Leonard was educated at Marlborough College, and at St Bartholomew’s Hospital, qualifying M.R.C.S., L.R.C.P. in 1903. In 1909. after a period of post-graduate study in Berlin and Vienna, he obtained the diploma of public heath [D.P.H.]. For many years he was an assistant medical officer in the Public Health Department of the London County Council. He also became senior assistant Ministry of Health, and school medical officer under the Devon County Council, as well as assistant-surgeon to the West of England Eye Infirmary in Exeter. He had also become a well known Rugby player. When war broke out, Leonard was serving, at the rank of captain, in the 1st Wessex Field Ambulance, Territorial Force. On the 24th October 1914 he transferred, at the lower rank of lieutenant, to the 3rd East Anglian Field Ambulance. His service, throughout the war, included serving as D.A.D.M.S. (Sanitary), for two and a half years, at the Headquarters of the 4th and 5th Armies, and later as a specialist sanitary officer at H.Q. Eastern Command. He entered the war in France on 3rd January 1917, joining the 1st Division the following day, where he assumed command of No 13 Sanitary Section. He ceased to be employed as the Sanitary Officer, 1st Division on 25th April 1917. He served with the R.A.M.C. Territorial Force, all in all, for over 12 years. On 16th January 1920 he received the O.B.E. (military) and was granted the rank of Major. He retired from the Army at the rank of Major and was appointed Deputy Commissioner of Medical Services at the Ministry of Pensions. He died in Roehampton, Surrey after an operation. He was the son of Dr L H Tosswill of Exeter.