Born at Islington on July 21st, 1837, the youngest son of Nicholas Mason, a lace merchant of Wood Street, Cheapside, London. He was educated at the Islington Proprietary School, where the Rev John Jackson, afterwards Bishop of London, was the head master. He next went to King's School, Canterbury, and then pursued his medical studies at King's College, London, where in later years he was made an honorary Fellow. At King's College Hospital he was House Surgeon in 1859-1860 and came under Sir William Fergusson, who thought so highly of his surgical ability as to engage him as private assistant. He was appointed Assistant Surgeon at King's College Hospital in 1863 and Surgeon to the St Pancras and Northern Dispensary. In 1867 he was elected Assistant Surgeon to and Lecturer on Anatomy at Westminster Hospital, becoming full Surgeon in 1871. Mason was then invited to join the medical staff of St Thomas's Hospital as Assistant Surgeon and Lecturer on Anatomy on the opening of the new buildings in 1871. He accepted the invitation and became full Surgeon in 1876, when he exchanged the lectureship on anatomy for that on practical surgery. He filled many important offices in the Medical Society of London, being Orator in 1870, Lettsomian Lecturer in 1878, President in 1882, and subsequently Treasurer. He contributed much to the surgery of cleft palate. He died of acute erysipelatous inflammation of the throat on June 5th, 1886, leaving a widow without children, and was buried at Highgate Cemetery. Mason was a man of genial character, generous, hospitable, and possessed of considerable musical talents. There is a portrait in the Medical Committee Room at St Thomas's Hospital, a lithograph portrait in the College Collection, and a photograph in the Fellows' Album. Publications:- *On Hare-lip and Cleft Palate*, 8vo, London, 1877. *On the Surgery of the Pace*, 8vo, London, 1878. Editor of the *St Thomas's Hosp Rep*, 1879-86, ix-xiv.