Australian Dictionary of Biography

David Arthur Welsh (1865-1948), pathologist, was born on 19 November 1865 at Montrose, Forfarshire, Scotland, son of David Welsh, sheep-farmer, and his wife Emma, née Hall. Receiving his early education at Arbroath, in 1883 he entered the University of Edinburgh (B.A., 1887; M.B., Ch.M., 1893; M.D., 1897). He took first-class honours three times — in mathematics with the Drummond scholarship (1887), in clinical medicine and pathology with the Murchison scholarship (1893), and, with a gold medal, for his doctoral thesis on the structure and function of a parathyroid (1897).

Moved by what he had seen of patients' physical suffering and social problems, on first graduating Welsh had become a resident physician to Sir Thomas Fraser at the Royal Infirmary which he found the 'most interesting time in my life and the most precious part of my training'. He then spent about a year at the Morningside Asylum where he came into contact with Ford Robertson. As junior assistant in pathology at the university, Welsh worked directly under Robert Muir, a lifelong colleague and friend, whose sister Elizabeth he married in Edinburgh on 11 April 1899 with United Presbyterian forms. He also tutored in medicine. The importance of pathology to the practising clinician was to remain one of his obsessions.

Appointed foundation professor of pathology in 1901 at the University of Sydney, in March 1902 Welsh joined (Sir) Thomas Anderson Stuart and J. T. Wilson in a triumvirate ('Taffy', 'Andy' and 'Jummy' to their students) who transplanted the traditions of the Edinburgh school to a new environment.

His department consisted of three rooms: the professor's 'retiring room', a single laboratory and a practical classroom; the lecture theatre and museum were shared. Welsh's responsibility was to teach pathology (all branches of laboratory medicine) to veterinary and dental as well as medical students, and also to provide (unaided) the pathology services to Royal Prince Alfred Hospital. At first, his enthusiasm and experience compensated for the lack of facilities and inadequate support staff. He established an innovative teaching programme with excellent practical classes, particularly in haematology, and continued to emphasize the contribution of pathology to day-to-day clinical problems. Welsh maintained his own clinical expertise and was elected a fellow of the Royal College of Physicians, Edinburgh, in 1911.

In collaboration with several colleagues in Sydney, Welsh published clinical descriptive papers, and a number of reports on Australian marsupial species. His most important scientific work concerned immunological reactions. In a long series of papers with Henry Chapman he described the quantitative aspects of immune precipitation. Their most significant finding was that antibody (not antigen as previously believed) contributes the bulk of the mass of immune precipitates. Welsh's family and academic ties with Edinburgh remained strong and most of this work was published both in Australian and Scottish journals.

The rapid development of laboratory medicine in the early twentieth century entailed a heavier work-load for Welsh. By 1925 it was clear that a single pathologist could not hope to provide diagnostic services for a large modern hospital while maintaining the research and teaching obligations of a university department. Dean of the faculty of medicine in 1927-29, Welsh wrote little over the next decade. He increasingly relied on didactic lecturing and depended on Muir's famous textbook for teaching. The separation of the hospital and the university department of pathology in 1925 brought some relief, but necessitated the abandonment of Welsh's plan to integrate laboratory and clinical training in the advanced years of the medical course. He retired in 1935.

Welsh next turned his interest to the problems of malignant disease and to the effects of ionizing radiation on cell biology. He collaborated with his son Arthur and Drs Amphlett and Kenny at the new radium institute at R.P.A.H. in studies of squamous cancer and radiation. Treatment of his own skin condition led to the formation of epithelioma and to the amputation of his foot. The consequent pain and disability clouded his final years and diminished the pleasure he took in his beloved golf. Survived by his wife and son, he died at his Wahroonga home on 13 May 1948 and was cremated. His estate was sworn for probate at £2292.