Educated at the General Hospital, Birmingham, and at University College, London. In 1872 he was House Surgeon at the Male Lock Hospital, and in 1873 was Resident Medical Officer of the Lock Wards at the Royal Portsmouth Hospital. He then entered the Bengal Army as Surgeon on September 30th, 1873, and was promoted to Surgeon Major on Sept 30th, 1885. He was for many years stationed at Allahabad, the seat of Government of the North-West Provinces, as Junior Civil Surgeon, and was well known as an ardent worker professionally and for the welfare of his station. He was among the founders of the North-West Provinces and Oudh Branch of the British Medical Association in 1882. Allahabad was the headquarters of this branch, which languished and disappeared when Deakin left the district. He was compelled twice to take sick leave, in 1876 and 1885. Early in 1886 he was posted as Civil Surgeon to Mirzapur, but returned subsequently to military duty, and was posted to the medical charge of the 34th Pioneers when that regiment was raised in 1887. He served with it in the Hazara or Black Mountain campaign of December, 1888, and was mentioned in despatches on account of gallantry at the action of Kotkai. The *Pioneer*, the principal Indian newspaper, referred to him, at the time of his early death, as "well known a few years ago as one of the most skilful surgeons in these Provinces". He died of enteric fever at Jhelum in the Punjab on November 17th, 1889. Publications: Deakin contributed papers to the *Lancet*, the *Brit Med Jour*, *Indian Med. Gaz*, and other journals, and owned, published, and edited from 1882-1889 the *Indian Med Jour*, which ended with his death. The title from 1882-1884 was *Transactions of the NWP and Oudh Branch of the British Medical Association*. *The Contagious Diseases Acts*, 1864, 1866, 1868 (Ireland), 1869, *from a Sanitary and Economic Point of View*, 8vo, London, 1872.