accurately the positions of the hydrogen atoms.

It is appropriate that Rees's last publication in this field was a joint paper with Cowley in which they reviewed the various methods of deducing the structure of crystals from electron diffraction data, critically discussed the theory of electron scattering and the nature of the approximations made, and outlined the application of Fourier methods to the analysis of crystal structure using both diffraction intensities and fine structure of dynamic origin.

Professor Cowley wrote recently to one of us (JBW):

Of Lloyd's major contributions to electron diffraction, I can distinguish two: first, the introduction of modern, post-war technology such as was then being used for the new electron microscopes. Secondly his inspiration of the Chemical Physics group to get involved in, and fascinated by, the questions of the fundamental physics of the electron-diffraction phenomena (refraction effects, multiple scattering, dynamical diffraction). These of course led to the later developments of dynamic diffraction theory etc. We did some fairly routine applications jobs, of course, but Lloyd strongly encouraged us to get involved in the bigger, more fundamental problems and treat these applied jobs as minor, although interesting, diversions. ... In most respects, Lloyd had a great instinct for what was essential in the development of a technique and prodded people into an awareness of the directions to choose.

Another investigation at this time, probably originating in Philips' interest in the use of zirconium as a 'getter' to remove residual traces of gas from vacuum tubes, was a study of the solubility of hydrogen in zirconium and the effect of oxygen in solid solution on that solubility. Nine years later Rees published an interpretation of these results in terms of a statistical-mechanical theory for two-component interstitial solid solutions. This theory was based on a model which required all non-metal atoms to occupy interstitial sites in a perfect parent metal lattice; a refinement of the model took into account the reduction in the no. of available interstitial sites brought about by disorder in the parent lattice. The theory was applicable to any non-stoichiometric system in which one component was volatile or gaseous.

By the mid-1950s, it had long been apparent that an adequate symbolism was needed to describe defects in crystalline solids. Wagner and Schottky, pioneers of the subject in the 1930s, used a symbolism that had gradually suffered modifications brought about by the evolution of the chemistry and physics of the defect solid state. Rees, in his monograph on the chemistry of the defect solid state, proposed a more complete and convenient symbolism, which he presented to a IUPAC meeting in Madrid in 1956. It is however fair to say that his systematic and logical system has not been widely adopted by other workers in the field.

Rees the Man

I sense that Lloyd inherited an evangelist outlook from a father devoted to the Church, but applied it in a different direction. Nobody ever had more faith in the contribution that chemical physics could make to society. Nobody ever set out with greater determination to pass on that faith to others.

Since it was Sir Ian who had made the decision to create a Section of Chemical Physics in his Division of Industrial Chemistry, and to appoint Rees as its leader, he had followed the progress of Rees with great interest. He commented that the task required not only a top-quality scientist but also 'determination, dedication and drive':

Lloyd would have liked to proceed faster, much faster. Many are the times he chided -even berated-me and the Executive for not more nearly meeting his claims very modest claims, he was always at pains to emphasize. That's one of the functions of a good Chief, and Lloyd has been a superlatively good one. But however much Lloyd berated us, he had a very endearing trait: he abided by the umpire's decision. That doesn't mean that he would not later return to the attack: he's a dour fighter for a worthwhile cause-a man of great strength of character, with a physique to match. From my personal point of view I could not have found a better person to lead the Section.

As mentioned earlier, Rees was similarly fortunate: Wark aimed to have 60 per cent of the Division's projects quite fundamental in nature and was an enthusiastic supporter of Sir David Rivett's views on the administration of CSIR, such as giving the research scientist sufficient autonomy to get on with the job, fitting the organizational requirements to individuals, and recognizing that research initiatives tend to flow upwards from the research level.

An interesting feature of the staffing of the Chemical Physics Section was that it did not include anybody with an established record of achievement in the area of chemical physics in which he had been appointed to undertake research-indeed, several had no research experience whatever in their allotted field of research. In this respect they were in marked contrast to Rees, who after obtaining his PhD degree had had three years of wide-ranging experience in various branches of chemical physics while working with Philips. When appointed to CSIR, he was only 28, and all the research scientists appointed in the 1940s and '50s were even younger. But all of us were struck by the amazing breadth of his scientific knowledge. The task of setting up the Chemical Physics Section was a daunting one, but he always appeared quietly confident of coping with it. A lasting memory of those early years was the complete faith he had in the young and inexperienced staff appointed to his Section. Rees's prime aspiration to excellence was well known, and three of the contributors to the Tribute to Lloyd Rees describe him as a 'perfectionist'. One of the many manifestations of this characteristic was his love of order, neatness and cleanliness. He was always well-groomed, his car generally spotless inside and out, and his office invariably gave the impression that, whatever task was being tackled, it was entirely under control. Likewise, he was punctilious about keeping appointments, whether professional or personal.

