Australian Dictionary of Biography

Alan Walsh, 1977

National Archives of Australia, B941

Sir Alan Walsh (1916–1998), physicist and inventor of atomic absorption spectroscopy, was born on 19 December 1916 at Hoddlesden, Lancashire, England, second of four children of Thomas Haworth Walsh, cotton mill manager, and his wife Betsy Alice, née Robinson. Educated (1927–35) at Darwen Grammar School, he did well in all subjects and on the advice of his headmaster enrolled in the honours school of physics at the Victoria University of Manchester (BSc, 1938). He resided for two years at St Anselm Hall, the warden describing him as ‘a quiet, industrious student, with a sense of humour, and a sense of responsibility’ (Hannaford 2000, 181).  Upon graduating he was awarded a research scholarship at the Manchester Municipal College of Technology (MSc (Tech), 1944), where he worked for a year on the use of X-rays to determine the structure of β-carotene.

In the week that World War II began in September 1939, Walsh commenced work in London at the British Non-Ferrous Metals Research Association (BNF). His task was to work on ‘the development and application of spectroscopic methods of metallurgical analysis’ (Walsh 1988, 81). This was the start of his lifetime of use-inspired basic research. His immediate wartime activity was to determine from shot-down German bombers which metals had been used in their construction. He contributed to the development of atomic emission spectroscopy by devising methods to analyse aluminium, copper, and zinc alloys, and by the invention and commercialisation of the BNF Spectrographic Source Unit, which was manufactured by Hilger and Watts Ltd from 1950. In 1944 he was seconded to the Ministry of Aircraft Production’s Metal and Produce Recovery Depot at Durham, but he returned to the BNF in 1945 as chief spectroscopist. His work included developing a spectrographic technique for determining impurities in uranium metal as part of the British atomic bomb project.

In Melbourne in 1940 the Council for Scientific and Industrial Research (CSIR, later CSIRO) had established a division of industrial chemistry. Its chief, Ian Wark, was keen to apply modern techniques to solve problems facing the chemical industry and in 1944 established a chemical physics section led by Lloyd Rees. In 1946 Wark and Rees recruited Walsh to set up a laboratory for emission spectrographic analysis and to research infrared spectroscopy. Walsh commenced work in April 1947 at the Fishermans Bend laboratories where, he later noted, ‘individual freedom and initiative were not only permitted, they were actively encouraged’ (Wark 1979, 7). Soon after his arrival in Melbourne, he met Audrey Dale Hutchinson, an English-born nurse, whom he married on 25 June 1949 at St Peter’s Church of England, Eastern Hill.

Walsh’s first project at CSIR was to install the division’s new infrared spectrometer, which was manufactured by the American corporation Perkin-Elmer Inc. Observing that the resolution of the instrument was inadequate, he devised a modification that was patented by CSIR and licensed to Perkin-Elmer in 1953. He also initiated an atomic emission spectroscopy project, building on his work at the BNF, but the source unit built by the CSIR workshop to his BNF design proved insufficiently stable for the fundamental research he had planned. His colleague John Shelton later speculated that if Walsh’s emission project had been successful, he might not have invented atomic absorption spectroscopy.

In 1952, while reflecting upon his experiences of the spectrochemical analysis of metals (1939–46) and of molecular spectroscopy (1946–52), Walsh ‘began to wonder why, as in my experience, molecular spectra were usually obtained in absorption and atomic spectra in emission’ (Walsh 1974, 699A). He thought long about how to measure atomic absorption and the solution came to him while working in his vegetable garden one Sunday morning. The next day he set up a simple demonstration experiment and was able to report success by morning tea. He published his research in 1955.

Ignoring Wark’s advice to get back to research and leave the ‘hack’ work to others, Walsh played an active role in the development and commercialisation of his invention. He visited several laboratories and companies in 1953 and the next year Hilger and Watts signed an exclusive licence to manufacture his instrument, the atomic absorption spectrophotometer. Unhappy with the company’s progress, in 1958 Walsh decided to put together a do-it-yourself kit for laboratories to apply the atomic absorption method. It included some imported components and others manufactured in Australia by small companies that had been persuaded by Walsh to participate in his project. He travelled widely to promote his method and by 1962 more than thirty of the kits had been supplied to Australian laboratories and ten more overseas. That year both Techtron Appliances Pty Ltd in Melbourne and Perkin-Elmer took out licences to manufacture Walsh’s instrument. During the 1960s the use of atomic absorption spectroscopy to determinine the concentration of elements in solid or liquid samples became widespread.

Walsh is one of the few individuals to make an important contribution to basic science, to foresee and implement the application of his work, and to catalyse a new industry. His colleague Peter Hannaford observed that he possessed ‘a rare combination of vivid imagination and experimental practicality’ and that his work ‘was characterized by a remarkable simplicity and elegance, a hallmark of many great scientists’ (2000, 199–200). His invention of atomic absorption spectroscopy was one of the most significant advances in chemical analysis of the twentieth century. It resulted in royalties for CSIRO and a stimulus to Australian employment through local manufacturing, but its greatest economic benefit was the productivity improvements generated for industrial users. His colleague John Willis later observed that the atomic absorption method ‘had applications in fields as diverse as medicine, agricultural science, wine making, minerals exploration and metallurgical analysis’ (Willis 1998, 22).

A respected mentor and role model, with ‘a wonderful English North Country humour’ (Hannaford 2000, 200), Walsh was an avid follower of cricket, and enjoyed red wine, ocean swimming, and gardening. He was appointed assistant chief of the CSIRO division of chemical physics in 1962 and was knighted following his retirement in 1977. He then became a consultant (1978–82) to Perkin-Elmer and in 1982 was invited back to CSIRO as a senior research fellow. Among his many honours, he was elected a fellow of the Australian Academy of Science (1958), the Royal Society of London (1969), and the Australian Academy of Technological Sciences (1982). A recipient of the royal medal (1976) of the RSL and the Matthew Flinders medal (1980) of the AAS, he was also made an honorary doctor of science by both Monash (1970) and Manchester (1986) universities. Survived by his wife and their two sons, Sir Alan died on 3 August 1998 at Prahran, Melbourne, and was cremated. A spectroscopy laboratory (1994) at CSIRO and the Alan Walsh medal of the Australian Institute of Physics were named in his honour.