Arthur was educated at Aberdeen Grammer School and Aberdeen University, where he graduated M.B. Ch.B. in 1906 and D.P.H. 1907. In 1914 he obtained the new diploma of psychiatry at the University of Edinburgh. For a short time he was Resident Physician and Surgeon in the Sick Children’s Hospital, and subsequently held the appointment of Senior Medical Assistant at the Royal Asylum, Aberdeen. He joined the Royal Army Medical Corps, Territorial Force in 1902, and later the University Corps of the Scottish Horse. On 2nd February 1909, he received a commission as Lieutenant in the R.A.M.C. [T.F.] and was promoted to Captain on 2nd August 1912. When war was declared he volunteered for Imperial service and left for the Dardanelles with the 1st Highland Field Ambulance on 18th March 1915. He was killed in Gallipoli, whilst making a final inspection before an impending battle of Cape Helles, which was to cover the opening moves of the Sulva Bay Landing. He was described by the medical profession as a man of great reserve, and only his intimates could appreciate his high ideals, his keen sense of humour and his full enjoyment of life. He was a delightful companion, a keen observer with a great gift for detail and for logical analysis, which was no doubt developed in the thorough training he went through for his professional work in Mental Science. His death was recorded in “Nature” (28th Aug 1915), whereby the writer observed: “His tenure of office at the Royal Asylum was a strikingly successful one; on both the therapeutic and the administrative sides he evinced gifts of no ordinary type.” Lt/Col Thomas Fraser, commanding 1st Highland Field Ambulance wrote: “To everyone in the Ambulance, Arthur had endeared himself by his excellent qualities of head and heart, by his devotion to duty and by his keen interest in everything that pertained to the good of the Ambulance as a whole. The men of his own section adored him, and there was no better trained or harder working unit in the Peninsula. To myself personally his loss is irreparable. Amongst a group of excellent officers, I regarded him as outstanding. He had been the greatest possible help to me, first as Transport Officer and then as Commander of C Section. We had been working together for just a year, and our most intimate association had been absolutely without friction. He had a great capacity for work, was an excellent organizer with a firm grasp of detail, of cool and sane judgement and a high sense of discipline, which was an outstanding example to all. Of his personal qualities and his unswerving loyalty I shall say nothing, save that they leave with me a lasting and unclouded memory which is full of pleasantness and cannot be effaced. We are all shocked by the suddenness of his end, though glad it was a painless one. He was hit in the head by a sniper while making final arrangements before an action, during which it was his turn to take charge of our Advanced Dressing Station. This was over 4 miles from our camp, but I decided that his body should be brought back to the Military Cemetery at Lancashire Landing, near which we have been stationed so long. There we buried him, wrapped in the colours for which he had given his life, yesterday afternoon at 2.14. A Church of England clergyman officiated. It was a most impressive service, to an accompaniment of shells from Achi Baba, which had been our daily and nightly portion for so long. There he sleeps in the company of many heroes who have laid down their lives for their country on his inhospitable and deadly shores, none of whom did his duty more earnestly or gallantly than he. I have received the enclosed letter from Col. Yarr, who at the landing was A.D.M.S. of the 29th Division. It speaks for itself, and shows how your son was regarded and appreciated at Headquarters.” The letter from Col Yarr was as follows: “I hope you will express not only the regret of his unit but the grief of the whole 29th Division at the loss of a gallant comrade. Both in the 29th Division and in the 8th Army Corps, of which it forms part, I have known Capt Kellas well; his watchword was Duty, and he died as he lived, a fearless, gallant officer and gentleman.” Arthur was the youngest son of the late James Fowler Kellas, Superintendent of the Mercantile Marine for the Port of Aberdeen and of Mary Boyd Kellas, his wife of 48 Carden Place, Aberdeen.