para quitarle el polvo William Ramsay Jaime Wisniak* abstract (William Ramsay) William Ramsay (1852-1916) was awarded the 1904 Nobel Prize for Chemistry, “in recognition of his services in the discovery of the inert gaseous elements in air, and his determination of their place in the periodic system.” In addition, he made significant contributions in the fields of organic chemistry, thermodynamics, and radioactive processes, identifying the gases released during the transmutation of elements such as thorium and radium. key words: boiling point, PVT behavior, surface tension, inert gases, argon, radioactivity. Resumen to John Ferguson (1837-1916) at the University of Glasgow. William Ramsay (1852-1916) recibió el Premio Nobel en Afterwards he took over the chemistry chair in University Química (1904) por “su descubrimiento de los gases inertes College, Bristol, and in 1881, he was appointed principal of en el aire y la determinación de su lugar en la Tabla Periódica.” the College. In 1887 Ramsay succeeded Alexander William- Hizo además, importantes contribuciones en las áreas de son (1824-1904) in the chair of chemistry and he remained química organica, termodinámica, y procesos radioactivos, there during the rest of his active academic life (Moore, identificando los gases desprendidos durante la transmutación 1918). de elementos como el torio y el radio. In August 1881 Ramsay married Margaret Buchanan. They had two children. Life and career In 1900 Ramsay was appointed adviser to the Indian Gov- William Ramsay was born in Glasgow, Scotland, October 2, ernment on the question of university and technical educa- 1852, and died in Hazlemere, Buckinghamshire, on 22 July tion in connection with the bequest of Jamsetji Nusserwanji 1916). He was the only child of Catherine Robertson and Tata (1839-1904) who had left nearly half-a-million sterling William Ramsay, a civil engineer and businessman (Moore, to build and endow a university. This institution was started 1918; Collie, 1917). in Bangalore and eventually became the Indian Institute of From his fourth to his tenth year William Ramsay went to Science (Collie, 1917). an elementary school and then to the Glasgow Academy. Af- Ramsay’s researches on the rare gases brought him inter- terwards (1866) he matriculated at the University of Glas- national fame and many honors were conferred on him by gow where he also attended the chemistry lectures of John universities and learned societies throughout the world. The Ferguson (1837-1916) and the physics lectures of William most important recognition was the 1904 Nobel Prize for Thomson, (Lord Kelvin, 1824-1907). In May 1869 he en- chemistry “in recognition of his services in the discovery of tered the laboratory of Robert Rattray Tatlock (1855-1950), the inert gaseous elements in air, and his determination the Glasgow city analyst. During the winter he attended lec- of their place in the periodic system.” tures on chemistry in the university and for six months he worked in Lord Kelvin’s laboratory (Collie, 1917; Travers, Scientific contribution 1956). Ramsay was a prolific writer; he published more than 300 After the Franco-Prussian work he worked for a short time papers and 15 books. Among the latter we can mention Argon under Robert Wilhelm Bunsen (1811-1899) in Heidelberg a New Constituent of the Atmosphere, written with Lord Ray- and thereafter he transferred to the University of Tübingen to leigh (Rayleigh and Ramsay, 1895), A System of Inorganic study and work under Rudolf Fittig (1835-1910). There he stud- Chemistry (Ramsay, 1891b), Theoretical Modern Chemistry ied platinum-ammonium compounds and the properties and (Ramsay, 1900a), Introduction to the Study of Physical Chemis- reactions of the toluic acids (Böttinger and Ramsay, 1874ab). try (Ramsay, 1900b), and Experiments in Radio-Activity and In 1873 he obtained his Ph.D. and returned to Glasgow to the Production of Helium from Radium (Ramsay and Soddy, work first as assistant to Georg Bischof (1834-1906) and then 1904b), and Stoichiometry, (Ramsay, 1908b). The research activities of Ramsay may be classified into three general categories: (1) Pure organic and physico-organic chemistry, (2) Critical states of liquids and vapors and dis- *Department of Chemical Engineering, Ben-Gurion University covery of the inert gases and study of their properties, and of the Negev (3) Researches in radioactivity and allied physico-chemical Beer-Sheva, Israel 84105 problems. E-Mail: [email protected] octubre de 2008 • educación química para quitarle el polvo 303 wisniak.indd 303 23/11/2008 01:25:46 p.m. Chemistry Young, 1885abc) developed an important expression relating Ramsay’s first academic papers were on a new antimony the boiling points of two pure substances, which may be de- phosphide with a formula SbP (Ramsay, 1874a), on the prop- rived from the integrated Clausius-Clapeyron equation: erties and methods of preparation of hydrogen persulfide T RT ∆H (1) (Ramsay, 1874b), on the