Alexander Thomas Dick 1911-1982
This memoir was originally published in Historical Records of Australian Science, vol.6, no.3, 1986.
Alexander Thomas Dick Alick to his friends was born in Melbourne on 9 February 1911 and died in Adelaide on 3 July 1982.
He was the second son of John Laird Dick who was born in Glasgow, Scotland in 1874 and came to Australia in 1888 with two older brothers. They settled in Victoria where Dick's father, who was employed in the Victorian civil service, married Florence Mary Smith, born in Victoria of English parents. They had four children of whom Alick was the second, having an elder brother, who also became a chemist, and two younger sisters. Alick married Gwendda Muriel Harwood on 18 January 1946. They had two children, a son, Ian Robert and a daughter, Anne Elizabeth, both of whom are graduates of the University of Adelaide.
Dick's education began at South Yarra State School, Melbourne, from which he proceeded to Melbourne Church of England Grammar School where he reached matriculation standard in 1927. The subjects he studied included mathematics, chemistry and physics.
In 1928 he joined the Mount Lyell Chemical Works as a 'chemical cadet' but then spent fifteen months as a clerical officer awaiting a vacancy at the firm's Yarraville works. As this did not materialize he joined the laboratory staff of Francis Longmore and Co. in 1929 as assistant to the works manager and chief chemist at the firm's food products factory in West Melbourne.
While those two years afforded little useful experience or satisfaction, Dick took advantage of them by attending an evening course at Melbourne Technical College, at the completion of which he obtained the Public Analyst Certificate. There is no doubt that this analytical background later contributed substantially and effectively to Dick's approach to his research.
In 1930 he commenced a science course at the University of Melbourne, studying Chemistry, Physics, Botany, and Zoology in his first year; Chemistry (II), Biochemistry and Physiology, and Bacteriology in his second year; and Chemistry (III), Biochemistry and Physiology (II) and Bacteriology (II) in third year. He obtained honours in all subjects, his lowest position in the class lists being fourth.
With this background Dick applied for a position with the Council for Scientific and Industrial Research. In this he was successful, being appointed as a Junior Research Officer to the Animal Health Research Station, Townsville, where he took up duty on 9 January 1933. There he worked for five years with A.W. Turner (later FAA) on the investigation of contagious bovine pleuropneumonia. Those investigations were largely concerned with the biochemical and immunological properties of the causal organism and its metabolic requirements for growth in artificial media. The work resulted in the development of a vaccine that was largely instrumental in bringing this disease under control in Australia.
Dick demonstrated early in his career a useful administrative capacity that was soon recognised by his being given technical and administrative responsibility for a field station, 'Helenslee', west of Charters Towers. He was also given in 1936 administrative responsibility for the research station at Townsville and in 1937 supervised its closing down, the handing over of its activities to the Queensland Department of Agriculture and the transfer of the CSIR staff and equipment to Melbourne.
On his return to Melbourne, Dick was appointed Officer-in-Charge of the Chemical Pathology Section of the Division of Animal Health and Production based at the Parkville Laboratory under the direction of the then Chief of Division, L.B. Bull. For some years considerable sheep losses had been suffered in southern New South Wales and northern Victoria due to what came to be called 'toxaemic jaundice', and Bull was chairman of a committee directing a co-operative investigation into this problem. Dick was immediately involved in work relevant to toxaemic jaundice and was co-author of A Preliminary Note on the Aetiology of Enzootic Jaundice, or 'Yellows' of Sheep in Australia with Albiston, Bull and Keast. It was concluded that enzootic jaundice was due to a disturbance of copper metabolism associated with high storage values for copper in the liver and a sudden mobilisation of copper into the blood stream; that is, the disease was, at bottom, chronic copper poisoning. Dick's involvement in this programme was extensive and played a major part in unravelling the complex situation that was revealed. The story has been summarised briefly by Bull (Victorian Veterinary Proceedings, 1963-64, 17-20) who wrote: 'The CSIR Division had formed a Section of Chemical Pathology with Mr A.T. Dick in charge and thus prepared itself for an investigation which depended very much upon applied chemistry for success'. The validity of that statement is made clear later in Bull's review when he shows that they were concerned with three types of chronic copper poisoning in sheep, the first due to excess intake of copper usually from contaminated food or pasture, the second to liver damage produced most commonly by the consumption of plants containing pyrrolizidine alkaloids (caused, in the investigation in question, by the ingestion of Heliotropium europaeum), the third to mineral or inorganic imbalance resulting from a diet low in molybdenum and inorganic sulphate.
