Thomas Graham (21 December 1805 – 16 September 1869) was a British

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe th ...

known for his pioneering work in dialysis and the

diffusion Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...

of gases. He is regarded as one of the founders of

colloid A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others extend ...

chemistry.

Life

Graham was born in

Glasgow Glasgow ( ; sco, Glesca or ; gd, Glaschu ) is the most populous city in Scotland and the fourth-most populous city in the United Kingdom, as well as being the 27th largest city by population in Europe. In 2020, it had an estimated popul ...

, and educated at the

High School of Glasgow The High School of Glasgow is an independent, co-educational day school in Glasgow, Scotland. The original High School of Glasgow was founded as the choir school of Glasgow Cathedral in around 1124, and is the oldest school in Scotland, and the ...

. Graham's father was a successful textile manufacturer, and wanted his son to enter into the

Church of Scotland The Church of Scotland ( sco, The Kirk o Scotland; gd, Eaglais na h-Alba) is the national church in Scotland. The Church of Scotland was principally shaped by John Knox, in the Scottish Reformation, Reformation of 1560, when it split from t ...

. Instead, defying his father's wishes, Graham became a student at the

University of Glasgow , image = UofG Coat of Arms.png , image_size = 150px , caption = Coat of arms Flag , latin_name = Universitas Glasguensis , motto = la, Via, Veritas, Vita , ...

in 1819. There he developed a strong interest in

chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...

, studying under Professor Thomas Thomson, who was impressed and influenced by the young man. He left the University after receiving his MA in 1824. He later studied medicine at the

University of Edinburgh The University of Edinburgh ( sco, University o Edinburgh, gd, Oilthigh Dhùn Èideann; abbreviated as ''Edin.'' in post-nominals) is a public research university based in Edinburgh, Scotland. Granted a royal charter by King James VI in 15 ...

and then briefly taught chemistry at the

Glasgow University , image = UofG Coat of Arms.png , image_size = 150px , caption = Coat of arms Flag , latin_name = Universitas Glasguensis , motto = la, Via, Veritas, Vita , ...

Portland Street Medical School. In 1828 he was elected an Honorary Fellow of the

Royal Society of Edinburgh The Royal Society of Edinburgh is Scotland's national academy of science and letters. It is a registered charity that operates on a wholly independent and non-partisan basis and provides public benefit throughout Scotland. It was established i ...

, his proposer was Edward Turner. He won the Society's

Keith Medal The Keith Medal was a prize awarded by the Royal Society of Edinburgh, Scotland's national academy, for a scientific paper published in the society's scientific journals, preference being given to a paper containing a discovery, either in mathe ...

for the period 1831–33. in 1830 he was appointed to be the first professor of chemistry at the Anderson's Medical School, a post later named the Freeland Chair of Chemistry. He also delivered lectures to the Glasgow Mechanics' Institution before moving to take up a professorship at the

University of London The University of London (UoL; abbreviated as Lond or more rarely Londin in post-nominals) is a federal public research university located in London, England, United Kingdom. The university was established by royal charter in 1836 as a degree ...

, where Graham founded the

Chemical Society of London The Chemical Society was a scientific society formed in 1841 (then named the Chemical Society of London) by 77 scientists as a result of increased interest in scientific matters. Chemist Robert Warington was the driving force behind its creation. ...

in 1841. In 1866, he was elected a foreign member of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences ( sv, Kungliga Vetenskapsakademien) is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special ...

. His final position was the

Master of the Mint Master of the Mint is a title within the Royal Mint given to the most senior person responsible for its operation. It was an important office in the governments of Scotland and England, and later Great Britain and then the United Kingdom, between ...

, where he stayed from 1855 until his death. He was the last person to hold that position: afterwards the post was amalgamated into the

Chancellor of the Exchequer The chancellor of the Exchequer, often abbreviated to chancellor, is a senior minister of the Crown within the Government of the United Kingdom, and head of His Majesty's Treasury. As one of the four Great Offices of State, the Chancellor is ...

while all the actual responsibilities were transferred to the Deputy Master. He died in

Gordon Square Gordon Square is a public park square in Bloomsbury, London, England. It is part of the Bedford Estate and was designed as one of a pair with the nearby Tavistock Square. It is owned by the University of London. History and buildings The ...

in London but his body was returned to Glasgow for burial in the family plot at

Glasgow Cathedral Glasgow Cathedral ( gd, Cathair-eaglais Ghlaschu) is a parish church of the Church of Scotland in Glasgow, Scotland. It is the oldest cathedral in mainland Scotland and the oldest building in Glasgow. The cathedral was the seat of the Archbisho ...

Publications

*''On the Law of Diffusion of Gases'' (1833)

Scientific works

Thomas Graham is known for his studies on the behaviour of gases, which resulted in his formulation of two relationships, both since becoming known as "Graham's Laws," the first regarding gas

, and the second regarding gas

effusion In physics and chemistry, effusion is the process in which a gas escapes from a container through a hole of diameter considerably smaller than the mean free path of the molecules. Such a hole is often described as a ''pinhole'' and the escape ...

