Johan Gadolin (5 June 176015 August 1852) was a

Finnish Finnish may refer to: * Something or someone from, or related to Finland * Culture of Finland * Finnish people or Finns, the primary ethnic group in Finland * Finnish language, the national language of the Finnish people * Finnish cuisine See also ...

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 t ...

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

and

mineralogist Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the proce ...

. Gadolin discovered a " new earth" containing the first rare-earth compound

yttrium Yttrium is a chemical element with the symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a " rare-earth element". Yttrium is almost always found in co ...

, which was later determined to be a

chemical element A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler sub ...

. He is also considered the founder of Finnish chemistry research, as the second holder of the Chair of Chemistry at the

Royal Academy of Turku The Royal Academy of Turku or the Royal Academy of Åbo ( sv, Kungliga Akademin i Åbo or ; la, Regia Academia Aboensis; fi, Turun akatemia) was the first university in Finland, and the only Finnish university that was founded when the country ...

(or ''Åbo Kungliga Akademi''). Gadolin was ennobled for his achievements and awarded the

Order of Saint Vladimir The Imperial Order of Saint Prince Vladimir (russian: орден Святого Владимира) was an Imperial Russian order established on by Empress Catherine II in memory of the deeds of Saint Vladimir, the Grand Prince and the Baptize ...

and the

Order of Saint Anna The Imperial Order of Saint Anna (russian: Орден Святой Анны; also "Order of Saint Anne" or "Order of Saint Ann") was a Holstein ducal and then Russian imperial order of chivalry. It was established by Karl Friedrich, Duke of Hol ...

Early life and education

Johan Gadolin was born in Åbo (Finnish name

Turku Turku ( ; ; sv, Åbo, ) is a city and former capital on the southwest coast of Finland at the mouth of the Aura River, in the region of Finland Proper (''Varsinais-Suomi'') and the former Turku and Pori Province (''Turun ja Porin lääni''; ...

), Finland (then a part of Sweden). Johan was the son of

Jakob Gadolin Jakob Gadolin (24 October 1719 – 26 September 1802) was a Swedish Lutheran bishop, professor of physics and theology, politician and statesman. Gadolin was born in Strängnäs, Sweden. In 1736, he studied at The Royal Academy of Turku (which l ...

, professor of physics and theology at Åbo. Johan began to study mathematics at the

(''Åbo Kungliga Akademi'') when he was fifteen. Later he changed his major to chemistry, studying with Pehr Adrian Gadd, the first chair of chemistry at Åbo. In 1779 Gadolin moved to

Uppsala University Uppsala University ( sv, Uppsala universitet) is a public research university in Uppsala, Sweden. Founded in 1477, it is the oldest university in Sweden and the Nordic countries still in operation. The university rose to significance during ...

. In 1781, he published his dissertation ''Dissertatio chemica de analysi ferri'' ("Chemical dissertation on the analysis of iron"), under the direction of

Torbern Bergman Torbern Olaf (Olof) Bergman (''KVO'') (20 March 17358 July 1784) was a Swedish chemist and mineralogist noted for his 1775 ''Dissertation on Elective Attractions'', containing the largest chemical affinity tables ever published. Bergman was the ...

. Bergman founded an important research school, and many of his students, including Gadolin,

Johan Gottlieb Gahn Johan Gottlieb Gahn (19 August 1745 – 8 December 1818) was a Swedish chemist and metallurgist who isolated manganese in 1774. Gahn studied in Uppsala 1762 – 1770 and became acquainted with chemists Torbern Bergman and Carl Wilhelm Scheele. 177 ...

, and

Carl Wilhelm Scheele Carl Wilhelm Scheele (, ; 9 December 1742 – 21 May 1786) was a Swedish German pharmaceutical chemist. Scheele discovered oxygen (although Joseph Priestley published his findings first), and identified molybdenum, tungsten, barium, hyd ...

, became close friends.