It is to this third category that Dick made his major scientific contribution. The discovery of the metabolic interrelation of molybdenum, copper and sulphate represented a significant contribution to knowledge and, to quote one authority, 'initiated a new era in trace element nutrition in which the significance of mineral interrelations has been highlighted in a dramatic way and stimulated a remarkably large series of similar types of study overseas'. Of Dick's twenty-six papers published during this period, some were concerned with techniques, a number with the development of analytical methods and the acquisition of data, and a substantial proportion to the effects of inorganic sulphate on molybdenum and copper metabolism in sheep.
It is appropriate at this point to acknowledge, as Dick would have wished, the skilled assistance of J.B. Bingley in both the extensive analytical work involved in the investigation and in the development of improved analytical techniques.
Dick and Bull reported in 1945 the first observations on the effects of molybdenum in the diet of ruminants in limiting the accumulation of copper in their tissues. Further observations by Dick indicated that there was a third factor involved which materially altered the control by molybdenum of copper accumulation, and this was identified as inorganic sulphate. He also showed that sulphate regulated molybdenum excretion in the urine and hence the level of molybdenum in circulating blood. The story was completed in what was Dick's last publication which postulated that sulphate is reduced to hydrogen sulphide which reacts with molybdates to form thiomolybdates. These combine with copper to form insoluble copper thiomolybdates thereby limiting the absorption of dietary copper.
Reference has been made to the role of Heliotropium europaeum in toxaemic jaundice. Bull and Dick were aware that a fatal liver disease of human beings in the USSR, due to consumption of grain contaminated with seed of Heliotropium lasiocarpum, was due to the presence in H. lasiocarpum of two alkaloids of the pyrrolizidine group, heliotrine and lasiocarpine. They arranged for a study of the alkaloids of H. europaeum first at the Department of Pharmacology, University of Melbourne, and then at the CSIR Division of Industrial Chemistry. The same two alkaloids, heliotrine and lasiocarpine, were shown to be present. At about this time, a committee was formed to investigate the so-called Kimberley Horse Disease that occurred on the cattle stations of northwestern Australia, and Bull's studies of the liver lesion involved convinced him that it resembled the pyrrolizidine alkaloidosis caused by Heliotropium europaeum. The horses were known to feed on Crotalaria species, of which Crotalaria retusa had been shown in the USA to contain a pyrrolizidine alkaloid, monocrotaline, that caused chronic liver disease.
An intensive study developed of pyrrolizidine alkaloids, their mode of action in giving rise to liver damage and their chemistry, involving Bull, Dick and C.C.J. Culvenor, an organic chemist in the CSIR Division of Industrial Chemistry. It is difficult now to sort out the individual contributions of Bull and Dick. Bull was unquestionably the pathologist and the leader, but given his heavy commitments as Chief of Division, it is probable that the driving force behind the experimental programme in the Division of Animal Health, maintaining its momentum and encouraging and integrating the work of the several collaborators, was Dick. Certainly he undertook the intensive testing of other pyrrolizidine alkaloids that established structure-activity correlations and made possible the prediction of the toxicity of other Australian plants containing the alkaloids. In due course the programme broadened in scope to include such plants as Echium, Crotalaria and Senecio species and took in aspects such as pharmacology and metabolism. The study of rumen metabolism of the alkaloids (initiated by A.T. Dann) was illuminating and led to the identification by Culvenor of 1-methylene pyrrolizidine as a non-toxic metabolite formed by an unusual reductive rearrangement. This led in turn to the recognition that the alkaloids had alkylating properties, which could account for their nucleo-toxic effects, and to the finding by Dick that the metabolic conversion of the alkaloids to 1-methylene pyrrolizidine could be promoted, in rumen liquor in vitro, by the addition of Vitamin B12, a point that he followed up vigorously. Dick's direct participation in this extensive and complex programme came to an end in 1965 when he was appointed Chief of the CSIRO Division of Nutritional Biochemistry in succession to H.R. Marston but not before the collaboration had led to the publication of the definitive text, The Pyrrolizidine Alkaloids, their Chemistry, Pathogenicity and other Biological Properties, by Bull, Culvenor and Dick. It may be not unreasonable to suggest that part of Dick's contribution to this successful collaboration was as a communication link between Bull the biologist and Culvenor the organic chemist. Arising from the pyrrolizidine programme Dick was co-author of eight scientific papers, mostly in collaboration with Bull and largely concerned with the effects of pure alkaloids on experimental animals.
