G.W Bampfylde Daniell, medical practitioner and anaesthesiologist, was the son of Reverend G.W. Daniell. He received his medical training at St George's Hospital, London, qualifying as a Member of the Royal College of Surgeons (MRCS) of England and a Licentiate of the Royal College of Physicians (LRCP) of London in 1888. The next year he came to the Cape Colony, where he was licensed to practice on 8 June 1889, and settled as a general practitioner in Caledon. There he remained for most of the next eight years (though in 1893 he was listed as living in nearby Napier), taking a special interest in the local warm baths. He became medical superintendent of the Caledon Mineral Baths Sanatorium and medical officer of health to the Caledon Municipality. His first publication relating to the baths was a paper entitled "The mineral waters of Caledon", written for the 1893 medical congress and published in the South African Medical Journal (1895, Vol. 2, pp. 242-246 and 309-314). This was followed by two contributions under the same title, one in The South African climate (London, 1897) by W.C. Scholtz*, the other a lengthy paper written for the 1897 medical congress and published as a pamphlet (Cape Town, 1897, 64p). Later he expanded this work into an excellent history of the Caledon Baths Sanatorium and the work done there, The climate and mineral waters of Caledon, South Africa (London, 1902). He recommended both drinking and bathing in the hot mineral water, which he considered beneficial for aenemia, rheumatism, gout, neuralgia, chronic diarrhoea, skin diseases, and many other complaints.
Daniell became a member of the Cape of Good Hope branch of the British Medical Association in 1892 and by 1898 was a member of the (second) South African Medical Association. At some time he was elected a Fellow of the Royal Society of Medicine. After the Anglo-Boer War (1899-1902) he returned to England to specialise in anaesthetics, working as anaethetist in several London hospitals to the middle of 1903 and then practising as an anaethetist in Edinburgh, in partnership with Dr T.D. Luke, to the end of 1904. During these years he was also an instructor in anaesthetics in both London and Edinburgh. He used several agents in addition to ether and chloroform, such as ethyl chloride and a mixture of nitrous oxide and oxygen, and developed or modified equipment to make administration of the new agents safer and simpler. Some of his early modifications of apparatus and original designs were displayed in the anaesthetics Museum of the British Medical Association in 1910, and he has been described as "an insatiable gadgeteer" (Parbhoo, 1987, p. 714). His work was reported in the British Medical Journal in 1903 and 1904 and in various later papers in this and other British journals. In January 1906 he returned to South Africa and started to practise as an anaesthetist in Cape Town. The next year he became the first person to be appointed as a specialist anaesthetist to a South African hospital (Johannesburg General) and was licensed to practise in the Transvaal. However, in 1908 he returned to Cape Town as a general practitioner while continuing to work in anaesthetics.
Daniell advocated the use of ethyl chloride as a general anaesthetic for short operations in "Chloride of ethyl as a general anaesthetic" (South African Medical Record, 1904 and 1905; also Transvaal Medical Journal, 1906/7, Vol. 2). He made the same point in a paper read before the Dental Society of the Cape of Good Hope, "On chloride of ethyl as a general anaesthetic in dental surgery" (South African Medical Record, 1907, with a similar paper in the Transvaal Medical Journal, 1906/7, Vol. 2) and returned to the subject in later articles on general anaesthesia in dental surgery (South African Medical Record, 1913, 1919). In a paper presented to the Transvaal Medical Society, "Some observations in connection with general anaesthesia" (Transvaal Medical Journal, 1908/9, Vol. 4), he discussed the theories, chemistry and physiology of general anaesthesia in detail. He also stressed the importance of alleviating the anxiety of patients before operations. The Transvaal Medical Society elected him an honorary member in 1909. Later he described his "Improved apparatus for the administration of warmed ether vapour" (South African Medical Record, 1918). His last paper, "General anaesthesia in ear, nose and throat operations", appeared in the South African Medical Journal in 1932.
In 1919 Daniell was appointed as a specialist anaesthetist at New Somerset Hospital, Cape Town, and two years later also as lecturer in anaesthetics at the Medical School of the University of Cape Town. He retired from Somerset Hospital in 1923. That year, and again in 1932, he visited Britain to attend meetings of the British Medical Association. He retired from the university in 1927 and settled in Grahamstown in about 1935. In his time he was regarded as the highest South African authority in anaesthesia.