Every profession has its 'Grand Old Men' and 'Women'. With the passing of Lionel Batley Bull on May 5, 1978, the Veterinary Profession in Australia lost one of its acknowledged 'Grand Old Men'. He was born on April 27, 1889, at Ormond, Victoria, the second of four children of Thomas William Bull and Kate Marina Bull (née Harris). The family lived on a property in North Road, Ormond, and Thomas Bull's occupation has been recorded as 'Gentleman'.
An elder sister, Hilda, was one of Victoria's earliest women graduates in medicine, and a younger brother, Noel, was also a medical graduate. The younger sister, Vivien, was a physiotherapist. The family from all accounts enjoyed a leisurely, comfortable life on their property in Ormond, and there were always horses for riding and carriages available to them.
Lionel Bull was one of those privileged to attend University High School between about 1902 and 1905 during the period when Mr Otto Krome was the Head Master. It is a matter of history that many influential Melbourne men of the early part of the twentieth century received their secondary education under the great teachers, Adamson and Krome, of Melbourne University High School.
The decision to train in Veterinary Science may have been fortuitous; it may have been occasioned by his love of his father's horses, or he may have come in contact with Dr W.T. Kendall, who had established a veterinary college in Melbourne in 1888 with a four year course leading to a Licentiate in Veterinary Science. Kendall's Veterinary College was taken over by the University of Melbourne in 1908, and in 1909, John Anderson Gilruth took up his appointment as Dean of the Faculty of Veterinary Science and Professor of Veterinary Pathology in the University of Melbourne. The records show that in 1909 Bull transferred from the Kendall Academy and entered the third year of the licentiate course, and that he obtained honours in Pathology and Bacteriology, and was awarded the Swinburn Gold Medal in Pathology and honours in Veterinary Hygiene in that year. In 1910 he passed with honours all five subjects of the fourth year with a first class in Pathology and Bacteriology. He completed his course for the B.V.Sc. degree in all five subjects in November 1911, which was the first year that the degree was awarded by the University of Melbourne.
It is evident from his first paper on Enteritis in Native Animals that he had been engaged in research under Professor Gilruth since in his paper, read to the Royal Society of Victoria on December 14, 1911, he is described as a Government Research Scholar with the qualification LVSc. Apart from its intrinsic scientific interest, this paper is of interest because it is illustrated with some very careful line drawings made with the aid of the camera lucida and signed L.B.
Bull's ability to observe and draw is evident in these illustrations and indicate the talent that was to blossom much later when he renewed his interest in sketching and painting in his retirement. Evidently he stayed on at the University Veterinary Institute as a research student, or assistant, during the first 9 months of 1912, because he published a paper on tuberculosis in dogs, based on work carried out at the Melbourne Veterinary School.
The first bacteriological work in South Australia was carried out at the Adelaide Children's Hospital by Dr Thomas Borwick aided by a Sister Dorman in 1884. The earliest reference to bacteriology as an aid in diagnosis at the Royal Adelaide Hospital is 1898, when the Commissioners of that Hospital agreed to a recommendation of the Hospital Board to provide funds for the erection of a small building to house a bacteriology laboratory on the ground floor, and rooms for nurses working in the isolation wards of the Hospital on the floor above. It was not until 1902 that the bacteriology laboratory was fully functional when Dr Borwick was appointed Honorary Bacteriologist to the Royal Adelaide Hospital. Extensions were added in 1910 and this building then became the Government Laboratory for Bacteriology and Pathology and functioned as such until it was absorbed into the Institute of Medical and Veterinary Science on July 1, 1938 (1).
It was to this newly created Government Laboratory of Bacteriology and Pathology that Mr Lionel Batley Bull, B.V.Sc. came at the age of 23 years as First Assistant to the Director Dr C.T.C. de Crespigny. Bull had received a very sound training in both pathology and bacteriology from Professor Gilruth, and he assumed most of the responsibility for the bacteriological work in his new post, as well as becoming involved with human clinical pathology. Characteristically, his first paper on work carried out in Adelaide concerned a disease of economic importance to primary industry interests, i.e. 'Isle of Wight' disease of bees, which had been shown earlier to be caused by the protozoan parasite Nosema apis. In this short paper Bull describes how he identified the cause of the disease, its likely incidence in infected hives, the method of spread within and between hives, and the classical veterinary method of dealing with a highly infectious disease for which no therapeutic measures were available, namely destruction by fire of infected units, and quarantine of the infected 'premises' until restocking had shown the disease to be eradicated.
During the period 1912 to 1934, Bull published 33 papers on work carried out at the Government Laboratory of Bacteriology and Pathology. Ten of these papers were on medical bacteriology or pathology, and 23 papers on veterinary aspects of these disciplines. Three of the 33 papers involved comparative aspects of both human and veterinary medicine. He subsequently published two more papers in 1935 on work he had carried out while in his Adelaide post. Therefore, in the 22 years of work in Adelaide, he published 35 papers. But more than this, he had earned for himself a high reputation as a bacteriologist and comparative pathologist. He was appointed a lecturer in Bacteriology in the University of Adelaide from 1930-33 giving lectures to medical and dental students.
Three other aspects of Bull's Adelaide period need to be considered.
On April 16, 1920, 23 South Australian scientists interested in the medical sciences gathered together in Adelaide to found the Medical Sciences Club of South Australia, and Dr Bull was one of these. This Club has met continuously since that time. It is one of the oldest scientific clubs in Australia, and has served as a training ground in lecturing for many young Adelaide research workers.
Dr Bull held various offices during the years he was associated with the Club, including Councillor in 1923, 1924, 1928, 1931 and 1932, and he was President of the Club in 1926 and 1927. In 1959 he was elected an Honorary Life Member, and in his letter of acceptance to the Honorary Secretary of that time he wrote, inter alia: 'I feel deeply honoured by this action of the Club, since I had many happy and profitable years closely associated with it. The meetings and activities of the Club helped me considerably in those early years'.
In 1924 the Australian Journal of Experimental Biology and Medical Science was launched by the Medical Sciences Club, and was managed by a Committee of the Club on behalf of the University of Adelaide acting as publishers. Bull was one of the 17 original members of the Editorial Advisory Board and remained on the Board continuously until 1952.
The Australian Veterinary Association was inaugurated at a meeting held in Melbourne on February 12, 1921. As early as 1882 efforts had been made by Dr W.T. Kendall to unite veterinarians in Australia into a professional association. By 1894, the Veterinary Medical Association of N.S.W. was established, and similar small associations of veterinarians were formed in other Australian States. It was not until after the 1914-18 War that efforts were made to form a truly national Veterinary Association.
The first President elected in 1921 was Professor J.D. Stewart, Dean of the Veterinary Faculty in the University of Sydney. The actual foundation Members of the Australian Veterinary Association (AVA) are not listed in its records, but there can be little doubt that Dr Bull would have been one of the 10 South Australian financial members referred to in the report of the Honorary Treasurer for 1921-22. At the Council Meeting of the AVA, held on August 16, 1923 in Melbourne, Dr Bull was elected the Second President of the Association. He gave his Presidential address at the Fourth General Meeting held at the University of Adelaide on August 28, 1924. In this address, published in the Journal of the Australian Veterinary Association Vol. 1. pages 10-12, March, 1925, Bull gave a very thoughtful address to his professional colleagues, many aspects of which are still applicable today. He began by declaring, '...I value the fact that I am a graduate of veterinary science, and that I belong to the profession which has much important work to perform in the interests of the development of Australia.' He went on to urge his colleagues to have a deep love for their profession, a keen and enquiring attitude to research, and great vigilance to guard Australia from the introduction of 'serious animal plagues from overseas'. He decried the lack of unity in the profession and called for some measure of publicity to educate the community concerning the role of the veterinarian in animal health and production matters. While praising the recent establishment of Veterinary Schools in both Melbourne and Sydney, Bull called for the establishment of 'special courses of study for a diploma in preventive medicine'. Lastly he urged his field colleagues to seek the help of laboratory veterinarians who should always be ready to go into the field to consult on problems with their practitioner colleagues. All these points are just as valid today as they were in 1924.