In his career at Parkville, Dick displayed several characteristics that were to prove significant in his work as Chief of the Division of Nutritional Biochemistry. One of his former colleagues at Parkville described him as 'Platonic in argument' and added that it was a great delight to listen to discussions that were stimulating in their excellence. I myself had some experience of such discussions between Dick and Bull and believe that they contributed substantially to the clarification of ideas and so to the solution of research problems. Dick' s unyielding tenacity in argument when he believed his point to be valid was coupled with scrupulous honesty and lack of compromise in his dealings both with others and with himself. He was reserved but firmly fixed in his attitudes and was always prepared to take a lead in raising difficult and controversial issues. When he became aware of personal matters touching the welfare of those about him, he involved himself unobtrusively, with understanding and counsel. He was a good organiser who always gave full recognition to the contributions of his co-workers and supporting staff.
The Division for which Dick became responsible in 1965 presented a situation different from that of the Parkville laboratory. His predecessor had been an autocrat who had both generated and supervised the divisional research programmes on a day-to-day basis. Dick introduced a more democratic style of management and brought about a number of improvements in laboratory facilities including an increased ratio of technical to scientific staff. He saw himself as a 'facilitator' rather than a director. Nevertheless, as one of his staff wrote, Dick's 'somewhat rigid outlook did, however, lead to a critical assessment of divisional programmes and was a considerable benefit to the staff, encouraging them also to critically assess the directions and detailed procedures of their research projects. He did not approve of laissez-faire attitudes towards research and continually had in mind his perceived terms of reference for divisional activities'. Research sections were formed, each led by a senior scientist with a degree of autonomy, and senior staff were involved in decisions on proposed research programmes. Once a research proposal had been approved often after exhaustive and lengthy debate Dick did not interfere with its implementation.
Dick's perception of the terms of reference of his Division led to increasing and better defined emphasis on particular biological mechanisms. These included the metabolic interrelations of vitamin B12 and folic acid in cobalt-deficient sheep, the role of copper in brain development in the foetal lamb, the role of micro-organisms in the fermentation process and their energetic efficiency, the synthesis of S-amino acids in the rumen, the degradation of pyrrolizidine alkaloids in the rumen and the involvement of tryptamine alkaloids in the chronic poisoning of sheep by Phalaris tuberosa.
During his period as Chief, Dick's responsibilities were, of necessity, largely administrative and his opportunities for advancing his own research limited. He was, however, able to pursue his interests in the pyrrolizidine alkaloids and the interaction between molybdenum, sulphate and copper in the sheep; reference has already been made to his work on the conversion of molybdates to thiomolybdates with the consequent formation of insoluble copper thiomolybdates. He retired in February 1976 and did not undertake any further research.
Towards the end of Dick's tenure, the Executive of CSIRO approved a major change in the objectives of the Division, namely to move into the study of human nutritional problems, at the expense of existing programmes on ruminant nutrition. This change in direction was in no sense a criticism of the previous activities of the Division. The CSIRO Executive had become convinced that the organization should move into the field of human nutritional research and the preferred laboratory to undertake such investigations was the Division of Nutritional Biochemistry. Obviously the most appropriate time to bring about such a change was when a new chief of Division was to be appointed. Dick was naturally concerned about this decision and particularly in respect of its possible effect on the future of his staff.
Dick was admitted to the degree of Doctor of Science of the University of Melbourne in 1954 and in the same year was awarded the University's David Syme Research Prize (aeq). He was elected a Fellow of the Australian Academy of Science in 1964, appointed an officer of the Order of the British Empire in 1965 and in that same year awarded a Senior Foreign Scientist Fellowship by the US National Science Foundation.
Dick was an active member of the Royal Australian Chemical Institute, being admitted Associate in 1938 and Fellow in 1952. During the period 1940-1945 he was secretary for three years of the Institute's Biochemical Group and chairman for two years, and a member of the Victorian Branch Committee in 1946. He was also involved in other professional societies such as the Australian Society of Laboratory Technology, of which he was successively a member of council, vice-president and president and was elected honorary life member. Likewise he was a foundation member of the Victorian Society of Pathology and Experimental Medicine and became its president in 1958.
The writer acknowledges gratefully the very considerable assistance provided by Mr H.J. Lee, formerly Senior Principal Research Scientist of the CSIRO Division of Nutritional Biochemistry, Dr C.C.J. Culvenor of the Division of Animal Health, Mr J.B. Bingley, formerly of the Division of Animal Health, and Mr Colin Smith, CSIRO Archivist.
Sir Robert Price, former Chairman of CSIRO and, before that, Chief, Division of Organic Chemistry.