Thomas received his medical training at The London Hospital, entering in 1887, he qualified L.R.C.P., M.R.C.S. in 1894. In 1904 he went back to the hospital and held appointments of clinical assistant in both the Ophthalmic Department, then the Light Department. He then entered private practice at the Church End, Finchley, and was active in promoting the King Edward Hospital in Finchley, becoming its first medical officer. Thomas was also a Lecturer and Instructor to the V.A.D. In August 1916, he joined the R.A.M.C. He first served in Southsea, then went to Luton and Bedford. After that he was appointed to the hospital ship “Essequibo”, and sailed to and from America, and afterwards to and from France. When on one of these voyages, Thomas was found unconscious in his berth. He was sent to Netley, where he partially recovered and was sent to a nursing home in Hampstead. He died at the nursing home, after received a second seizure of cerebral haemorrhage. Thomas was the son of Adam and Elizabeth Smith; and the husband of Eliza Ruth Smith of 3 Redbourne Avenue, Church End, Finchley, Middx - they had 5 children.