William Sage Rapson (14 August 1912 – 25 June 1999) was a New Zealand and South African chemist. His initial career was inorganic chemistry but he moved intoinorganic chemistry with particular emphasis on gold. His research interests ranged from fish oil throughcoal liquefaction toX-ray diffraction.

Rapson was one of seven children raised on a small farm inKaihu, New Zealand. He attendedMount Albert Grammar School where he was a Rawlings Scholar and later Senior National Scholar. He then went on toAuckland University College as a Junior University Scholar, Senior University Scholar, Duffus Lubecki Scholar and lastly Sir George Grey Scholar. He attained his master's degree at the age of 20 and in 1933 he became lecturer in chemistry at the University College.^[1]

In 1934 he went to Oxford to study organic chemistry withRobert Robinson. He developed theRapson-Robinson synthesis, while completing his thesis in 1935 at the age of 23. He was then appointed lecturer in organic chemistry at theUniversity of Cape Town (1935–41).^[1]

In 1946 he became professor designate of Chemistry after having been a Senior Lecturer. He did pioneering work on fruit and fish resource of theWestern Cape region which became the foundation for South Africa's fish oil industry. He also researchedcoal liquefaction and collaborated with physicists at the University of Cape Town on the development ofX-ray diffraction.^[1]

He was the first director of the National Chemical Research Laboratory of theCouncil for Scientific and Industrial Research (CSIR) inPretoria. His research areas included South African water and mineral resources. In particular, deacidification anddesalination methodsfor waste dumps and rivers. He identified a type of grass that would grow in theacidic sand of gold minetailings dumps aroundJohannesburg to assist with preventing the sand from polluting the nearby rivers.^[1]

In 1958 he was promoted to vice-president of CSIR. He was then appointed Research Advisor to theTransvaal and Orange Free State Chamber of Mines, with the aim of improving production and reducing waste. His research, in collaboration with T. Groenewald was published in the journalsGold Bulletin andGold Technology. In 1978 Rapson and Groenewald co-authored the bookGold Usage, the first textbook on gold to be published sinceDie Edelmetalle und Ihre Legierungen^[2] by E. Raub (1940). Rapson later went on to translateDie Edelmetalle und Ihre Legierungen into English but that version was only published after his death.^[1]

In 1937 Rapson married Joyce Rachel Abey, who had been permanently disabled in a motorcycle accident prior to them meeting. They had two daughters. She died in 1996. Rapson died in 1999.^[1]

• Rapson, William Sage; Robinson, Robert (1935). "307. Experiments on the synthesis of substances related to the sterols. Part II. A new general method for the synthesis of substituted cyclohexenones".Journal of the Chemical Society (Resumed): 1285.doi:10.1039/JR9350001285.
• Rapson, W. S. and Groenewald, T. (1978)Gold Usage. Academic Press.ISBN 0-12-581250-7.

• Austin, Brian (2001)Schonland – Scientist and Soldier, IOPP, Bristol,ISBN 0-7503-0501-0

• 1912 births
• 1999 deaths
• New Zealand chemists
• 20th-century South African scientists
• University of Auckland alumni
• People from the Northland Region
• New Zealand emigrants to South Africa
• People educated at Mount Albert Grammar School

• CS1 German-language sources (de)
• Articles with short description
• Short description is different from Wikidata
• Use dmy dates from March 2015
• Articles with hCards