It was during this period in Adelaide that in 1925 the Journal of the Australian Veterinary Association was launched. It later became the Australian Veterinary Journal (AVJ) and uninterrupted publication has continued ever since. Dr Lionel Bull is recorded as being largely responsible for the establishment of the AVJ in 1925 (2).
The third aspect of Bull's Adelaide period relates to the part he played in planning the establishment of the Institute of Medical and Veterinary Science (IMVS), which took the place of the old Government Laboratory of Bacteriology and Pathology in 1938. In the first volume of the collected papers of the IMVS there is an account of the history of the establishment of that Institute. It appears that in 1932-34 there was an urgent need to extend the facilities and functions of the diagnostic laboratories of the Adelaide Hospital, which has responsibilities for bacteriological and pathological investigations for other Government Departments, Board of Health, and private medical and veterinary practitioners. Sir Charles Martin, who had been Director of the Lister Institute of Preventive Medicine, London, before he came to Australia to become Chief of the CSIR Division of Animal Nutrition in 1931, jointly with Bull was given the task of drawing up plans for a new building to serve the functions being carried out at that time by the South Australian Government Laboratory of Bacteriology and Pathology. The Martin-Bull plans called for a laboratory to serve the research and routine diagnostic requirements of both the Medical and Veterinary services of the State. Although it was obvious that extensions to the existing laboratory and other facilities were urgently needed, the South Australian Government of the day shelved these plans because of lack of finance.
In 1935, the University of Adelaide Medical School in its jubilee year, received handsome bequests from Miss Edith Bonython, Mr T.E. Barr-Smith and Mr Norman Darling who each gave £5000 for the purpose of medical research, and it was decided to use this money to found an Institute of Medical Research. The South Australian Government agreed to provide a further £15,000 on the understanding that the new Institute would provide accommodation for the routine bacteriological and pathological services of the Adelaide Hospital and the Veterinary Services of the Department of Agriculture.
The Government of South Australia, by Act of Parliament, created the Institute of Medical and Veterinary Sciences (IMVS) on July 1, 1937. It was to be governed by a Council of six representing the Board of the Adelaide Hospital, the University of Adelaide and the Veterinary interests of the State. By this time Bull and Sir Charles Martin had both left Adelaide, but concepts embodied in their original plans for a Laboratory of Comparative Bacteriology and Pathology had actually come to fruition. The concept was brilliant; it is a matter for regret that the high hopes which attended the founding of the IMVS were not fully realized over the succeeding years. While functioning as a very efficient routine diagnostic medical laboratory, the research output, particularly on the veterinary side, generally did not reach the hopes of those who formulated the idea of an Institute of Medical and Veterinary Science. Recently an enquiry was undertaken into the functions of the Veterinary Sections of IMVS in relationship to the requirement for the veterinary diagnostic and research requirements of South Australia. These sections have now been placed under the control of the State Department of Agriculture and it remains to be seen whether this will have any advantage over the previous arrangements.
When the Council for Scientific and Industrial Research (CSIR) was established in 1926 to undertake research for the benefit of Australia's primary and secondary industries the Council decided to concentrate, in the first instance, on primary industry problems. One of the first Divisions to be established was the Division of Animal Nutrition in Adelaide, in 1927, with Professor Thorburn Brailsford Robertson as Chief. When he died suddenly from an attack of pneumonia in January 1930, he was succeeded by Sir Charles Martin who came to Adelaide from London. Like Robertson, Martin was appointed Professor of Physiology and Biochemistry in the University of Adelaide and Chief of the CSIR Division of Animal Nutrition.
The CSIR Division of Animal Health may be said to have had its origin at the first meeting of the Council for Scientific and Industrial Research at which it was decided that efforts should be concentrated on the organisation of research work in five areas of which the first was 'Animal Pests and Diseases' (CSIR Annual Report, 1927). At that time CSIR had no accommodation of its own for animal health research, and the records reveal that Professor Clunies Ross was being accommodated at the University of Sydney, and T.S. Gregory at the Melbourne University Veterinary School. Moreover, the records of the IMVS show that in 1926 the CSIR allocated the sum of £500 for investigation of Stock Diseases at the Government Laboratory of Bacteriology and Pathology, by Dr Lionel Bull. Bull became an officer of CSIR early in 1934 as Deputy Chief of the Division of Animal Health, and almost immediately he was sent overseas on an extended visit to the United Kingdom, Europe and the USA. He did not return to Australia until June, 1935.
Correspondence between Sir David Rivett, the Chief Executive Officer of CSIR, and overseas scientists and administrators arranging for Bull to make contact with the leading research institutes reveal that he was considered at that time to be the leading veterinary scientist in Australia.
Dr J.A. Gilruth was appointed Acting Chief of a Division of Animal Health on January 15, 1930. He served with this status until January 14, 1934 when he became Chief of the Division and served in this capacity until June 30, 1935 when Bull became Chief of the Division. An appeal for funds for capital expenditure was made to members of the animal industries to finance the building of an animal health laboratory in 1929. The only person to respond was Sir Frederick McMaster, a New South Wales grazier, who provided the capital sum of £20,000 for the building of the F.D. McMaster Animal Health Laboratory in the grounds of the Sydney University alongside the Veterinary School. This laboratory was opened on July 1, 1931 with Ian Clunies Ross as Officer-in-Charge. In 1956, Sir Frederick McMaster very generously made available a further substantial sum of money to provide another wing in memory of Captain Ian McMaster who had been killed at the battle of El Alamein (3). The main thrust of the work at the McMaster Laboratory was on studies of intestinal helminth parasites of sheep, although some investigations of bacterial diseases e.g. foot rot in sheep was carried out there from the earliest times.
In 1935-36 the Commonwealth Government provided £20,000 for a laboratory to be built at Parkville, Victoria 'for investigations into mastitis and other animal health problems affecting cattle'. The laboratories were opened in 1938 as a centre of research on bovine mastitis and contagious bovine pleuropneumonia with a graduate staff of eight. Dr Bull made this laboratory the headquarters of his Division. The files and correspondence show that although Dr A.W. Turner was named as the Officer-in-Charge of this laboratory, Dr Bull regarded it as his laboratory, and some uneasiness continued over many years between Dr Bull and Dr Turner over the administration of this laboratory. This unfortunate situation appeared not to have affected Bull's determination to carry out the work which he believed he had been appointed to do. Bull admired Turner's contribution to the work on anaerobic infections of sheep and cattle, as well as his work on contagious bovine pleuropneumonia, but he continued, to the time of his retirement as Chief, to regard the Parkville Laboratory as his laboratory, and to give advice and to issue instructions and directives to the staff, often without any prior consultation with his Offficer-in-Charge.
Soon after the appointment of Bull as Chief of the Division of Animal Health, the Division of Animal Nutrition, which had been established with Professor Brailsford Robertson as Chief in 1927, was absorbed into the newly created Division of Animal Health and Nutrition with Bull as chief and H.R Marston as Officer-in-Charge of the Nutrition Laboratory in Adelaide. Almost from the first, friction developed between Marston and Bull. Marston was a brilliant scientist and this was recognized by Sir Charles Martin and Sir David Rivett, but he appears to have lacked leadership ability because he needed to hold centre stage at all times. He was particularly suspicious of veterinarians, believing their training hardly fitted them for fundamental research. Bull, for his part, required Marston to relate his often extravagant approaches to basic research to problems in the field. The exchanges of letters between these two are models of politeness and reasoned argument on both sides, but under all this can be detected a sense of frustration for both parties; for Marston because he believed he was in the better position to direct the work of his laboratory, and for Bull because he believed that unless Marston was prepared to fully inform and consult him on the general direction of the work of the Nutrition Laboratory, then the Chief could not discharge his duty to the Executive properly. The outcome of this controversy was that, at a Conference of leaders of the Division of Animal Health held March 20, 1944, the Chief Executive Officer of CSIR announced the decision to create a Division of Biochemistry 'with strong and vital contacts with Animal Health, with Plant Industry and with Industrial Chemistry and to less extent with Soils' (C.S.I.R.O. Archives Series 9 A23/5/ (28)). This action was taken against the advice of Bull, and much correspondence ensued about the naming of the new Division which eventually became the Division of Biochemistry and General Nutrition with H.R. Marston as its Chief. It is clear that Rivett believed Marston, once released of veterinary direction, would be able to make more fundamental contributions to scientific knowledge. It is also obvious that Bull believed that the solution of problems of immediate application to the livestock industries should have first priority in matters of research on Animal Health and Production. It is for graziers, cattlemen and economists to judge the relative contributions of the Division of Biochemistry and General Nutrition under Marston, and the Division of Animal Health and Production under Bull, to the livestock industries and the economy of Australia.