The administration of the Section and later the Division of Chemical Physics was informal and egalitarian, and it was easy for any of his staff to meet with Rees. Even when the staff grew to more than one hundred, he knew every member as an individual and consciously looked after their interests. He was particularly supportive of staff members who were studying part-time for higher qualifications.

The range of Rees's responsibilities and activities might suggest a life with little time for recreation, but this was by no means the case. The backdrop to the domestic life of Lloyd and his wife Marion was the continuing development of their garden, whose splendour was a source of surprise and pleasure to their friends. It made a fitting setting for the generous hospitality which they extended to all their visitors. In the early days of the Section, Lloyd and Marion virtually offered open house to members of Chemical Physics, and they were particularly helpful to those of us who had arrived from interstate or overseas.

For the last thirty years of his life, Rees's favourite hobby was golf. He worked hard at it and made himself a useful golfer, but he is best known for his service as President of Riversdale Golf Club. His regular golfing partner, J.B. Dance, has claimed that he did a magnificent job and that under his leadership the finances, greens and fairways were never better.

When it was learned that Rees was terminally ill, all who had worked in the Division of Chemical Physics were greatly saddened. This was not simply the mourning for a man who had been a distinguished leader: it was more the general realization that they were losing a staunch and true friend. There was a general feeling that they should send him a message of thanks before he died, and it was decided to place a brass plaque below the painting of him in the Lloyd Rees Library. The plaque reads:

DR A.L.G. REES

Dr Lloyd Rees was appointed by CSIR in 1944 to create a Chemical Physics Section. This developed into the CSIRO Division of Chemical Physics, with Rees as Chief, a position he held until his retirement in 1978.

A chemist by training and a physicist by inclination, Rees established his Division as a leading centre of research in chemical physics. His vision led to the birth of the Australian scientific instrument industry.

This plaque was presented by former colleagues to record their gratitude for a dedicated and inspiring leader.

• 1936 Bsc - University of Melbourne
• 1938 Msc - University of Melbourne
• 1938 Shared Dixson and Professor Kernot Research Scholarships in Final Honours Chemistry
• 1938 Commonweath Research Grant
• 1939 Beit Scientific Research Fellowship (to Imperial College of Science and Technology, London)
• 1939 Free Passage to Europe
• 1941 Diploma of Imperial College
• 1941 PhD - University of London
• 1946 Rennie Medal - Australian Chemical Institute
• 1948 Fellow - Australian Chemical Institute
• 1948 Dsc - University of Melbourne
• 1951 Fellow - Australian and New Zealand Association for the Advancement of Science
• 1951 H.G. Smith Medal - Royal Australian Chemical Institute
• 1952 Liversidge Lecturer - Royal Society of New South Wales
• 1954 Fellow - Australian Academy of Science
• 1963 President, Section B (Chemistry) of the Australian and New Zealand Association for the Advancement of Science
• 1970 Leighton Memorial Medal - Royal Australian Chemical Institute
• 1970 Einstein Memorial Lecturer - Australian Institute of Physics
• 1977 DApplSc (honoris causa) - Victoria Institute of Colleges
• 1978 Commander of the British Empire (CBE)
• 1978 Lloyd Rees Library - CSIRO Division of Chemical Physics
• 1987 Ian William Wark Medallist and Lecturer - Australian Academy of Science
• 1989 Honorary Life Member - Australian Scientific Industry Association
• 1990 Lloyd Rees Memorial Lecture - Australian Academy of Science

acknowledgments

We have made considerable use of published material, particularly:

1. J.B. Willis, 'The Chemists of Australia: Dr A.L.G. Rees', Chemistry in Australia, 45(6) (1978), 157-9.

2. J.B. Willis, 'The CSIRO Division of Chemical Physics, 1944-86', Historical Records of Australian Science, 7(2) (1988), 153-77.

3. 'The Rise and Rise of the Scientific Instrument Industry in Australia: Report of the 45th Meeting of the National Science & Industry Forum, Thredbo, February 1989' (Australian Academy of Science, Canberra, 1989).

4. A Tribute to Lloyd Rees, published by colleague and friends of Dr A.L.G. Rees with the support of the CSIRO Division of Materials Science and Technology, Melbourne, 1989.

In addition to the colleagues and friends of Rees whose comments we have quoted directly in this memoir, we should like to thank F. Bryant, C.K. Coogan, J.L. Farrant, M. Williams and K. Stewart for information and reminiscences. We are particularly indebted to Mrs Marion Rees for providing details of her husband's forebears, for allowing us access to his personal papers, and for much other help.

Alan (later Sir Alan) Walsh, FAA, FRS, joined the research staff of the CSIR Division of Industrial Chemistry in 1946, and retired as Assistant Chief of the Division of Chemical Physics in 1977.

Dr Willis joined the research staff of the CSIR Division of Industrial Chemistry in 1948, and retired as Assistant Chief of the Division of Chemical Physics in 1986.

This memoir was originally published in Records of the Australian Academy of Science, vol. 9, no. 1, Canberra, Australia, 1983.