James A. Ross studied at Queen's University, Dublin, Ireland, where he qualified as Doctor of Medicine (MD) and licentiate of the Royal College of Surgeons of Ireland (LRCSI) in 1868, and as Master of Surgery (MCh) the next year. During the next few years he worked as visiting surgeon at Birkenhead Hospital (England), resident physician at the North Staffordshire Infirmary, and physician at the Newry General Hospital and Fever Infirmary (Ireland), though not necessarily in that order. Among others he published a paper on "Conjoint scarlet fever and measles" (Medical Times and Gazette, 1869) and contributed to another on "Diseases of the lungs affecting those who work in dusty atmospheres" (Dublin Journal of Medical Science, 1871).
In April 1876 Ross was licensed to practice in the Cape Colony. That same year he published a booklet on Consumption: its treatment by climate, with reference especially to the health resorts of the South African colonies (London, 1876, 70p). It included descriptions of the places he had visited, mainly in the Cape Colony and Orange Free State. During the eighteen-nineties he was briefly a member of the South African Philosphical Society, serving on its council for 1895/6. At this time he was also a member of the Cape of Good Hope branch of the British Medical Association.
Dr James A. Ross should not be confused with Dr John Ross*, who practised in the Cape Colony until his death in 1891.