Bull's truncated division was renamed the Division of Animal Health and Production on August 18, 1944, and over the next 10 years Bull set about an expanded programme of work involving the establishment of sections on animal breeding and genetics, animal physiology and investigations into ecto and endo parasites of cattle in tropical Australia. It is interesting to note from CSIRO Archives (Series 9 A23/5/28) that in December 1945 Bull outlined a scheme for dividing his Division of Animal Health and Production into a Division of Animal Health and a Division of Animal Production. While the changes that were made in 1959 (five years after Bull retired) resulted in the creation of the Division of Animal Genetics and the Division of Animal Physiology, it was not until 1975 that a Division of Animal Production was created in CSIRO.
These will be considered under seven headings.
As already mentioned, Bull's first scientific paper, of which he was a co-author with Professor J.A. Gilruth, was on neosporidia in native animals. This work arose out of the routine postmortem examinations at the Melbourne University Veterinary Research Institute on animals that had died at the Zoological Gardens, Melbourne. His next studies of parasitology formed the basis for his D.V.Sc. thesis on the nature and distribution of a granuloma of horses caused by invasion of the tissues by the larval stage of nematodes of the genus Habronema. His first paper on this subject described the pathology of a granulomatous condition of the horse and the demonstration of parasitic larvae in the lesions. This paper really confirmed an earlier observation by Rulliet who had suggested that Summer sores in horses were the result of invasion of the tissues by Habronema larvae. In his second and much longer paper on this subject, Bull demonstrated by a series of elegant experiments, involving the introduction of proboscides of flies carrying Habronema larvae into small incisions in the skin, that characteristic cutaneous granulomas could be produced. The tumour produced presented a characteristic macroscopic and microscopic appearance, and Bull produced evidence to suggest that the larvae of the nematodes Habronema muscae, H.megastoma and H.microstoma could possibly produce tumours, and that larvae of H.megastoma were the most likely cause of these tumours in Australian horses. In a later publication, Bull describes how he had an opportunity to study a small tumour from the conjunctiva of a boy aged 13 months suffering from what was known as 'Bung Eye' in South Australia. He produced strong evidence to suggest that this condition in human beings has a similar aetiology to Habronema Granulomas in horses. It may be significant that with the reduction in the horse population, the incidence of 'Bung Eye' in human beings has declined to a point where it is now almost unknown.
The other area of parasitology with which Bull was directly concerned was the vexed question of blowfly strike of sheep in Australia. As early as 1930, CSIR and the New South Wales Department of Agriculture had begun to investigate the prevention and treatment of Blowfly Strike in Sheep. Dr Bull's first paper on this subject was published in 1931 while he was still in Adelaide.
This paper, in addition to describing some of the pathology of the skin in the pre-fly strike dermatitis caused by wetting or soiling of the wool and skin with urine and faeces, details the operation which became known as 'Mulesing of Sheep'. It is significant that in this first paper, Bull recognised the possible part played by Pseudomonas spp. and other skin organisms in preparing the site for fly strike, a subject which is still being investigated by some workers on myiasis of sheep. The CSIRO took up the problem of Blowfly strike in 1932, and appointed a Joint Blowfly Committee consisting of representatives of the N.S.W. Department of Agriculture as well as officers of the CSIR Division of Economic Entomology. This committee reported in 1933. Soon after his appointment to CSIR, Bull became Chairman of this committee and a wide ranging investigation of the problem was undertaken. Bull's committee reported (Report No. 2, in 1940), and their conclusions largely remained the basis of the control of myiasis for many years. The Committee reported again in 1943, but the introduction of the chlorinated hydrocarbons, and other chemical insecticides, tended to lessen the drive for research in Australia on blowfly strike until resistant flies were detected. Now, some thirty years later, work has been taken up again by CSIRO and others in an effort to protect sheep against the loss and misery of blowfly strike. Some of this work, if successful, will trace its origin back to the original observations by Bull on the early lesion of the skin that provides an attractive site for ovi-positing by the sheep blowflies Lucilia cuprina and L.sericata.
Twenty-four of Bull's 88 publications can be classified as contributions to bacteriology. His first paper involving this discipline describes observations he made on tuberculosis in dogs while working as a research scholar at the Melbourne University Veterinary School. This paper, published early in 1914, records a detailed and thorough description of two cases of generalised tuberculosis with ascites, hydrothorax and hydropericardium which clinically presented as malignancies in the dogs. Bull isolated and demonstrated the infectious cause of the condition by experimental inoculation of guinea-pigs and dogs and advised his readers to consider a diagnosis of tuberculosis in similar cases and to inoculate guinea-pigs intraperitoneally with deposit from ascitic fluid to confirm the diagnosis. It is interesting to note, however, that at this stage he was prepared to declare that the tubercle bacilli he demonstrated by staining smears from affected lymph nodes of his animals were tubercle bacilli of the human type. The differentiation of human and bovine Mycobacterium tuberculosis by inoculation of rabbits and guinea-pigs had been defined by the English Royal Commission on Tuberculosis in their reports of 1911 and 1913. However, he was a graduate of only 2 years standing in 1914, and had still to develop into the avid reader of scientific literature that characterised his later development.
His next two papers on tuberculosis were review articles on the standardization of tuberculin for use in animal practice and on comparative aspects of tuberculosis in lower animals. The last paper he wrote on this subject was a preliminary note on the complement fixation test as an aid to diagnosis in the eradication of tuberculosis in cattle. This paper contained little technical detail and embodied results on relatively few sera examined by the complement fixation test by his colleague A.D. Campbell as part of the work being carried out in the Division of Animal Health for the Tuberculin Committee of the Australian Veterinary Association of which Bull was a member. It is interesting that in 1983 bovine tuberculosis has been eradicated from most dairy and beef herds in Australia, and that improved, standardized tuberculin, has played an important part in the achieving of this result.
The next bacteriological contribution by Bull we should consider is to botulism. Although he only published one paper on this subject, he studied so-called forage poisoning in horses and cattle in South Australia for about eight years before publishing Bulletin No. 167 of the South Australian Department of Agriculture on this subject. Although he did not succeed in showing conclusively that Clostridium botulinum toxin was responsible for the condition investigated, he obtained suggestive evidence in this direction. Others later took up this work and identified the various types of toxin produced by Cl.botulinum and showed how to protect animals with a toxoid preparation (4).