. In the former case, Graham deduced that when measured repeatedly under the same conditions of pressure and temperature, the rate of diffusive mixing of a gas is inversely proportional to the square root of its density, and given the relationship between

density Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...

and

molar mass In chemistry, the molar mass of a chemical compound is defined as the mass of a sample of that compound divided by the amount of substance which is the number of moles in that sample, measured in moles. The molar mass is a bulk, not molecular, p ...

, also inversely proportional to the square root of its

. In the same way, in the latter case, regarding

of a gas through a pin hole in to a vacuum, Graham deduced that the rate of

of a gas is inversely proportional to the square root of its molar mass. These two are sometimes referred to as a combined law (describing both phenomena). In applied areas, Graham also made fundamental discoveries related to dialysis, a process used in research and industrial settings, as well as in modern health care. Graham's study of

colloids A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others extend ...

resulted in his ability to separate colloids and crystalloids using a so-called "dialyzer", using technology that is a rudimentary forerunner of technology in modern

kidney dialysis Kidney dialysis (from Greek , , 'dissolution'; from , , 'through', and , , 'loosening or splitting') is the process of removing excess water, solutes, and toxins from the blood in people whose kidneys can no longer perform these functions natura ...

machines. These studies were foundational in the field known as

, and Graham is credited as one of its founders. He also proposed the association theory which claimed that the substances such as

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...

starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets ...

that we now know are polymers are composed from smaller molecules hold together by unknown forces. It remained the most popular explanation until Hermann Staudinger's

macromolecular A macromolecule is a very large molecule important to biophysical processes, such as a protein or nucleic acid. It is composed of thousands of covalently bonded atoms. Many macromolecules are polymers of smaller molecules called monomers. The ...

theory of 1920s.

Honours, activities, and recognition

* Elected an Honorary Fellow of the

(1828) receiving its

for 1831–33 *

Fellow of the Royal Society Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the judges of the Royal Society of London to individuals who have made a "substantial contribution to the improvement of natural science, natural knowledge, incl ...

(1836) * First President of the

(1841) *

Royal Medal The Royal Medal, also known as The Queen's Medal and The King's Medal (depending on the gender of the monarch at the time of the award), is a silver-gilt medal, of which three are awarded each year by the Royal Society, two for "the most important ...

of the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

(1837 and 1863) * Honorary doctorate (DCL) from 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 ...

(1853) *

Copley Medal The Copley Medal is an award given by the Royal Society, for "outstanding achievements in research in any branch of science". It alternates between the physical sciences or mathematics and the biological sciences. Given every year, the medal is t ...

of the Royal Society (1862) * Prix Jecker of the Paris Academy of Sciences (1862) * A statue of Graham, sculpted by

William Brodie William Brodie (28 September 1741 – 1 October 1788), often known by his title of Deacon Brodie, was a Scottish cabinet-maker, deacon of a trades guild, and Edinburgh city councillor, who maintained a secret life as a housebreaker, partly fo ...

George Square George Square ( gd, Ceàrnag Sheòrais) is the principal civic square in the city of Glasgow, Scotland. It is one of six squares in the city centre, the others being Cathedral Square, St Andrew's Square, St Enoch Square, Royal Exchange S ...

in Glasgow was erected by the city in 1872George Square Thomas Graham Statue

Historic Environment Scotland Historic Environment Scotland (HES) ( gd, Àrainneachd Eachdraidheil Alba) is an executive non-departmental public body responsible for investigating, caring for and promoting Scotland's historic environment. HES was formed in 2015 from the mer ...

* The

Royal College of Science and Technology The Royal College of Science and Technology was a higher education college that existed in Glasgow, Scotland between 1887 and 1964, and is the predecessor institution of the University of Strathclyde. Its main building on George Street now serve ...

(the successor of Anderson's Institution, where Graham once worked, which ultimately became the

University of Strathclyde The University of Strathclyde ( gd, Oilthigh Shrath Chluaidh) is a public research university located in Glasgow, Scotland. Founded in 1796 as the Andersonian Institute, it is Glasgow's second-oldest university, having received its royal chart ...

), named its new Chemistry building the ''Thomas Graham Building'' in 1962. * The headquarters of the

Royal Society of Chemistry The Royal Society of Chemistry (RSC) is a learned society (professional association) in the United Kingdom with the goal of "advancing the chemistry, chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Ro ...

Cambridge Cambridge ( ) is a university city and the county town in Cambridgeshire, England. It is located on the River Cam approximately north of London. As of the 2021 United Kingdom census, the population of Cambridge was 145,700. Cambridge bec ...

, England is named ''Thomas Graham House''

References

External links