preparation of sodium ethylthiosul- 1=−+11(cc) ∆21∆ fate and proof of the constitutional formula for sodium dithi- THH222 onate and the reaction that takes place when this compound Assuming that both compounds have also the same vapor is heated with phosphorus pentachloride (Ramsay, 1875), on at the temperatures T1′ and T2′, then it must be that the analysis of a bismuth mineral carrying cobalt and nickel TT′ (2) (Ramsay, 1876a), and on the dehydration of hydrates (Ram- 11−=cT() − T′ ′ 11 say, 1877). TT22 His early chemical work was mainly concerned with or- where c is a constant given by ganic chemistry, and was initially based on a large collection R (3) of pyridine bases left at the University of Glasgow by Thomas c=−() cc ∆ 21 Anderson (1819-1874; discoverer of pyridine). Ramsay used H2 these chemicals to synthesize by oxidation a variety of pyri- Ramsay and Young reported the values of the constant c dinic acids as well as pyridine itself from hydrocyanic acid for 30 different pairs of substances (Ramsay and Young, and acetylene (Ramsay, 1876b). He published several papers 1885b), including such systems as water + ethanol, aniline + on the carboxylic acids resulting from oxidation of the pyri- water, water + oxygen, and ammonium chloride + water, and dines, demonstrating their relationship to the benzene car- indicated that it has a very small value (<2×10–4) and for boxylic acids. Together with John Gray McKendrick (1841- chemically similar substances (like water and ethanol) it is 1926), the professor of physiology, he investigated the almost zero. The last case corresponds to physiological action of various anesthetics (Coats et al., 1879), TT (4) and with James Johnston Dobbie, (1852-1924), quinine and 12==constant TT′′ its decomposition products, and then the decomposition of 12 allied alkaloids, quinidine (conquinine), cinchonine and cin- In other words, the ratio of the absolute temperatures at chonidine by oxidation with permanganate (Moore, 1918; which two substances boil under the same pressure is constant. Ramsay and Dobbie, 1878; Dobbie and Ramsay 1879). Curiously, in all their publications related to the boiling Ramsay then begun to study physico-chemical problems temperature of pure compounds, Ramsay and Young made related to organic chemistry, for example, the heat of forma- no reference to a very important paper on the subject pub- tion of aniline, picoline, toluidine, glycerin and other com- lished by Karl Eugen Dühring (1833-1921), almost ten years pounds (Ramsay, 1879b), the molecular volumes of the ben- before (Dühring, 1878), in which he showed that plotting zene, naphthalene, anthracite, and phenanthrene series the boiling point of a substance against the boiling point of (Ramsay, 1881a), the volumes of sodium and phosphorus at water at the same pressure yielded a straight line, that is their boiling points (Ramsay, 1879a; Ramsay and Mason, TT− ′ 11= q (5) 1881), and the atomic volume of nitrogen (Ramsay 1881b; TT− ′ Moore, 1918). 22 In 1884 he published a paper on the halogen compounds where T1′ and T2′, are the boiling points of one substance at of selenium in which he compared the stability of the halo- two different pressures, T2 and T2′, are the corresponding boil- gen compound of selenium with those of sulfur by measuring ing points of a second substance (water in this case), and q is the degree of disassociation caused by increased temperature a constant that is the slope of the line (Dühring’s rule). (Evans and Ramsay, 1884). With Sidney Young (1857-1937) In 1873, James Thomson discussed his findings on the be- he studied the decomposition of ammonia by heat, paying havior of a pure substance in the P-T domain (Thomson, special attention to the temperature at which decomposition 1873), where the three phase-change curves, solid-gas, solid- took place and to the influence of the material of the vessel or liquid, and liquid-gas, yielded three continuous curves, tube containing the gas (Ramsay and Young, 1884d). Ramsay which seemed to cross each other at one common point, which was one of the first scientists to offer a plausible explanation Thomson named triple point. The gas-liquid curve, named for Brownian (pedectic) movement (Ramsay, 1892). by Thomson the boiling curve, separated the regions of the plane corresponding to the ordinary liquid and those corre- Thermodynamics sponding to the ordinary gaseous state. Andrews (Andrews, Many different formulas and representations have been deve- 1869, 1876) had already demonstrated that this separating loped for the dependence of the vapor pressure with tempe- boundary came to an end at a point, which he called the crit- rature for pure liquids and their mixtures. ical point, and that the transition from any liquid state to any Between 1885 and 1886 Ramsay and Young (Ramsay and gaseous state could be gradually effected by an infinite variety 304 para quitarle el polvo educación química • octubre de 2008 wisniak.indd 304 23/11/2008 01:25:46 p.m.