A number of corynebacteria are known to be associated with disease in domestic animals. In 1924 Bull published a description of corynebacterial pyaemia in a foal. He isolated a diphtheroid organism with the characteristics of C.equi, an organism which had been described as causing a specific infectious pneumonia of foals in Sweden (5). The condition known as caseous lymphadenitis or 'cheesy gland' of sheep was probably introduced into Australia with merino sheep since its incidence in England is low and British breeds of sheep in Australia appear to be somewhat less susceptible than merino or crossbred sheep (6). Caseous lymphadenitis is caused by infection with Corynebacterium ovis, sometimes called the Preisz-Nocard organism or Corynebacterium pseudotuberculosis ovis. Abattoir meat inspection figures would seem to indicate an incidence of the disease of between 2 and 99 percent depending on the age and breeding of the sheep. This incidence has not changed very much over the last 80 years. As part of a larger programme designed to study sheep diseases in Australia, Bull, with the collaboration of C.G. Dickinson, a veterinary graduate employed as a research scientist by the Animal Health Division of CSIR, commenced a study of caseous lymphadenitis about 1930. They published six papers between 1931 and 1935, five with Bull as senior author, and one paper with Dickinson as senior author. These early papers defined methods of growing the organism in the laboratory, and pathogenesis of the disease produced by inoculating guinea-pigs by the cutaneous and sub-cutaneous routes as well as by ingestion. In one paper, they demonstrated the production of a soluble toxin when the organism was grown under suitable laboratory conditions. They showed that the organism could be isolated from the gut and faeces of sheep infected with C.ovis as well as from the faeces of healthy sheep. They also showed that the soil of camp grounds, and of the yards associated with shearing sheds, harboured the organism, although its detection in these situations was variable. On the basis of their observations, they suggested that the wounding of animals, e.g. at shearing, and the infection of these wounds by contaminated shearing equipment, or from the contaminated environment of the yards, provided a possible explanation of the mode of infection of sheep in some instances.
This work by Bull and Dickinson formed the basis of most of the investigational work on the pathogenesis and attempted control of this difficult problem by many other workers over the next 50 years. It is interesting that in 1971 the CSIRO Division of Animal Health instituted a programme 'To examine the pathogenesis of this disease, the immunological reactions to the causal organism, and to explore the possibility of developing a vaccine' (Div. of Animal Health Report 1971). This objective has largely been achieved with the provision of methods for diagnosis of natural infection and assay of serum antibody responses to vaccination, and the preparation of a vaccine optimally effective in producing durable immunity against experimental infection by Burrell (7) at the McMaster Laboratory of the Division. It appears that after all these years an effective method of controlling this difficult field condition is now in sight and is based on the incorporation of both inactivated bacteria and toxin produced by C.ovis in an immunizing preparation as Bull and Dickinson indicated would be necessary in their early papers. The solution to the problem hinged largely on the discovery by Burrell (8) that intralymphatic inoculation of C.ovis induced caseous lymphadenitis in sheep. Prior to this, experimental production of the disease in sheep was difficult and irregular. In the course of his studies on this subject Bull also published a paper describing infection of a cow with C.ovis which is still a relatively rare condition.
Anaerobic infections of sheep and cattle, when not controlled by the appropriate vaccines, are the most common cause of economic wastage due to bacterial infections in the livestock industry. Although Bull only published six papers on this subject himself he influenced a much wider group of veterinary bacteriologists in their thinking and efforts. His classical study of the condition known as 'Swelled Head' or 'Big Head' of young rams in South Australia provided an understanding of the natural history of the disease. He demonstrated that small wounds about the head were produced when rams (particularly young rams) indulged in combat for play or sexual dominance, and these wounds became infected with Clostridium oedematiens (Cl.novyi). We now know that this organism elaborates a phospholipase toxin which has a profound effect on vascular endothelial cells causing leakage of fluid and serum proteins into the tissues. The organism usually remains localized in the infected tissues and hence cultivation of the oedema fluid produces no evidence of its presence. Bull showed that a vaccine composed of toxoid and killed Cl.oedematiens organisms given in two or three doses fully protected rams against Big Head. The vaccine developed by Turner (9) to control Black disease, which is caused by the activation of spores of Cl.oedematiens located in the liver of sheep or cattle when liver fluke (Fasciola hepatica) migrate through the liver producing tissue damage that provides the right respiratory environment for germination, growth, and toxin production of the organism, will also protect sheep against the syndrome of 'Big Head'.
Enterotoxaemia and pulpy kidney disease of lambs is now fairly well controlled by specific vaccines providing antitoxic protection against the epislon toxin elaborated by Clostridium perfringens type D which is produced in the intestine of lambs at or about weaning time. In 1924, Bull described a syndrome of sudden or unexpected death in sheep and lambs that he had been investigating since 1917. The disease resembled the braxy of Europe which had been known from about 1900. He failed to find the actual aetiology of the disease, but from his extensive experimental observations he concluded that it was enterogenous toxaemia due to growth of Clostridium welchii in the gut, a concept which at that time was quite new to veterinary pathology. Later work by H.W. Bennetts (10) followed up Bull's observations and showed that one particular serotype of the organism was responsible for both enterotoxaemia and pulpy kidney disease.
Veterinary bacteriologists in Australia and New Zealand during the early decades of the twentieth century made outstanding contributions to the understanding and control of anaerobic infections and toxaemias of livestock, and Bull was by no means the least of these. In a short monograph published in French, by the Office International des Epizootics in 1930, Bull summarizes his own, and the work of his colleagues on enterotoxaemia of sheep in Australia.
Every bacteriologist hopes to isolate and characterize a previously undescribed organism. In two papers Bull achieved this when he isolated and described Actinomyces dermatonomus as the causal agent of 'lumpy wool' of sheep. The first paper was characteristically a brief report published in The Journal of the Department of Agriculture to reach graziers and extension officers as quickly as possible, while the second paper was a complete description of the morphology and cultural characteristics of the isolated organism published in an international journal, viz, the Australian Journal of Experimental Biology and Medical Science. Subsequent work by D.S. Roberts at the McMaster Laboratory of CSIRO extended our knowledge of the pathogenesis of the agent and the natural history of the condition (11). The name of the organism has been changed to Dermatophilus congalensis, but the priority of discovery of this organism has remained with Bull.
Soon after he became Chief of Division in 1935, Bull was appointed Chairman of a committee organised to investigate bovine mastitis. The other members of the committee were the Director of the Melbourne University Veterinary Research Institute, Dr H.E. Albiston, the Chief Veterinary Officer and Superintendent of Livestock, Victorian Department of Agriculture, Mr R.deC. Talbot, and Dr A.W. Turner, Officer-in-Charge of the CSIR Animal Health Research Laboratory Melbourne. The committee outlined a programme of investigation based on an experimental dairy herd which was set up at Werribee about 30 miles out of Melbourne. They reported the results of their investigations over two lactation periods and concluded that, contrary to the then firmly held view of British and European workers, the infected udder is not the only reservoir of Streptococcus agalactiae. They also drew attention to the seriousness of staphylococcal mastitis when it occurred in their animals. The monograph, reporting on the work of the group under Dr Bull's direction was published in 1940. It recorded a most meticulous study and provided a basis for any further work on this subject. With the advent of penicillin for veterinary purposes in 1945 it appeared that the eradication of mastitis from dairy herds was only a matter of time, and work on this subject was soon abandoned. It is worth noting that mastitis, and particularly staphylococcal mastitis, is still a serious problem for the dairy industry, and that once again a study of it has been instituted by the CSIRO Animal Health Division. This time however, the emphasis is on the mechanism of immunity in the ruminant udder and the possible development of a specific vaccine against staphylococcal mastitis. (Report Division of Animal Health 1979-80). Characteristically Bull published a number of articles in The Australian Dairy Review between 1940 and 1945 during the progress of the research on mastitis in order to keep the industry informed, and the series published in 1945 outlined husbandry and hygiene techniques for prevention, as well as the use of antibiotics for the control of outbreaks of the disease.
Soon after taking up duty in the South Australian Government Laboratory of Bacteriology and Pathology, Bull published a report of a study of 17 isolations of Friedländer's bacillus from clinical cases of atrophic rhinitis or ozaena in human beings. This paper formed part of the Transactions of the Australian Medical Congress held in Auckland in 1914. This would be one of the earliest studies of this organism in relationship to atrophic rhinitis of human beings with an analysis of variation in the fermentation of sugars by isolates. It is interesting to note that Bull concluded that Friedländer's bacillus probably plays only a secondary role in the condition since we now know that atrophic rhinitis of pigs is caused primarily by infection with a cytomegalovirus (herpesvirus) and that a variety of bacteria are associated as secondary invaders in this condition in pigs. It says something for Bull's scientific instinct at this early stage in his career that he was not convinced, on the evidence before him, that the bacillus he had isolated was the primary cause of the clinical condition of the human patients from whom he had made the isolations.
