William was educated at Kimberley High School, and Edinburgh University. From 1902 - 1903 he was a member of the Cadet Corps, attaining the rank of Cadet Serjeant-Major, then he joined the Officer Training Corps, Medical, from 1910 to 1912. During this time, in 1911, he qualified M.B., Ch.B. He then qualified F.R.C.S. in 1914. On 12th August 1914 he took up a commission at the rank of Lieutenant in the R.A.M.C., Special Reserve. He gained promotion to the rank of Captain on 1st April 1915. On 4th May 1915 he arrived in Aldershot, reporting himself for duty with No 17 Casualty Clearing Station. He then sailed with the unit to Havre on S.S. St Petersburg, entering the war in France on 21st May 1915. On 27th July 1915 he acted as surgical specialist with a sub-section of the unit sent to Remy Siding, where he operated on two cases of acute appendicitis. He himself became sick on 20th September 1916, being transferred to No 15 Casualty Clearing Station. He rejoined his unit the following 4th October. On 5th April 1917 he was posted to No 30 Casualty Clearing Station for temporary duty, returning on 24th May. He also served temporarily with Nos 11, 53 and 62 Casualty Clearing Stations. On 4th January 1918, he was appointed acting Major, and on a couple of occasions took over command of No 17 Casualty Clearing Station when the commanding officer went on leave. He left the unit to report for duty in England on 11th December 1918, relinquishing the rank of acting major from 12 December 1918.