Captain Robert Mitchell studied engineering, became a local councillor and borough treasurer, and declined an invitation to stand for parliament before going to Edinburgh University to study for a BSc in Chemistry in 1928. In 1933, he graduated in medicine and obtained his MB ChB.
During the Second World War, Robert Mitchell served in Royal Army Medical Corps, where he was responsible for public health in Malta and later served in Sicily where he was mentioned in despatches.
In 1953, Robert Mitchell became a Medical Officer of Health for Burton on Trent. He was previously an Assistant Medical Officer of Health for Oldham at a time of serious staff shortages. During the next twenty years he developed staff and services considerably. Having himself had poliomyelitis, he was especially concerned with preventing this disease and was responsible for an unpopular closure of all leisure activities in and on the Trent after securing the ministry's help over inadequate cooperation from the local council. The immunisation figures rose, and he was singular in resisting strong pressure for too early use of the Salk vaccine until adequate safety standards had been established. He succeeded in persuading the local authority to build and develop excellent adult training and mental welfare centres.
Dr Mitchell was rarely met outside his work and never went away on holiday. His hobbies included horology and all do it yourself activities at his home: any local plumber, electrician, or builder called in always learnt far more than he expected. He had an encyclopaedic knowledge. After 40 years with Dorothea, his younger sister and only relative, he was desolated by her death. Afterwards he pacified his active mind by regular visits to the library at Burton Graduate Medical Centre.