David Leonard Chapman FRS (6 December 1869 – 17 January 1958) was an

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

physical chemist Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mech ...

, whose name is associated with the Chapman-Jouguet treatment (on the theory of detonation in gases) and the Gouy-Chapman layer (the surface layer of ions distributed on a charged surface). He was a

fellow A fellow is a concept whose exact meaning depends on context. In learned or professional societies, it refers to a privileged member who is specially elected in recognition of their work and achievements. Within the context of higher education ...

Jesus College, Oxford Jesus College (in full: Jesus College in the University of Oxford of Queen Elizabeth's Foundation) is one of the constituent colleges of the University of Oxford in England. It is in the centre of the city, on a site between Turl Street, Ship S ...

for 37 years, and was in charge there of the last college laboratory at the

University of Oxford , mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor ...

Education and early life

Chapman was born in

Wells, Norfolk Wells-next-the-Sea is a port town on the north coast of Norfolk, England. The civil parish has an area of and in 2001 had a population of 2,451,Office for National Statistics & Norfolk County Council (2001). Census population and household ...

but moved with his family to

Manchester Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The t ...

and attended

Manchester Grammar School The Manchester Grammar School (MGS) in Manchester, England, is the largest independent school (UK), independent day school for boys in the United Kingdom. Founded in 1515 as a Grammar school#free tuition, free grammar school next to Manchester C ...

. He then went to Christ Church, Oxford, obtaining degrees in chemistry (1893, 1st class) and

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

(1894, 2nd class).

Personal life

Campman was by reputation something of a scientific recluse, difficult to dislodge from his laboratory, although he did play a full part in University and College affairs. Away from his teaching and research, he was reserved and somewhat eccentric, but enjoyed golf, cycling and walking. He married one of his research students, Muriel Holmes (a member of the university's Society of Oxford Home-Students) in 1918 and together they had a daughter, Ruth. He died from cancer at his home in Oxford in 1958.

Career

Chapman was a science master at

Giggleswick School Giggleswick School is a public school (English independent day and boarding school) in Giggleswick, near Settle, North Yorkshire, England. Early school In 1499, Giggleswick School was founded on half an acre of land leased by the Prior an ...

for a time before becoming a member of staff at the

University of Manchester , mottoeng = Knowledge, Wisdom, Humanity , established = 2004 – University of Manchester Predecessor institutions: 1956 – UMIST (as university college; university 1994) 1904 – Victoria University of Manchester 1880 – Victoria Univ ...

. In 1907,

appointed him as fellow and tutor in charge of its new teaching and research laboratory. Chapman ran this until his retirement in 1944; the laboratory, the last college-run laboratory in the university, closed in 1947. Chapman was also vice-principal of the college (1926–44).

Research

Although Chapman took a keen interest in his students, research was his main priority. Chapman had a particular interest in the

photochemical Photochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 nm), visible light (400–7 ...

reaction of

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

and

chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine i ...

, establishing that minute traces of impurities caused unexpected consequences. He suggested the

steady state In systems theory, a system or a process is in a steady state if the variables (called state variables) which define the behavior of the system or the process are unchanging in time. In continuous time, this means that for those properties ''p' ...

hypothesis in 1913. He discovered that the interruption of light by a rotating sector caused the rate of the reaction to vary with the frequency of the sector and, in 1926, he was the first to apply this theory to measure the 'mean life' of a reaction intermediate. Other areas of interest were the theory of detonation in gases (the subject of an important paper that Chapman published in 1899, with reliable calculations of detonation speeds; the theory is still known as the Chapman-Jouget treatment) and the distribution of ions at a charged surface (with the name of the Gouy-Chapman layer being given to the surface layer that he envisaged).

References

{{DEFAULTSORT:Chapman, David Leonard 1869 births 1958 deaths People from Wells-next-the-Sea People educated at Manchester Grammar School Alumni of Christ Church, Oxford English physical chemists Academics of the Victoria University of Manchester Fellows of Jesus College, Oxford Fellows of the Royal Society

Education and early life

Personal life

Career

Research

See also

References