In 1918 Bull published a short account of 'Impetigo of the pig'. He gave a careful description of the occurrence, age incidence and clinical signs of the disease as he had seen it over a period of two years in South Australia. He also carried out experimental infection of pigs by transferring lice (Haematopinus suis) from infected to clean young pigs, and also by inoculating the scarified skin of a pig with lesion material from affected pigs. In both experiments he succeeded in reproducing the vesicular lesion in his animal but with an incubation period of 7-10 days for the appearance of lesions. Despite this long incubation period, Bull concluded that streptococci and staphylococci, which he regularly found in the lesions in the field, were the cause of the disease. Almost certainly this condition was swine pox caused by the swine pox virus, and one of us (ELF) carried out experiments with similar lesion material from pigs in Victoria about 1968 (unpublished data) and isolated a poxvirus which grew in tissue culture of swine testis cells, and which was transferable to pigs by scarification of the skin with tissue cultured virus free of any bacteria. However, the control of lice in piggeries as advocated by Bull in his paper, is an effective method of controlling this disease. Mortality, when it occurs in these cases, is usually caused by concomitant salmonella infection as noted by Bull in his cases.
Bull published one paper on fungal diseases and this was in collaboration with Dr Harry Swift, a physician of the Adelaide Hospital. This paper described a case of torula meningitis (Cryptococcal meningitis) in a 53-year-old male Chinese. It was the first recorded case of its kind in Australia, and Bull correctly identified the yeast he grew from the spinal fluid of the patient although its name has been changed twice since 1917. His description and drawings of the yeast cells are typical of his powers of observation, and the Indian Ink method he used to demonstrate the characteristic capsule of this organism in the CSF is still used today for identifying this rare condition.
The wild European rabbit (Oryctolagus cuniculus) was deliberately introduced into Australia in 1859, and within 20 years had become a scourge to land holders. Many methods were tried in efforts to control the pest, but it continued to spread far and wide and to cause loss of pastures and extensive erosion of the land. The disease myxomatosis of European rabbits was first described in 1898 in South America, and around 1927 it was suggested by the virologist Aragao that myxomatosis virus might be used to control the rabbit plague in Australia. A limited trial was made in NSW by White in 1928 but was not pursued.
One of the problems taken up in 1934 by CSIR was the control of rabbits to attempt to ease the burden on graziers caused by the ravages of these animals. Sir Charles Martin was asked to investigate the possibility of using the myxoma virus as a biological method of controlling rabbits. He began his investigation at the Institute of Animal Pathology, University of Cambridge, England in 1934 and reported his findings in 1936 (12). Bull, while on his visit to England and Europe in 1935, had the opportunity of observing these experiments, and on his return to Australia he undertook a programme of work to determine whether native and domestic Australian animals could be infected with the myxomatosis virus. In the course of this work, he discovered the experimental transmission of myxoma virus by insect vectors, viz; fleas and mosquitoes. He and his colleague, Mr Bill Mules, undertook the first field trials with the virus in 1937 on Wardang Island in Spencer Gulf off the coast of South Australia, and at Point Pearce on the mainland of South Australia. The results were almost a complete failure. There was only limited spread of infection with many fully susceptible rabbits being left in the warrens of the area. However, when rabbits were infected with the rabbit flea, Echidnophaga myrmecobii, the disease appeared to be more effective within the warrens, but did not spread to adjacent warrens. Bull and Mules concluded that 'myxomatosis cannot be used to control rabbit populations under most natural conditions in Australia...'. They further commented 'Nevertheless, it seems possible that in some parts of Australia under special conditions, including the presence of insect vectors in abundance, the disease could be used with some promise of temporary control of a rabbit population, and to be of any real value the disease would have to be used when the rabbit population density was moderate...and a reintroduction would be necessary from time to time...'. They were refused permission to conduct further experiments in well-watered parts of Australia where mosquito or other winged vectors of the virus could be expected to be present in large numbers.
During the war years of 1939-45, rabbit populations grew to real plague proportions in many regions of Australia. Something had to be done about this predatory pest. There was much clamour from the graziers, and some professional people, for the Government to allow widespread dissemination of myxoma virus. By this time Bull had his Division fully engaged on other work, but he entered the controversy to caution against the clamour to allow the indiscriminate use of myxoma virus by lay people before the critical experiments had been carried out to determine all the factors involved in the spread of the virus and its effect on rabbits under field conditions. His principal opponent was the redoubtable Dame Jean Macnamara, a physician who had worked with Burnet on poliomyelitis some years before. She saw Bull's stand as obstructionist, but failed to appreciate that he was approaching the problem from a sound scientific basis. Probably the controversy made it easier for the Wildlife section of CSIRO to obtain permission from the Director General of Health to carry out field trials with myxomatosis in the higher rainfall area. These experiments were begun in May 1950 and after what appeared to be another failure, the disease spread rapidly in December, and by March 1951 millions of rabbits had been destroyed (13). Subsequent work by Fenner, Ratcliffe, Douglas and others in Victoria and New South Wales, confirmed the predictions of Bull and Mules in 1944 regarding yearly seeding of the rabbit populations for effective control. The benefit of the work, began by Bull in 1935, on the control of rabbits by myxomatosis has been calculated in thousands of millions of dollars in increased productivity in the sheep and wool industry, as well as in saving millions of acres of good land from erosion.
The other virus disease with which Bull was directly associated was scrapie. This we now recognize as one of the so-called slow virus infections, and it is the veterinary analogue of the human spongiform encephalopathies, Creutzfeld-Jakob Disease and Kuru. The latter is the 'laughing disease' of the Fore people of Papua-New Guinea.
Scrapie has been recognized as a chronic, fatal ataxia of sheep and goats in England and continental Europe for more than two centuries. It affects some breeds more frequently than others, the Suffolk breed being particularly susceptible. In 1951, after quarantine, a small consignment of one ram and nine Suffolk ewes were imported into Victoria from the United Kingdom. About a year later, one of the imported ewes died of an unidentified neurological condition and two other imported ewes showed signs of intense pruritis. The owner sought the advice of his veterinarian who, in turn, called Lionel Bull for a consultation. After taking a careful history, making a complete clinical examination, and carrying out an autopsy on one of the affected ewes, Bull had no hesitation in making a diagnosis of scrapie. This diagnosis was never confirmed either histopathologically or by transmission experiments. On being informed of the clinical diagnosis, the Victorian Chief Veterinary Officer ordered the destruction of all the remaining imported sheep and the incontact sheep, and placed the property in quarantine. The remaining sheep that had no contact remained in good health over the next six years after which time the property was released from quarantine. The incident has been recorded as an outbreak of scrapie in Australia that was eradicated by slaughter and quarantine. It provided a lesson for present-day veterinarians in the value of calling in consultation a professional colleague with specialized knowledge of exotic or other diseases when confronted with a difficult clinical problern.
This is probably the place to deal with Bull's contributions to the diagnosis and control of exotic diseases in Australia. The Conference of Commonwealth and State Veterinarians was first convened by the Australian Agricultural Council in 1941. At this meeting, Dr Bull warned those attending of the need for a rapid and accurate diagnosis should an exotic disease enter Australia. He became Chairman of the Foot-and-Mouth Disease Diagnostic Committee which drew up plans for handling an outbreak of this disease. These early stirrings, initiated by Dr Bull, were followed in 1958 by the establishment of a virology section under one of us (ELF) in the Animal Health Division of CSIRO, which led eventually to the establishment of the Australian National Animal Health Laboratory (ANAHL) being built at Geelong, Victoria. This high security laboratory was expected to be functional about 1984 or 1985, and, although he retired as Chief of the Division in 1954, the concept of ANAHL, or something like it, was implicit quite early in Dr Bull's writings and comments.
