density and molar mass, also inversely proportional to the square root of its molar mass. In the same way, in the latter case, regarding effusion of a gas through a pin hole in to a vacuum, Graham deduced that the rate of effusion 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 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 machines. These studies were foundational in the field known as colloid chemistry, and Graham is credited as one of its founders. He also proposed the association theory which claimed that the substances such as cellulose or starch 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 theory of 1920s. Honours, activities, and recognition Elected an Honorary Fellow of the Royal Society of Edinburgh (1828) receiving its Keith Medal for 1831–33 Fellow of the Royal Society (1836) First President of the Chemical Society of London (1841) Royal Medal of the Royal Society (1837 and 1863) Honorary doctorate (DCL) from the University of Oxford (1853) Copley Medal of the Royal Society (1862) Prix Jecker of the Paris Academy of Sciences (1862) A statue of Graham, sculpted by William Brodie in George Square in Glasgow was erected by the city in 1872 The Royal College of Science and Technology (the successor of Anderson's Institution, where Graham once worked, which ultimately became the University of Strathclyde), named its new Chemistry building the Thomas Graham Building in 1962. The headquarters of the Royal Society of Chemistry in Cambridge, England is named Thomas Graham House See also Graham's law Gaseous diffusion Dialysis Colloid Fick's laws of diffusion References External links Biography Obituary from Nature by A. W. Williamson Papers of Thomas Graham Records of Glasgow Mechanics' Institution / College of Science and Arts 1805 births 1869 deaths Scientists from Glasgow Scottish chemists Recipients of the Copley Medal Alumni of the University of Edinburgh People associated with the University of Strathclyde Masters of the