John Murray Alexander was born in Sydney in 1913 and graduated in medicine from the University of Sydney in 1937.
He spent several years in residency at Sydney Hospital. He moved to Crown Street Obstetric Hospital then to the Royal Alexandra Hospital for Children (RAHC) at Camperdown where his lifelong interest in pediatrics began.
During World War II, John Alexander served in the Air Force and studied for Membership of the Royal Australasian College of Physicians which he obtained in 1942. In the same year he married Victoria Jean Harvey in the state of Victoria. He obtained Fellowship of the College in 1954 after recommendations from senior Fellows of the College as was the custom at that time.
After the war, he worked in general practice while obtaining honorary hospital appointments at Canterbury Hospital, the Tresillian Mothercraft Homes, and the Royal Alexandra Hospital for Children where he carried out outpatient duties from 1948 until his appointment as honorary physician in 1964. He retired in 1978.
John Alexander became an expert in childhood thoracic disease. He was a long-serving member of the Bronchiectasis Clinic. Bronchiectasis was common at the time, complicating measles, whooping cough, and the little understood Pink Disease. Pink Disease later became identified with chronic mercury poisoning, frequently iatrogenic in origin from the use of teething powders in small children. Chest physiotherapy and a limited list of antibiotics were the main treatments for bronchiectasis but thoracic surgery, mainly in the form of lobectomy, was beginning to be practiced in the hospital by Dr Tom Nelson. The knowledge and experience of John Alexander became extremely important in the choosing of appropriate patients for thoracic surgery. He also worked as a general physician in the Hospital.
John became a specialist pediatric physician at a time when modern pediatric practice was in its infancy and when private practice could not easily be sustained without the help of general practice. He took up successful private paediatric practice in Macquarie Street and in Campsie while working as an honorary pediatric physician at Canterbury Hospital. It was however at the RAHC where he had his greatest influence. There he was at various times chairman, secretary and treasurer of the Medical Board. For many years he was convenor of the Hospital Post-Graduate Education Sub-Committee and convenor of the regular Hospital Physicians' Meetings.
The Australian Pediatric Association, which held its first meeting in 1950, was an important organization for Australian paediatricians. John Alexander served as its honorary secretary from 1961 to 1967 and as vice-president from 1976 to 1977. In 1977 the Association was transformed into the Australian College of Paediatrics. John Alexander became its first president from 1977 to 1978.
In 1975 he was invited by the Australian Development Assistance Agency to lecture on paediatrics in Malaysia.
In 1978 at the age of 65 years he retired from medical practice. The Children's Hospital Bulletin at that time commented:
'The Alexander term has always been popular with residents and registrars, not only because of the variety of clinical problems that Dr Alexander attracts but also because of the sound practical teaching that they have gained from him.... Dr Alexander is widely known in this hospital as a fine clinician, a sound teacher and a good friend.'
John Alexander attended Sydney Church of England Grammar School (Shore) where he gained a good school record and a public exhibition to Sydney University. He was a keen cricketer both at school and at university. He played in second grade for North Sydney Cricket Club and used his skill often to save the honour of the Children's Hospital honorary medical staff in their cricket matches against the residents. Of his two sons, the younger was a grade cricketer. Harvey became a urological surgeon and Ron a civil engineer.
On retirement he studied German and attended the St Ives Probus Club. He was also a regular attendant with his wife, Jean, at the Australian Ballet performances at the Sydney Opera House. As time went on John Alexander moved to a retirement village in Gordon. On 7 November 2002, at the age of 89 years, he died in Royal North Shore Hospital of metastatic renal carcinoma.