The papers in this area cover a period from 1914 to 1939. The earlier of them make interesting reading in that they show how a veterinary pathologist and bacteriologist developed competence and excellence in dealing with human diseases and disease processes. In the first of these papers with his Director, Dr C.T.C. de Crespigny, on 'Primary enlargement of the Spleen', he was the junior author largely with responsibility for the clinical pathology and laboratory observations. Some of the others, like 'A note on the bacteriology of Hodgkin's Disease' and 'Rickets in foxhound puppies', illustrate the state of knowledge of these conditions at that time. Bull's description of the clinical and experimental investigation of rickets in foxhound puppies appeared some four years before the classical studies of Mellanby and of McCollum describing the antirachitic effects of the vitamin D component of cod liver oil. Although Bull was aware at this time of Bland-Sutton's experimental prevention of rickets in lion cubs in the London Zoo around 1917, he concluded 'that the disease in puppies was due to a gastrointestinal intoxication'! Then followed four papers which illustrated Bull's increasing confidence in his function as a pathologist, and his contribution to clinical pathology. He described the use of the Proteus Xl9 agglutination test for the detection of patients suffering from typhus – the so called Weil-Felix reaction – which was introduced in Germany in 1916 for the diagnosis of endemic typhus fever. Dr F.S. Hone, a senior physician in Adelaide clinically identified cases of murine typhus mainly in dock workers in Adelaide in 1922, and Bull introduced the Weil-Felix agglutination test into the hospital laboratory to aid the recognition of these cases at about this time. Bull was involved in two papers read to the Australian Medical Congress in 1926. The first of these with Professor J.B. Cleland dealt with the clinical and gross pathology of 'the anaemias, leucaemias, leucosarcomas and allied conditions'. The other paper was a plea for more attention to comparative pathology in relation to human disease. Bull outlined several areas of animal disease and microbiology that could assist in the understanding of human disease, viz, the toxaemias of pregnancy, milk fever in cattle, clostridial infections and toxaemias, e.g. botulism, and he concluded with reference to Habronema granulomas in horses and human beings. With Dr B.S. Hanson, a radiotherapist and cancer specialist, Bull published a paper on 'Pathology in its relationship to Diagnosis and Treatment of Cancer...' which was read at the Fourth Australian Cancer Conference held in Canberra in 1933. Bull was responsible for the section of this paper dealing with the pathology of biopsy specimens taken both ante and post mortem from the series of patients reviewed.
The Second International Congress for Microbiology was held in London, England in 1936. Although he was unable to attend, Bull had a paper presented on his behalf by Dr G.F. Petrie of Elstree, England. This paper outlined Bull's work on the Preisz-Nocard bacillus, and his evidence that antitoxic immunity may not protect against infection, but often greatly reduced the severity of the morbid process which is often all that is necessary in prophylaxis of some bacterial infections. At the Canberra meeting of ANZAAS in 1939, Bull gave the Presidential Address to Section L – Veterinary Science. He chose as his subject, 'Some Modern Trends in the Study of Host-Parasite Relationship in Animal Diseases'. This paper expanded ideas he had expressed in an earlier communication which he had prepared as a discussion paper for Dr Gilruth. In his Presidential address, Bull dealt in detail with work being carried out in England by Topley and Greenwood and by Webster in the USA. These workers studied the course of a Salmonella infection and of the virus infection, ectromelia, respectively in a colony of mice to which fully susceptible animals were regularly added. Using the results of these experiments, Bull showed how a number of conclusions about the epidemiology and natural history of an infectious disease could be defined. He outlined similar work being undertaken by Campbell et al (14) with bovine pleuropneumonia in the CSIR Animal Health Laboratory at Townsville in Queensland. This lecture was an attempt to discuss host-parasite relationships, and the effect of a number of environmental factors on these relationships, in order to throw more light on the course of infectious diseases in communities of human beings and animals. It was a scholarly address and concluded on this note:
The experimental method cannot stand alone, but must always be complementary to the wider study of host-parasite relationships under natural conditions. The veterinarian is particularly fortunate in being in a position to apply the experimental method more or less directly to the herd. As a result, his observations can be more direct, and his conclusions sounder, than would be the case if he were forced to draw them from analogy.
This lecture began with a tribute to his old veterinary teacher, William Tyson Kendall, and concluded with a clarion call to his veterinary colleagues to put their particular knowledge, skills and opportunities to work to solve the problems of infectious diseases of man and animals.
Bull appears to have had an interest, quite early in his career, in the plant poisons affecting livestock. His first paper in this general area was published in 1929 on the poisoning of sheep by Soursobs (Oxalis cernua), a weed which grows profusely for three to four months of the year, overcrowding other pasture plants, in southern Australia. His detailed description of the ataxia, tetany, nephritis, and blood chemistry seen in this condition provided the first description of poisoning of livestock by this plant. A little earlier he had discussed the occurrence of photosensitization in sheep fed on various clovers, and the part the photodynamic action of light plays in the aetiology of the dermatitis that is produced.
His next excursion into this area was an investigation of bovine enzootic haematuria. Haematuria, or 'Red Water' in cattle, occurs in many countries. Three possible syndromes are recognized, viz; post parturient haemaglobinuria, nutritional or kale haemaglobinuria, and enzootic haematuria. The precise causes of these syndromes are still not well understood. With Dickinson and later with Dann, Bull investigated enzootic haematuria which involved some very careful histopathology of the lesions in the bladder of the affected cows, as well as some blood chemistry which did not throw much light on the aetiology of the condition. It is interesting that Bull and his colleagues noted the extensive occurrence of ferns and bracken in the pastures on some affected unimproved properties, but they did not suspect these to be of any significance. Pamukcu et al (15) produced haemangiomas and carcinomas indistinguishable from those seen in classical enzootic haematuria by feeding cattle low levels of bracken fern over relatively long periods. In New Zealand, Smith and Beaton (16) claim to have confirmed earlier work by allowing cattle access over a long period to low intakes of bracken. It now seems likely that enzootic haematuria is caused by the ingestion, over a long period, of a substance present in bracken fern that has a radiomimetic effect on the bladder mucosa of cattle, giving rise to the full range of clinico-pathological signs characterising this disease. While Bull and his colleagues concentrated more on the blood chemistry and mineral metabolism of their cases, the careful clinical and pathological observations they made paved the way for later work by others.
Work on ataxia of sheep was carried out in 1938 as part of Bull's association with H.R. Marston. For many years in southeastern South Australia, a condition known as enzootic marasmus or 'coast disease' had been recognized. Large areas of land with adequate rainfall were quite unsuitable for grazing animals. The elucidation of the part played by copper, cobalt, molybdenum and sulphate in this and other metabolic diseases of ruminants is a fascinating story, in which Bull and his co-workers played no small part in unravelling the many tangled threads and leads uncovered by their own and the work of others. Essentially the CSIR contribution to the study of Coast Disease of Sheep in South Australia was led by Marston and his staff in Adelaide. The identification of cobalt and copper as essential elements in the metabolism of the ruminant animal is usually attributed to Marston, but Bull always maintained that the careful, painstaking contributions of Underwood and Filmer in Western Australia to this problem, did not receive the credit it deserved. For his own part, Bull took a particular interest in the Ataxia of young lambs which appeared sometimes, but not always to be associated with 'coasty' districts. He defined the essential demyelinating lesion of the spinal cord of animals affected by this condition and related it to the 'sway back' syndrome of lambs described by others in the border districts of England and Scotland. The credit for defining copper deficiency as the primary cause of enzootic ataxia of lambs must go to Bennetts and Chapman (17). Bull acknowledges this and he was able to quickly confirm the results of the Western Australian workers by the use of 'copper licks' on affected properties.
