In 1904 Granville Hey became a member of the British Homoeopathic Society. He practiced at Crofts House, Altofts, Yorkshire, and later in London at 4 Fopstone Road, Earls Court, at 8 Bentinck Street, at 104 Cromwell Road, South Kensington, and 84 Harley St. He served in the Edinburgh and East of Scotland Hospital during the 1900 South African War, and participated in the homeopathic Neully sur Seine Hôpital militaire auxiliaire in World War I.
Clarence Granville Hey was a colleague of William Bayes, Charles Harrison Blackley, John Galley Blackley, David Dyce Brown, George Henry Burford, James Compton Burnett, John Moorhead Byres Moir, John Henry Clarke, Henry Arthur Clifton Harris, Paul Francois Curie, Robert Ellis Dudgeon, John Epps, Washington Epps, Giles Forward Goldsborough, James Johnstone, Richard Hughes, Thomas Robinson Leadam, Edwin Awdas Neatby, Alfred Crosby Pope, Mathias Roth, Charles Thomas Knox Shaw, Harold Wynne Thomas, Margaret Lucy Tyler, Charles Edwin Wheeler, David Wilson, James Craven Wood Stephen Yeldham and many others.
Granville Hey was born in Whitwood Mere, Yorkshire, one of six sons of grocer William Hey (1833 – 1908) and Sarah Jane Brook (1839 – 1915).
In May, 1905 Hey, then Resident Medical Officer at the London Homeopathic Hospital was elected by the hospital Ladies’ Committee as their first Traveling Scholar in Gynaecology and the Diseases of Children. He subsequently spent three months in Vienna studying homeopathy at the clinics and taking classes at the Universities there.
On his return to Britain, in August, 1905, Hey married Edinburgh-born Christina Weir Orr (1867 – 1941). They had a daughter, Constance Rona Granville Hey (born 1907).
The International Homeopathic League was founded in Rotterdam (Holland), on the 10th September, 1925 by Roy Upham, the first President, George Burford, the first Vice President, and Harold Fergie Woods, Clarence Granville Hey, Edwin Awdas Neatby, Victor Ellwood, M. Fremont Kranz Busch, Jean Paul Tessier Junior, E. C. Tuinzing, Augusto Vinyals, Juan Bertran, Petrie Nicholas Grouleff, A. Moeira Piedras and Pierre Schmidt.
Granville Hey contributed cases to Therapeutics of Cancer by John Henry Clarke, and to The Journal of the British Homeopathic Society, The Journal of Surgery, Gynecology and Obstetrics, The British Homeopathic Review.
Clarence Granville Hey died 11 August, 1941. His wife Christina died on 2 September 1941 in Llandudno, just three weeks later.