William G. Atherstone was the eldest son of Dr John Atherstone* and came to the Cape with his parents in 1820 in a party of British Settlers. The family lived in Uitenhage for some time, then in Cape Town, and in 1828 settled in Grahamstown. The next year Atherstone was sent to the Uitenhage Academy to study under Dr James R. Innes*, where he developed an interest in both medicine and geology. Returning to Grahamstown in 1831 he was apprenticed to his father. At the outbreak of the Sixth Frontier War of 1834-1835, having completed his apprenticeship, he passed an examination by a medical board and was appointed assistannt staff surgeon to Colonel Harry Smith. After the war he went to Ireland to continue his medical studies at Trinity College, Dublin. He was admitted as a member of the Royal College of Surgeons, London, in 1838, and was elected a Fellow in 1863. He lived in London for some time, but, unable for technical reasons to obtain the degree Doctor of Medicine in England, he went to Heidelberg. Here, on the basis of a six day written examination and a three hour oral conducted in French, he graduated with distinction as Doctor of Medicine (MD) in 1839. He then travelled the continent and returned to England to mary his cousin, Catherine Atherstone, in September that year.
Returning to Grahamstown in December, and having already been licensed to practise the previous month, he became a partner in his father's practice. He succeeded his father as district surgeon of Albany in 1855 (retaining the post to 1878), and gradually also as the region's most eminent physician. Following the first use of ether as an anaesthetic in South Africa by Alfred Raymond*, H.A. Ebden* and J. Esterhuyse* in April and May 1847, Atherstone perfomed and fully described the first major surgical operation under ether in South Africa in June that year. After some experiments he settled on a simple apparatus, consisting of a large bottle which contained some ether, sealed by a cork through which two glass tubes passed. One of these admitted air to the bottle, while the other was fitted with a mouthpiece through which the patient inhaled the vapour. He used his apparatus to perform a painless and successful amputation above the knee on the Deputy Sherrif of Albany, Frederick Carlisle. The operation was fully described in the local newspapers, particularly the Grahamstown Journal of 19 June 1847, and the South African Commercial Advertiser of 30 June 1847. Two years later, in May 1849, he became the first person in South Africa to use chloroform as an anaesthetic during an operation. Again the event was reported in the local press.
Atherstone was a pioneer in the Cape Colony's public health services and institutions. In 1858 he became the first medical officer of the newly erected Albany Hospital. In 1875 he was sent to England by the Cape government to study mental hospitals and to select a medical superintendent for the Grahamstown Lunatic Asylum, which was established that same year and which he helped to plan. As the leading member of the medical profession in the Eastern Cape he was often consulted by the government, and in 1883 chaired the Select Committee on Medical Law Reform. Furthermore, he is thought to have written the draft of the Medical and Pharmacy Act, No. 4 of 1891, on behalf of the Eastern Medical Association. That same year it was at his instigation that the Colonial Bacteriological Institute was established in Grahamstown - the first public health laboratory in the Cape Colony. He wrote a contribution on "Cape health resorts: Grahamstown and the Eastern Districts" for the Official handbook of the Cape of Good Hope (pp. 159-162) in 1886. The next year he gave up his medical practice owing to failing eyesight, but retained an active interest in medical matters. In 1896, at the age of 82, he was elected honorary president of the fourth South African medical congress and delivered an address on his career and experiences.
Atherstone made significant contributions to geology and palaeontology and achieved wide renown in these fields, being elected a Fellow of the Geological Society of London in 1864. While searching for the source of water-worn pebbles in the Swartkops River near Uitenhage in his youth he discovered the Enon conglomerate, then unnamed. But his enthusiasm for geology was only fired when Andrew G. Bain* exhibited his collection of Karoo fossils in Grahamstown in 1844, before sending them off to London. He and Bain became friends and together did a six weeks geological survey of the valleys of the Bushmans, Swartkops and Sundays rivers, during which they found the first dinosaur fossil in South Africa. The fossils that they collected were described in the Transactions of the Geological Society of London (1845-1856) by D. Sharpe. While travelling widely in the Eastern Cape in the line of his medical work Atherstone observed geological features, described them in his diaries, and collected fossils and geological specimens. One of his companions on some of these trips was his colleague and friend, Dr Richard N. Rubidge*. From October 1854 to February 1855 he visited Namaqualand on behalf of the Grahamstown Prospecting Company to investigate the copper deposits there. His report on "Namaqualand and its mining prospects" was published in the Eastern Province Monthly Magazine (Vol. 1, pp. 642-651; Vol. 2, pp. 1-8) in 1857. In June 1856 he delivered an important lecture on the geology of Uitenhage before the Grahamstown General Institute - an association founded in 1855 for the advancement of literature, science and art. He described the succession of rocks now known as the Uitenhage Group, giving the name Wood Beds to clays, sandstones and small-pebble conglomerates that contain fossil wood. The immediately underlying sandstones he named the Zwartkops Sandstone, and the basal conglomerate the Enon Conglomerate. He described the distribution of the beds, including the nature of their (Lower Cretaceous) fossils, and illustrated their relation to older and younger deposits by means of sections. The paper was published as "Geology of Uitenhage" in the Eastern Province Monthly Magazine (Vol. 1, pp. 518-532, 581-595) in 1857 and represents his most important contribution to geology.
