Johan Gadolin

Johan Gadolin ( born June 5, 1760 Åbo (Finnish Turku ); † August 15, 1852 in Virmo (Finnish Mynämäki ) ) was a Finnish chemist. Gadolin discovered in 1794 the first chemical element from the group of rare-earth metals, of yttrium in the mineral Ytterbit and was one of the first supporters of Lavoisier's theory of combustion in Scandinavia.

Childhood and education

Johan Gadolin was born in a Finnish family of scholars. His father was a professor of physics and theology in the University of Turku. Later, this acted as a bishop in this city. Through his family, he was educated in his childhood with scientific topics, especially in physics and astronomy in conjunction. His grandfather Johan Browall possessed great merits as a professor of physics and as a bishop. Through him existed friendly relations of family to Carl Linnaeus. This environment Johan Gadolin early.

After school he started in 1775 at the Royal Academy of his native town to study in mathematics and physics, later moving to the chemistry lectures of Professor Pehr Adrian Gadd, who had the first chair of chemistry at the university since 1761. It is the oldest university in Finland. The experienced chemistry lectures him were too one-sided, as they are very oriented to practical applications and farming. His interests focused on theoretical questions and he felt the lectures increasingly unsatisfactory. Therefore Gadolin moved in 1779 to the University of Uppsala, and attended lectures at Torbern Olof Bergman. He also strengthened his studies in physics and mathematics. In the event free summers he traveled around in Sweden to improve its mineralogical and metallurgical skills. While studying in Uppsala is Gadolin and Scheele, who then established a lifelong friendship met. Supported by Bergman in 1781 he wrote a dissertation on the topic " De analysi ferri ". The following year he received his master's degree in philosophy with the theme " De problemate catenario ". Now began his important work on the theory of heat, which he later continued in Åbo (Finnish Turku ) and published in 1784. In 1783 he left the University of Uppsala and took an extraordinary professorship in his native city.

Scientific Work

His quest for further knowledge pursued Gadolin in the new role at the Royal Academy of Åbo by an almost two-year study trip in Europe. It began in 1786 and led through Denmark, Germany, Holland and England. Among his most important venues were Lüneburg, Helmstedt, the mining area in the Harz, Göttingen, Amsterdam, London and Dublin. During this trip and valuable experience especially information about the new chemical nomenclature were won for him. A particularly long after-effect relationship developed to the Göttingen chemist and mining engineer Lorenz von Crell. In London he worked on analytical studies on iron ores and this published his findings. This Gadolin expressed preliminary considerations for volumetric analysis in chemistry. The chemical industry in England was one of the destinations visited during his stay. With his friend, the Irish scholar Richard Kirwan, he undertook a trip to Ireland, which served primarily mineralogical studies. An article in the journal Chemical his friend Crell reports on the Irish travel impressions. With a wealth of experience Gadolin returns to his native Finnish and gives 1788 a treatise on the new nomenclature in chemistry out. It is dedicated to the meritorious work of Antoine Laurent de Lavoisier, Louis Bernard Guyton de Morveau, Antoine François de Fourcroy and Claude -Louis Berthollet. That brought him to the attention of those persons. A more intensive scientific exchange resulted in the sequence with Berthollet and Guyton de Morveau. His friend Crell wrote to him after his return: "You will bring the chemistry in Finland Bloom, I would not wonder at your talents and skills. " Now the professional development of Gadolin strengthened. First appointed in 1789 to the adjuncts, he came quickly in the qualifying professor. Even in the last years of his teacher Gadd he took lectures and after his death in 1787, the full professorship. Based on its rich experience, he changed the course content of the lesson and is now considered the true founder of scientific chemistry in Finland.

During his trip to Europe, he wrote a script for the phlogiston theory (1788 ). First, he still went out of the existence of phlogiston, but had knowledge of the role of oxygen in combustion. With this attachment Gadolin tried a mediating approach between the two opinion camps by his own theory. Finally, his concerns minderten against the views of Lavoisier and he joined as the first Scandinavian chemist the novel teachings on the incineration of. Consequently Gadolin wrote the first anti-inflammatory chemistry textbook in Swedish, published in 1798, entitled Introduction to Chemistry. It made ​​a decisive contribution to the diffusion of knowledge among the northern European scientists.

His language skills enabled a versatile communication with various key partners in Europe. Gadolin dominated addition to his native Finnish languages ​​Latin, German, English, French, Russian and Swedish. Among the correspondents were Joseph Banks, Torbern Olof Bergman, Claude Louis Berthollet, Adair Crawford, Lorenz Florenz Friedrich Crell, Johann Friedrich Gmelin, Louis Bernard Guyton de Morveau, Richard Kirwan, Martin Heinrich Klaproth, Antoine Laurent Lavoisier and Carl Wilhelm Scheele.