The subsequent unravelling by Bull and others of the part played by copper (deficiency and excess) in the metabolism of ruminants can now be considered. From about 1926, graziers had suffered losses of sheep from a condition which they called 'yellows' and which veterinarians recognized as a haemolytic jaundice with intense anaemia. The disease appeared to be confined to British breeds of sheep or their crosses and to occur in certain defined districts. It became known as toxaemic or enzootic jaundice. The story of the investigations of toxaemic jaundice and its relationship to chronic copper poisoning and pyrrolizidine alkaloidosis is well documented in the review article published by Bull in 1964. It was in 1938 that a cooperative investigation, involving CSIR, the University of Melbourne Veterinary Research Institute and the Departments of Agriculture of Victoria and N.S.W., was set up with Bull as Chairman. Bull and Dick had already confirmed Boughton and Hardy's (18) observation that copper was involved in enzootic jaundice, and they had shown that there was a sudden and spectacular rise in blood-copper values which heralded the haemolytic crisis of toxaemic jaundice. The hypothesis was developed by the Toxaemic Jaundice Investigation Committee that this condition of sheep was a manifestation of chronic copper poisoning.
Field observations were carried out in N.S.W. and Victoria but most of the experimental work was carried out by A.T. Dick and J.B. Bingley at Bull's Parkville laboratory. The work was pursued with great vigour, and fundamental contributions were made by the team to the understanding of the complex interactions of minerals in the nutrition of sheep. It was found that a small intake of molybdenum decreased the storage of copper in the sheep liver provided there was a sufficient intake of sulphate. In northern Victoria, toxaemic jaundice appeared to be associated with copper accumulation in sheep grazing early-germinated subterranean clover pasture in which molybdenum was virtually absent from the vegetative parts of the plant. This did not explain the occurrence of 'yellows' in sheep in New South Wales grazing on the pastures devoid of clover.
Quite early in the investigation, systematic botanical surveys were made, and the copper and molybdenum contents of various plants were determined. No positive correlation between copper content of the plant species in the pastures and the build-up of copper in the liver was obtained. In the course of this work, it was discovered that feeding the summer-growing pasture plant, Heliotropium europaeum to sheep not only increased blood copper levels and produced some deaths, but it also caused severe and often fatal liver damage in animals grazing this plant over two consecutive seasons. This observation eventually provided an explanation of the differences in the natural history of toxaemic jaundice in Victoria and N.S.W.
It was finally concluded that there are three main types of chronic copper poisoning in sheep. The first is due to the excessive intake of copper, usually as a contaminant of food or pasture. The second type is due to liver damage produced by the consumption of plants containing pyrrolizidine alkaloids. This latter was described as hepatogenous, chronic copper poisoning, and most commonly occurs in British and crossbred sheep in Australia when they graze pastures with H.europaeum. The rise in blood copper in this condition appears to be due to the sudden death of liver cells which are killed through the intracellular release of bound copper which then destroys some enzyme systems in the cell, and copper is washed out into the circulating blood with haemolysis following about 24 hours later. Death of the animal is brought about by anoxia and loss of kidney functions The third type is due to mineral or inorganic imbalance in sheep that have consumed a plant which is low in molybdenum and inorganic sulphate e.g. subterranean clover growing luxuriously in early autumn following rain.
This team investigation is an example of a fundamental study which covered all aspects of an obscure problem which was pursued until a lead appeared. The lead, once uncovered, was explored extensively to achieve an understanding of the basic principles involved. The personal authority and leadership of Dr Bull gave confidence to all involved. But this was only the beginning of what was to be Bull's major work in his last period of scientific effort.
During the investigations, it was found that consumption of another weed, Echium plantagineum (now called Echium lycopsis) (Paterson's curse or Salvation Jane) could predispose sheep to the haemolytic crisis of chronic copper poisoning. This weed, together with Senecio jacobaea (the common ragwort which had been shown to produce chronic copper poisoning in New Zealand), contains hepatotoxic pyrrolizidine alkaloids.
In 1950 Dr Bull became Chairman of another Interstate Committee formed to investigate Kimberley and Birdsville Diseases of horses. Kimberley or 'Walkabout' disease is a problem in stock horses on cattle stations in northern Australia. Some early botanical investigations in the 1920's had led to the suspicion that Crotalaria retusa may be the cause of this disease, but limited feeding experiments had failed to confirm this. Under Bull's direction, feeding trials were undertaken with Atalava hemiglauca (Whitewood), Crotalaria retusa and C.trifoliastrum. Persistence in feeding was considered to be vital, and when material ran out at Katherine, where a trial was being conducted, the animals were transferred to Alice Springs to complete it. Bull had confidence in his own judgement, and this contributed to the successful outcome of the investigation. The horses that consumed large quantities of C.retusa developed the striking signs of 'walkabout' disease. The incrimination was confirmed by the finding of liver pathology with prominent megalocytosis in most cases, and finally by the chemical findings in Melbourne, by collaborators at the CSIRO Division of Industrial Chemistry, that the leaf of this plant contained monocrotaline, an alkaloid already known to be hepatotoxic. It is now known that some other species of Crotalaria may contribute to Kimberley horse disease, but C.retusa appears to be the most potent source of the alkaloid causing this condition.
The greater part of Dr Bull's work on the pyrrolizidine alkaloids was carried out after his retirement as Chief of the Division of Animal Health in 1954. He continued as a Research Fellow until the age of 78. In this period Dr Bull, in collaboration with his two long-time collaborators, Dr C.C.J. Culvenor and Dr A.T. Dick, OBE, FAA, wrote the full account of his work, and that of his colleagues over many years on pyrrolizidine alkaloidosis. This book, The Pyrrolizidine alkaloids – Their chemistry, pathogenicity and other biological properties, was published by North-Holland Publishing Company as No. 9 in their series, 'Frontiers of Biology'. It marks the importance of pyrrolizidine alkaloids among plant poisons in Australia as well as summarising the new knowledge of their pathology, pathogenesis, toxicology and chemistry up to the time Dr Bull retired from active work in this field. In all Bull published, in addition to the above mentioned book, eleven papers on pyrrolizidine alkaloidosis.
In addition to his original contributions to the scientific literature, Bull published a number of general or small review articles. He had a clear style in his writing even in his earlier papers. He possibly became more concise and economic in his reporting, but all his papers are easy to read. It is not surprising, therefore, to find that he was called on to write for a very wide readership. He was particularly successful in writing for the lay press, and could make quite complicated scientific ideas and principles appear simple and easily understood. Some of his writings, directed to his professional colleagues, were direct and did not always find ready acceptance. He always put his argument firmly, but with courtesy, so that he rarely lost friends over such matters.
This group of papers range over articles for farmer-journals to the very interesting summary of 'Some advances in Research on Problems of the Animal Industry in Australia during the last twenty years' published in the Empire Journal of Experimental Agriculture, 1958. While these papers did not report new research findings, they are important contributions to the dissemination of knowledge and illustrate again his concern that the results of scientific research should be used for the benefit of man and animals as early as possible.
Bull received many honours in his long scientific career. He was awarded the degree of DVSc. in 1919. In 1945 he was made an Honorary Member of the Section of Comparative Medicine of the Royal Society of Medicine (London) and in 1949 he was made an Honorary Associate of the Royal College of Veterinary Surgeons (London). In the same year he was elected a Fellow of the Australian Veterinary Association. Her Majesty the Queen created Dr Bull a Commander of the Order of the British Empire in 1952, and he was elected a Fellow of the Australian Academy of Science in 1954. He served the Academy as a Councillor (1959-61) and as Vice-President (1960-61). In the year 1955 he was awarded the Mueller Medal by ANZAAS and the Gilruth Medal by the Australian Veterinary Association in the same year. There can be little doubt that to have his name linked yet again with that of his old teacher, Chief, and friend, would have given Lionel Bull much satisfaction on that occasion. The ANZAAS medal was awarded to Bull in 1967, and in the same year the University of Melbourne conferred on him the degree of Doctor of Laws honoris causa in recognition of his long and distinguished contribution to research and teaching in Veterinary Science and for service to the Veterinary Faculty of the University. The Australian College of Veterinary Scientists was established at an inauguration ceremony in Canberra on May 16, 1971. Dr Bull was elected a Foundation Fellow of the College.