In 1871 he was commissioned by the Cape government to investigate the reported discovery of gold in the Koup region, between the Swartberg and Nieuweveld ranges, and was accompanied by Thomas C.J. Bain*. No gold was found, but while hunting for fossils in the vicinity of Prince Albert he made his most important palaeontological discovery, namely a giant dinocephalion which he donated to the British Museum (Natural History) and which was named Tapinocephalus atherstonii in his honour in 1876. It became the zone fossil of the basal beds of the Beaufort Group. His trip was described in two articles in the Cape Monthly Magazine in 1871 and 1873, "From Grahamstown to the Gouph", and "Nuggets of the Gouph". In the second of these, noting that the Karoo rocks and their animal and plant fossils resembled those of India, he speculated that, at the time the strata were laid down, India and Africa may have been a single continent. Thus he was probably the first South African to consider the idea of continental drift. Other geological and palaeontological publications by him dealt with fossils from the Bethelsdorp salt pan and from the Cedarberg (Cape Monthly Magazine, 1872); notes on the Stormberg coal (with C. Evans, Mining Journal, London, 1871); and a Parliamentary Report on the Milwood goldfields (1889).
The most dramatic event in Atherstone's geological career happened in March 1867 when he identified a shiny pebble that had been found near Hopetown as a diamond of 21 carats. He determined its specific gravity, hardness, and its behaviour in polarised light with the help of some friends. One of these, Dr Ricards, later the Roman Catholic bishop, used the stone to scratch his initials in a pane of glass. It was the first diamond to be found in South Africa. Atherstone described it in the Geological Magazine in 1869 and proposed a comprehensive geological survey of Griqualand West, based on his belief that more diamonds would be found there. Despite the scepticism of British commentators he was proved right. In 1871 he visited the diamond fields in response to repeated requests to give geological advice and described his trip in the Cape Monthly Magazine (1871). Three years later he also visited the alluvial goldfields at Lydenburg in the Eastern Transvaal and published an account of his trip in the same journal (1874). While in the Transvaal he visited Potchefstroom, including its newly established but rather primitive natural history museum, and soon thereafter sent it a collection of minerals. When the short-lived South African Geological Association was founded in Grahamstown in June 1888 he was elected as its first president. And in 1895, when the Geological Society of South Africa was formed in Johannesburg, he was honoured despite his advanced age and blindness by being elected an honorary vice-president. The genus Atherstonia, of fossil fishes from the Beaufort Group, was named in his honour.
Atherstone was a man of impressive intelect, a true polymath with indomitable energy, wide vision and great enthusiasm for scientific knowledge, and considerable ability as a lecturer and writer. No wonder therefore that he played a leading role in diverse scientific endeavours and societies in the Eastern Cape for several decades. Thus on 17 April 1850 he observed a lunar occultation of the star nu-Geminorum, from which Thomas Maclear* calculated an improved value for the longitude of Grahamstown. In July 1855 he was one of the foundation members of the Grahamstown Medico-Chirurgical Society, soon renamed the Literary, Scientific and Medical Society (1855-1872, 1892-1903), under the auspices of which he delivered various classes and lectures. Its museum, started in 1855, soon developed into the Albany Museum. Atherstone played a leading role in both the society, serving as president from 1871 to 1878, and its management committee for the Albany Museum, over which he presided for many years until his death. He furthermore donated numerous natural history specimens to the museum collections over the years (including mammals, birds, snakes, and non-marine molluscs; fossil reptiles, plants and molluscs; and stone artefacts) and was still mentioned as a major contributor as late as 1890 when he was deep in his seventies. The Albany Natural History Society, founded in Grahamstown in 1867, elected him as vice-president or president every year until the society faded in 1875; and when it was revived from 1890 to 1892 he became president again. In 1866 he assisted P. MacOwan* and H. Bolus* in setting up the South African Botanical Exchange Society by serving as acting treasurer. He built up his own herbarium collection, which was donated to the Albany Museum in 1889, and also sent plant specimens to the South African Museum and the herbarium at Kew Gardens, near London. The plant genus Atherstonea (later included in Strychnos) was named in his honour by C.W.L. Pappe*, while the marine mollusc Ostrea atherstonei still commemorates him. He collected stone artefacts, principally from the Eastern Cape (Bushman's River, East London, Keiskamma River) and donated them to the British Museum. In 1867 he contributed a number of items to the collection of South African products displayed at the Paris Exhibition, including photographs of scenery in the Eastern Cape, a bushman bow and arrows, and various vegetable products. He was a member of the Cape of Good Hope Meteorological Commission for many years from about 1875 to his death, while years earlier, in 1862, he had been an official meteorological observer (one of only ten in the colony) for the commission. In 1885 he participated in the foundation of an Eastern Province branch of the (first) South African Medical Association and was elected its president. And at an advanced age, having been president of the Eastern Province Branch of the British Medical Association for some time, he was made its honorary president in January 1896.
In addition to his contributions to science and medicine Atherstone played a role in several of Grahamstown's public institutions. In 1843 he was already a member of the committee of the Grahamstown Public Library, and he served on the committee of the Grahamstown Botanic Gardens for many years. He was a foundation member of the Grahamstown Philomatic society, formed in July 1848 for "the cultivation of rhetoric, literature, and general knowledge". In 1855 he became a member of the executive committee of the Eastern Province Agricultural Association. He served on the city council of Grahamstown during 1880-1882. In 1881 he was elected a member of the Cape Legislative Assembly for Grahamstown, and from 1884 to 1890 was a member of the Legislative Council for the South-Eastern Province.