Career

Gadolin was fluent in Latin, Finnish, Russian, German, English and French in addition to his native Swedish. He was a candidate for the chair of chemistry at Uppsala in 1784, but Johann Afzelius was selected instead. Gadolin became an extraordinary professor at Åbo in 1785 (an unpaid position). Beginning in 1786, he made a chemical "grand tour" of Europe, visiting universities and mines in various countries. He worked with Lorenz Crell, editor of the journal ''Chemische Annalen'' in Germany, and with

Adair Crawford Adair Crawford FRS FRSE (174829 July 1795), a chemist and physician, was a pioneer in the development of calorimetric methods for measuring the specific heat capacity of substances and the heat of chemical reactions. In his influential 1779 bo ...

and

Richard Kirwan Richard Kirwan, LL.D, FRS, FRSE MRIA (1 August 1733 – 22 June 1812) was an Irish geologist and chemist. He was one of the last supporters of the theory of phlogiston. Kirwan was active in the fields of chemistry, meteorology, and geol ...

in Ireland. Gadolin was elected a member of the Royal Swedish Academy of Sciences in 1790. Gadolin became the ordinary professor of chemistry at the Royal Academy of

in 1797, after the death of Pehr Adrian Gadd. He retained the position until his retirement in 1822. He was one of the first chemists who gave laboratory exercises to students. He even allowed the students to use his private laboratory.

Chemical achievements

Gadolin made contributions in a variety of areas. Although he never visited France, he became a proponent of

Antoine Lavoisier Antoine-Laurent de Lavoisier ( , ; ; 26 August 17438 May 1794),
CNRS (

Nordic countries that questioned the theory of

phlogiston The phlogiston theory is a superseded scientific theory that postulated the existence of a fire-like element called phlogiston () contained within combustible bodies and released during combustion. The name comes from the Ancient Greek (''burni ...

and discussed the role of oxygen in combustion in a modern way.

Studies of heat

Gadolin studied the relationship of heat to chemical changes, in particular, the ability of different substances to absorb heat (

specific heat In thermodynamics, the specific heat capacity (symbol ) of a substance is the heat capacity of a sample of the substance divided by the mass of the sample, also sometimes referred to as massic heat capacity. Informally, it is the amount of heat t ...

) and the absorption of heat during state changes (

latent heat Latent heat (also known as latent energy or heat of transformation) is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process — usually a first-order phase transition. Latent heat can be underst ...

). This thermochemical work required extremely precise measurements. Gadolin published important papers on specific heat by 1784, and on the latent heat of steam in 1791. He demonstrated that the heat of ice was equal to the heat of snow, and published a standard set of heat tables.

Yttrium, the first rare-earth element

Gadolin became famous for his description of the first

rare-earth element The rare-earth elements (REE), also called the rare-earth metals or (in context) rare-earth oxides or sometimes the lanthanides ( yttrium and scandium are usually included as rare earths), are a set of 17 nearly-indistinguishable lustrous silv ...

. In 1792 Gadolin received a sample of black, heavy

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

found in a

quarry A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their envir ...

in a Swedish village

Ytterby Ytterby () is a village on the Swedish island of Resarö, in Vaxholm Municipality in the Stockholm archipelago. Today the residential area is dominated by suburban homes. The name of the village translates to "outer village". Ytterby is per ...

near Stockholm by

Carl Axel Arrhenius Carl Axel Arrhenius (29 March 1757 – 20 November 1824) was an officer in the Swedish army as well as an amateur geologist and chemist. He is best known for his discovery of the mineral ytterbite (later called gadolinite) in 1787. The disc ...

. By careful experiments, Gadolin determined that approximately 38% of the sample was a previously unknown "earth", an oxide which was later named

yttria Yttrium oxide, also known as yttria, is Y2 O3. It is an air-stable, white solid substance. The thermal conductivity of yttrium oxide is 27 W/(m·K). Uses Phosphors Yttria is widely used to make Eu:YVO4 and Eu:Y2O3 phosphors that give the red ...

. Yttria, or

yttrium oxide Yttrium oxide may refer to: * Yttrium(II) oxide, YO, a dark brown solid * Yttrium(III) oxide Yttrium oxide, also known as yttria, is Y2 O3. It is an air-stable, white solid substance. The thermal conductivity of yttrium oxide is 27 W/(m·K). ...