Lionel Bull married Beatrice Johana Reay, daughter of the late Col. W.T. Reay, CBE, in Adelaide in 1913. They had two children; Peter who took a medical degree in Melbourne and was a specialist in diseases of the chest and Director of Tuberculosis in the Victorian Department of Health, and Diana who took a BSc degree from Melbourne University and carried out research with Sir Macfarlane Burnet, FRS, FAA at the Walter and Eliza Hall Institute for two and a half years before she married John Selman, a Victorian grazier. The Selmans provided Dr Bull and his wife with four grandchildren.
Dr and Mrs Bull were music-lovers, being particularly interested in chamber music. They were members of the Musica Viva Society and could be counted on to be at its performances in Melbourne. From remarks made in the 'tea room' of the laboratory in Melbourne, after he had retired as Chief, one gathered that Dr Bull enjoyed the programmes of the radio, but that he disliked television and did not own a TV set. In his younger days Bull was a keen tennis player and was reputed to be 'no slouch with a racquet'. He retained an interest in the game all his life. Reference has been made to his artistic bent as a young research worker and his illustrations of neosporidia in the tissues of native animals. He studied drawing and sketching as a young man with John Mather of Melbourne and with the artist Will Ashton in Adelaide. No doubt the pressure of research tended to restrict his ability to sketch and paint. On his retirement as Chief of the CSIRO Division of Animal Health and Production in 1954, he again took up his interest in painting. He took lessons from the Melbourne artists, Len Annois and Karles Mednis, and was a member of the Victorian Artists Society. He worked with oils and water colour and successfully exhibited his work at a variety of art shows including, on a number of occasions, the Moomba Art Show in Melbourne. He presented examples of his work to the Australian Academy of Science, the CSIRO Animal Health Laboratory, Parkville, and to the Wallaby Club of Victoria. Some friends and acquaintances managed, often with difficulty to persuade him to sell them examples of his work.
On his retirement, the staff of his Division commissioned the portrait artist Murray Griffen to paint a portrait of Dr Bull. Appropriately this painting hangs in the Divisional Conference room of the Parkville Laboratory opposite Sir John Longstaff's portrait of Dr John Anderson Gilruth.
The Wallaby Club of Victoria was first established in 1894 and after a brief lapse was restarted in 1899. Since that date it has met regularly with two annual dinners, organized walks once a fortnight, and longer meetings at Easter and the Melbourne Cup weekend, the latter two with wives of members and overnight accommodation arranged at a suitable boarding house or motel. The members and Past-Presidents of this Club include such distinguished names as Sir John Monash, Sir Owen Dixon, Sir Macfarlane Burnet, and many others who have made notable contributions to Victoria's welfare. Lionel Bull was elected a member in 1935; he served for some years on the Committee and was President for the year 1947. He regularly attended walks until he was about 80 years old and was a favourite of all members. He loved nothing better than a full day of walking, the grilled chop, billy tea and the good fellowship.
During the later years of his membership, when he could not walk so far, he turned up with easel and paint box and would set himself up to paint somewhere near the lunching place and so be present to join in the conversation.
Professor John Turner, FAA, a member of the Club who knew Bull well, writes:
The Wallaby Club of Victoria is not the typical walking club, but rather a social club of men of affairs and the professions, vitally interested in walking in the bushland around Melbourne. In both these aspects of the Club, Lionel Bull took an active part. He was considered to be a mine of information about plants, particularly those that were poisonous for man and domestic animals. He had a love of the Australian bush and landscape which he competently painted in oil or water colour. He and his wife Beatrice regularly attended the Melbourne Cup weekend walks and they were generally regarded as a true blue Wallaby pair.
Bull was active in promoting various aspects of veterinary teaching. He joined the Faculty of Veterinary Science of Melbourne University when he came to Victoria as Chief of the CSIRO Division of Animal Health in 1935, and was a member for thirty years. For many years he also served as a Member of the Faculty of Agriculture in the same University. In the mid forties he was a very active member of the Australian Veterinary Association's Standing Committee on Education. In this capacity he was able to exert some influence on teaching in Australian Veterinary Schools. He was a member of the group of senior people who worked for the reopening of the Melbourne Veterinary School in 1964. In his last published paper Bull gave an account of the development of veterinary science in Australia.
Around the time of his retirement as Chief of the Division in 1954, he was found to be suffering from a degree of hypertension. This was fairly readily brought under control and he continued to come to the laboratory as a Senior Research Fellow for the next 13 years. Sometime after he finally retired from scientific work he suffered a stroke which left him paralysed on the right side of his body. He and Mrs Bull entered a nursing home in Camberwell (Victoria) in 1976 where Mrs Bull died on November 5, 1977 after a long illness. Bull's intellect was not greatly affected by the stroke, and he continued to receive his friends and colleagues in his room at the nursing home, and to take an interest in their work. He would question them carefully and was still quick to pick the weak point in an argument or in an experiment described to him.
He died quietly at Camberwell on May 5, 1978, following another stroke, full of years, covered with honour, and his passing was mourned by his family, his many friends, associates and professional colleagues.
Bull was fiercely proud and defensive of the veterinary profession. For most of his career the number of veterinarians practicing in Australia was very small. He clearly saw the need for the profession to be seen and heard in relation to the livestock industries. But he was also essentially a scientist with a keen critical faculty developed over some years of disciplined, personal training. As a young graduate he did not have the opportunity for post graduate training as we know it today, but never-the-less he quickly achieved international recognition as an experimental pathologist.
At an early stage in his career, Bull developed a confidence in his own ability to think scientifically and to plan investigations. He naturally assumed the role of leader when working with others, but was always ready to acknowledge the contributions of his colleagues and competitors. He worked hard, and expected his associates to do likewise. He would listen to the opinions of others and weigh these against his own, but in matters for which he believed he had responsibility, he made the final decision and was prepared to take full responsibility for it. Sometimes he could be just a little frightening for his juniors and some of his seniors too. One never took any liberties with him in conversation, very few people addressed him by his Christian name. For most of his career he addressed his colleagues and associates by their surnames. Bull was a good conversationalist in an era when this was considered to be a social requirement. He was a good lecturer and a ready contributor to discussion in scientific meetings. When he was relaxed he had a ready wit accompanied at times by an acid tongue, which, however, was never abrasive. He had a fine mind, an artist's perception of beauty in nature and a scant regard for cant or hypocrisy in any form. He has left a mark on many aspects of veterinary science and particularly on the health and production aspects of the animal industries of Australia.
His dedication to his profession and to science will remain an inspiration to many young people beginning their careers. With his passing Australia lost one of its finest citizens, the veterinary profession one of its 'Grand old Men', and the Australian Academy of Science an honoured Fellow.
This memoir was originally published in Historical Records of Australian Science, vol.5, no.4, 1983. It was written by:
The writers gratefully acknowledge the assistance of Colin Smith, CSIRO Archivist, and the staff of the CSIRO Animal Health Laboratory, who made available files and material relating to Dr Bull's period with CSIRO.
Emeritus Professor John Turner, FAA, Sir Macfarlane Burnet, OM, FRS, FAA and Dr Richard Garran supplied information about the Wallaby Club of Victoria; Dr R F. Seamark provided very accurate and full details of the origins of the Medical Sciences Club of South Australia, and Dr R.W. Newlands and Dr W. Stephen Smith supplied information about the establishment of the Australian Veterinary Association and the part played by the late Dr Bull in these organisations.
We are grateful to Dr Peter Bull for providing personal family details of his late father and mother.
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