[5] Fraser served as house surgeon, first in the Royal Infirmary of Edinburgh and then at the Royal Hospital for Sick Children under Sir Harold Stiles, who was to have a powerful influence on Fraser's approach to surgical problems and scientific enquiry.

[4] As Stiles had treated bone and joint TB in children by radical excision there was a large pathological collection available for study.

He set out to investigate the claim by Robert Koch that the risk of humans acquiring TB by drinking milk from tuberculous cows was negligible.

[9][10] Fraser disproved Koch's view[11] by demonstrating that 60% of the bones and joints he examined had the bovine form of the causative organism, Mycobacterium bovis.

[3] He served on the Western Front as Regimental Medical Officer in the First Cavalry Division and then, as surgeon to a casualty clearing station, he treated the wounded from the Battle of Loos.

His studies on blood pressure in shock resulted in his being invited to join the Medical Research Committee's small group on surgical shock whose other members included distinguished physiologists like E H Starling, W M Bayliss and the future Nobel laureates C S Sherrington and Henry Dale.

[19] Fraser's wartime observations were a major contribution to this committee who were to pioneer the scientific basis of fluid replacement in surgical shock.

[2] He produced a book with Cuthbert Wallace about his medical experiences during the war, Surgery at a Casualty Clearing Station, which was published by A & C Black in 1918.

He travelled overland to Los Angeles and crossed the Pacific to Honolulu, to Samoa, Fiji, New Zealand and Australia.

[5] Fraser's surgical career encompassed paediatric, abdominal, cardiothoracic and breast surgery and he wrote extensively on all of these.

[4] In the 1943 Birthday Honours he was made a Baronet with the creation of the Fraser Baronetcy, of Tain in the County of Ross.