, was the first known rare-earth metal compound—at that time, it was not yet regarded as an element in the modern sense. His work was published in 1794. The mineral that Gadolin examined was named gadolinite in 1800. The element

gadolinium Gadolinium is a chemical element with the symbol Gd and atomic number 64. Gadolinium is a silvery-white metal when oxidation is removed. It is only slightly malleable and is a ductile rare-earth element. Gadolinium reacts with atmospheric oxygen ...

and its oxide gadolinia were named after Gadolin by its discoverers. In an earlier paper in 1788 Gadolin showed that the same element can show several oxidation states, in his case Sn(II) and Sn(IV) 'by combining itself with larger or smaller amounts of the calcinating substance'. He described the

disproportionation In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation states. More generally, the term can ...

reaction: :2 Sn(II) Sn(0) + Sn(IV).

Analytical chemistry

Having established the composition of Prussian blue, Gadolin suggested a method for precipitating ferrous iron as ferro ferricyanide, preceding the work of Gay-Lussac by forty years. Reports of many of Gadolin's chemical investigations appeared in German in Crell's ''Chemische Annalen für die Freunde der Naturlehre, Arzneygelahrheit, Haushaltungskeit und Manufacturen''. In 1825 he published ''Systema fossilium analysibus chemicis examinatorum secundum partium constitutivarum rationes ordinatorium'', a system of mineral classification based upon chemical principles. The introduction outlines Gadolin's theories, and the text presents mineral species in a systematic ordering. One of Gadolin's latest studies was the chemical analysis of the Chinese alloy '' pak tong'' in 1810 and 1827. Also known as alpacca or German silver, it was a less expensive silver substitute often containing copper, zinc, nickel, and tin. Gadolin is also famous for publishing one of the earliest examples of counter-current condensers. In 1791 he improved a condenser design of his father's by using the "counter-current principle". By requiring water coolant to flow uphill, the effectiveness of the condenser was increased. This principle was later used by

Justus Liebig Justus Freiherr von Liebig (12 May 1803 – 20 April 1873) was a German scientist who made major contributions to agricultural and biological chemistry, and is considered one of the principal founders of organic chemistry. As a professor at the ...

, in what is today usually referred to as a

Liebig condenser The Liebig condenser (, ) or straight condenser is a piece of laboratory equipment, specifically a condenser consisting of a straight glass tube surrounded by a water jacket. In typical laboratory operation, such as distillation, the condenser ...

Awards

Gadolin was knighted and is registered under number 245 in the

Finnish House of Nobility The House of Nobility either refers to the institution of the Finnish nobility or the palace of the noble estate. The Finnish nobility was until 1906 the first of the four estates of the realm. The Estate The estate of nobility existed fully st ...

. He was also awarded the

and the

. His heraldic device was:

Argent, on a bend Azure with two mullets Or between a rose Gules and crystals Proper.

Later life

Johan Gadolin married first, at age 35, Hedvig Tihleman, with whom he had nine children. After his wife's death he married, at age 59, Ebba Palander. Gadolin retired as professor emeritus in 1822 at age 62, a mandatory age of retirement. He moved to a country estate where he lived for another 30 years. He died in Mynämäki, Finland on 15 August 1852. The

Great Fire of Turku The Great Fire of Turku ( fi, Turun palo, sv, Åbo brand and russian: Пожар Або) was a conflagration in the city of Turku in 1827. It is still the largest urban fire in the history of Finland and the Nordic countries. The city had burned ...

of 1827 started in a bakery and damaged or destroyed much of the town of Åbo. Gadolin's laboratory and collection of minerals near the cathedral were destroyed.

References

{{DEFAULTSORT:Gadolin, Johan 1760 births 1852 deaths 18th-century chemists 18th-century Finnish people 19th-century chemists 19th-century Finnish people Corresponding members of the Saint Petersburg Academy of Sciences Discoverers of chemical elements Finnish chemists Finnish geologists Finnish mineralogists Members of the Royal Swedish Academy of Sciences People from Turku Rare earth scientists Swedish-speaking Finns Uppsala University alumni