John was serving with the 141st Field Ambulance on 25th June 1918 when he was admitted to the hospital of the unit 'sick'. He was discharged back to duty on the 28th June. On 26th January 1917 he was again admitted to hospital and transferred to III Corps Rest Station. On 13th March 1919 he was demobilized whilst on leave to the UK, and was struck off the strength of the unit.