The discovery of yttrium

Its most well known scientific contribution in chemistry is the analysis of a black mineral from the Feldspatbruch Ytterby on the Swedish island Resarö, which was operated for the porcelain factory of Stockholm. There was in 1788 the collector and Swedish artillery officer Carl Axel Arrhenius, a hitherto unknown black mineral, which was described by Bengt Reinhold Geijer and Sven Rinman the first time and later was given the name Gadolinit. Gadolin received a sample of this mineral and examined it in detail for the period 1792-1793. He described this piece as a red feldspar, in which the black opaque mineral is embedded panel and kidney-shaped. The analysis result showed alumina, iron oxide and silica, and a larger proportion (38%) of an unknown oxide. On the assessment of his discovery, he was not quite sure and expressed his concerns in a letter to the secretary of the Swedish Academy of Sciences. The Swedish chemist Anders Gustaf Ekeberg confirmed with our own analysis in 1797, the results of gadolinium and thus the existence of an unknown Erdoxides. The discovered in these contexts element yttrium was later by Friedrich Wöhler (1824 ) and Carl Gustav Mosander (1842 ) isolated in metallic form.

In the Crellschen Chemical annals gadolinium manifested to his alleged discovery as follows: " From these properties one finds that this world in many ways with the Alaunerde, agrees, but in others with the lime that they are but also of beyden as also differs from other previously unknown kinds of soil. therefore seems to deserve a place among the simple earths, because the experiments has shown that the composition of suspect no other. now I do not dare even to suggest such a new invention because my little stock of the black stone type not allowed me to pursue the experiments according to my wishes. Ohnedem I also think that science should rather win if the several recently described by the sheath artists, new earths could be broken down into simpler constituents, as if the number the new simple earths is aggravated. "

In naming it temporarily gave different opinions. The mineral discovered called Ekeberg Yttersten and the unknown metal oxide yttria. From German mineralogists and chemists Gadolinit the terms and for the chemical substance Gadolinerde have been proposed. Eventually a compromise was. The mineral then transmits the name Gadolinit and the chemical element called yttrium.

The considerable importance of Gadolinschen studies with this mineral is the fact that as a consequence of multiple element discoveries were made in the rare-earth group of Scandinavian sites. In recognition of his great achievements was the concern of the name suggestion for a new item. The Swiss chemist Jean Charles de Galissard Marignac discovered in 1880 in an analytical study on the mineral Samarskite (formerly also Uranotantal, Yttroilmenit ) a new element by Paul Emile Lecoq de Boisbaudran received in 1886 the name gadolinium.

When the German chemist Johann Friedrich Gmelin died Gadolin received 1804 reputation to take over his professorship at the University of Göttingen. But his close ties to the homeland left him of this honorable vocation refrain.

Later years

During his university work Gadolin further developed theories to chemical proportions and affinities. They were but little attention due to minor editorial spread in Central Europe and supplanted by other researchers. In 1822 he went into retirement. Nevertheless, continued the scientific work in which he dealt with a system in the mineral kingdom Systema Fossilium. The basis for this work were under his responsibility considerably grown natural history collections at the university. Unfortunately, she received no more attention upon release.

In 1827 a major fire destroyed the city of Åbo, of which the University as well as significant portions of the collections were affected. This event ended the active scientific work of gadolinium. Then we moved the Finnish University to Helsingfors (now Helsinki). As a result of this loss, he lived in retirement on his two farms in Vichtis (now Vihti ) and Virmo (now Mynämäki ). In old age of 92 years he died on August 15, 1852.

Achievements and awards

In his native Finland, he profiled the chemistry education according to the latest scientific findings and led a regular practical work and laboratory exercises for students. This way of working was at that time in many other European universities not yet common practice.

According to him, the mineral are Gadolinit (1794 discovered by him) and named the element gadolinium. The name of the asteroid ( 2638 ) Gadolin reminded of him, as well as the Finnish astronomer Jacob Gadolin.

Memberships Johan Gadolin passed in:

• Royal Swedish Academy of Sciences, Stockholm
• Russian Academy of Sciences, St. Petersburg
• Royal Irish Academy, Dublin
• Member of the Leopoldina, since 1797

Scientific societies

• In Göttingen
• Uppsala
• Moscow ( Naturalists Society)
• Marburg ( Naturalists Society)