Posted by: Glow-worm PJ4 JUN 2010
5 June 2010 is the 250th anniversary of the birth of Johan Gadolin, widely regarded as Finland’s most famous scientist. He was born in the town of Åbo (now Turku), then part of Sweden, into a family of scientists, politicians and clergymen. His father was a professor of physics and theology and later became bishop of Åbo. His maternal grandfather, Johan Brovallius, was also a professor of physics and a friend of Linnaeus.
Gadolin studied chemistry at university in Uppsala and went on to be appointed professor of chemistry at the University of Åbo in 1797. He held the post until his retirement in 1822 and died on 15 August 1852.
Gadolin made a number of contributions to chemistry. By 1791 he had published papers on specific heat, as well as the latent heat of steam. He established the composition of Prussian blue, and used this to suggest the ferricyanide titration of ferrous iron, a volumetric analysis that preceded Gay-Lussac’s classic work by 40 years.
He was an innovative educator, opening up his laboratory to students, who participated in experiments rather than being mere spectators.
In 1791, revisiting work his father had started on the development of condensers, he improved the design and developed the “counter-current principle”, in which the cooling water in the jacket was made to flow uphill, greatly increasing the effectiveness of the condenser. This principle was adopted by the German chemist Liebig, and Gadolin’s condenser became known in Germany as the Liebig condenser.
But it was the discovery of the element yttrium that brought Gadolin fame in his lifetime. In the early 1790s he analysed a black mineral found in a feldspar quarry in the Swedish village of Ytterby, near Stockholm. He initially thought that what he was analysing was a new element, but it was in fact yttrium oxide. The element itself was eventually confirmed, the first in the so-called rare earth or lanthanide series.
When, in 1880, the French chemist Galissard de Marignac discovered a new element in a sample of the rare earth metal erbium, he named it gadolinium, the first element to be named after a person.
Gadolin also took a keen interest in politics, and was influential in bringing about the separation of the province of Finland from Sweden.