Johan Gadolin
Encyclopedia
Johan Gadolin was a Finnish chemist
Chemist
A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...
, physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
and mineralogist. Gadolin discovered the chemical element
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
yttrium
Yttrium
Yttrium is a chemical element with symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and it has often been classified as a "rare earth element". Yttrium is almost always found combined with the lanthanides in rare earth minerals and is...
. He is also considered the founder of Finnish chemistry
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
research, as the second holder of the Chair of Chemistry
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
at the Royal Academy of Turku.
Early life
Johan Gadolin was born in TurkuTurku
Turku is a city situated on the southwest coast of Finland at the mouth of the Aura River. It is located in the region of Finland Proper. It is believed that Turku came into existence during the end of the 13th century which makes it the oldest city in Finland...
, Finland (then a part of Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
), as the son of Jakob Gadolin
Jakob Gadolin
Jakob Gadolin was a Finnish Lutheran bishop, professor of physics and theology, politician and statesman....
. He began to study mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
at the Royal Academy of Turku when he was fifteen. Soon he found mathematics too laborious and changed his major to chemistry. In 1779 Gadolin moved to Uppsala University
Uppsala University
Uppsala University is a research university in Uppsala, Sweden, and is the oldest university in Scandinavia, founded in 1477. It consistently ranks among the best universities in Northern Europe in international rankings and is generally considered one of the most prestigious institutions of...
where he was taught by Torbern Bergman
Torbern Bergman
Torbern Olof Bergman was a Swedish chemist and mineralogist noted for his 1775 Dissertation on Elective Attractions, containing the largest chemical affinity tables ever published...
.
In 1790, he was elected a member of the Royal Swedish Academy of Sciences
Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences or Kungliga Vetenskapsakademien is one of the Royal Academies of Sweden. The Academy is an independent, non-governmental scientific organization which acts to promote the sciences, primarily the natural sciences and mathematics.The Academy was founded on 2...
.
Chemistry
Gadolin became famous when he discovered the first rare earth elementRare earth element
As defined by IUPAC, rare earth elements or rare earth metals are a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides plus scandium and yttrium...
. In 1792 Gadolin received a sample of black, heavy mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
found in a quarry
Quarry
A quarry is a type of open-pit mine from which rock or minerals are extracted. Quarries are generally used for extracting building materials, such as dimension stone, construction aggregate, riprap, sand, and gravel. They are often collocated with concrete and asphalt plants due to the requirement...
in the Swedish village Ytterby
Ytterby
Ytterby is a village on the Swedish island of Resarö, in Vaxholm Municipality in the Stockholm archipelago.The name of the village means "outer village", implying that its location is its most noteworthy feature....
near Stockholm
Stockholm
Stockholm is the capital and the largest city of Sweden and constitutes the most populated urban area in Scandinavia. Stockholm is the most populous city in Sweden, with a population of 851,155 in the municipality , 1.37 million in the urban area , and around 2.1 million in the metropolitan area...
. By careful experiments, he isolated a rare earth oxide which was later named yttria. He also isolated in the same study yttrium trihydroxide. Yttria, or yttrium oxide
Yttrium(III) oxide
Yttrium oxide is Y2O3. It is an air-stable, white solid substance. Yttrium oxide is used as a common starting material for both materials science as well as inorganic compounds.-Materials science:...
, was the first known rare earth metal compound — at that time, it was regarded as an element. The work was published in 1794.
The mineral that Gadolin examined was named gadolinite
Gadolinite
Gadolinite, sometimes also known as Ytterbite, is a silicate mineral which consists principally of the silicates of cerium, lanthanum, neodymium, yttrium, beryllium, and iron with the formula 2FeBe2Si2O10...
in 1800. The element gadolinium
Gadolinium
Gadolinium is a chemical element with the symbol Gd and atomic number 64. It is a silvery-white, malleable and ductile rare-earth metal. It is found in nature only in combined form. Gadolinium was first detected spectroscopically in 1880 by de Marignac who separated its oxide and is credited with...
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 vividly described the disproportionation
Disproportionation
Disproportionation, also known as dismutation is used to describe a specific type of redox reaction in which a species is simultaneously reduced and oxidized so as to form two different products....
reaction:
- 2 Sn(II) Sn(0) + Sn(IV).
Gadolin also studied specific heats and latent heat
Latent heat
Latent heat is the heat released or absorbed by a chemical substance or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. The term was...
s in 1787–92. This thermochemical work was very precise.
One of his latest studies was the chemical analysis of the Chinese alloy pak tong (alpacca, German silver) in 1810 and 1827.
Gadolin became the professor of chemistry at the Royal Academy of Turku
Turku
Turku is a city situated on the southwest coast of Finland at the mouth of the Aura River. It is located in the region of Finland Proper. It is believed that Turku came into existence during the end of the 13th century which makes it the oldest city in Finland...
in 1797. He was one of the first chemists who gave laboratory exercises to students. He even allowed the students to use his private laboratory. Gadolin wrote the first anti-phlogiston chemistry textbook in the Nordic countries
Nordic countries
The Nordic countries make up a region in Northern Europe and the North Atlantic which consists of Denmark, Finland, Iceland, Norway and Sweden and their associated territories, the Faroe Islands, Greenland and Åland...
.
He was close friends with Johan Gottlieb Gahn
Johan Gottlieb Gahn
Johan Gottlieb Gahn was a Swedish chemist and metallurgist who discovered manganese in 1774.Gahn studied in Uppsala 1762-1770 and became acquainted with chemists Torbern Bergman och Carl Wilhelm Scheele...
and Carl Wilhelm Scheele
Carl Wilhelm Scheele
Carl Wilhelm Scheele was a German-Swedish pharmaceutical chemist. Isaac Asimov called him "hard-luck Scheele" because he made a number of chemical discoveries before others who are generally given the credit...
.
Gadolin is also famous for publishing one of the earliest examples of counter-current condensers, today usually referred to as Liebig condensers.