Arthur was educated at Edinburgh University, where he graduated M.B., C.M. in 1888. After qualifying he spent a year as resident medical officer to the Chalmers Hospital, Edinburgh, and was also house surgeon at the Royal Maternity and Simpson Memorial Hospital , Edinburgh. In 1891 he took the degree of M.D. with honours at Edinburgh University, and in 1893 he became a Fellow of the College of Surgeons, Edinburgh.
He began his practice in Bedford in 1892, whilst also becoming a medical examiner and referee for a large number of life insurance companies, and held the post of Admiralty surgeon to Bedford and district. In 1896 the mayor of Bedford present him with the testimonial of the Royal Humane Society for rescuing a girl from the flooded Ouse. He was later elected president of the Bedford Medical Society, and in 1913 he presided over the South Midland Branch of the British Medical Association. He also took an active part in the Bedford District Nursing Association and the Bedfordshire Rural Nursing Association, and acted for a number of years on the executive committee of the local branch of the Society for the Prevention of Cruelty to Children. When relaxing, he enjoyed playing golf, tennis, shooting, skating or curling. Arthur had served for twenty eight years in many different capacities in the Volunteer and Territorial Corps, including No 4 (University) Coy, and the Royal Scots for eleven years. He served under three sovereigns, having taken part at Queen Victoria’s funeral; and at the Coronations of both King Edward VII and King George V. When war broke out he joined the R.A.M.C. (T.F.) and was on service as Major, becoming attached to the Headquarters Staff of the East Anglian Royal Engineers. In 1917 he received the Territorial Decoration, but in the November had to relinquished his commission on account of ill health. He received the King Edward’s Silver Medal for long service in 1919. Arthur died at Bedford. He was the second son of William Hartley of Comlongon, Dumfriesshire; and the husband of Margaret (daughter of James Stewart), married in 1908. They had three daughters and one son.