Jöns Jakob Berzelius

Jöns Jakob Berzelius (20 August 1779 – 7 August 1848) was a Swedish chemist. He invented the modern chemical notation. Berzelius, John Dalton and Antoine Lavoisier are said to be the fathers of modern chemistry.

Berzelius was born in Linköping in Östergötland in Sweden. He graduated from Uppsala University as a physician. He became a professor in medicine and surgery at the Stockholm School of Surgery in 1807. In 1810, this became part of Medico-Chirurgiska Institutet (later the Karolinska Institute) and Berzelius became a professor of chemistry and pharmacy.

Not long after going to Stockholm, Berzelius wrote a chemistry textbook for his medical students. While doing experiments for the textbook, he found that inorganic compounds are made of different elements in proportion by weight. Based on this, in 1828, he created a table of relative atomic weights. On this table, oxygen was set to 100. The table had all of the elements known at the time. This work gave evidence of the atomic hypothesis that 
chemical compounds are made of atoms combined in whole number amounts. 

In order to help his experiments, Berzelius created a system of chemical notation. In this notation, the elements were given simple written labels, for example, O for oxygen, or Fe for iron. The proportions of the elements was shown by numbers. This is the same basic system used today. The only difference is that instead of the subscript number used today (for example, H2O), Berzelius used a superscript.

Berzelius found the chemical elements silicon, selenium, thorium, and cerium. Students working in Berzelius laboratory also found lithium and vanadium.

Berzelius was the first person to show the difference between organic compounds (those made with carbon), and inorganic compounds. He helped Gerhardus Johannes Mulder in his analysis of organic compounds such as coffee, tea and many proteins. The term "protein" itself was created by Berzelius, after Mulder noticed that all proteins seemed to have the same formula and might be made of a single type of a (very large) molecule.

Berzelius wrote a great deal. He helped many leading scientists (such as Mulder, Claude Louis Berthollet, Humphry Davy, Friedrich Wöhler and Eilhard Mitscherlich), and many less-notable scientists.

 Summary of achievements 
Law of definte proportions
Chemical formula
Discovered chemical elements
Recognised organic compounds; named proteins.

 Sources 
Crosland M.P. 1962. Historical studies in the language of chemistry.  Chapter 4: The symbols of Berzelius. London: Heinemann.
von Meyer, Ernst 1906. A history of chemistry from the earliest times to the present day. p212 et seq: Berzelius: a survey of his work. London: Macmillan.
Partington J.R. 1964 History of chemistry, vol 4. London: Macmillan; pp. 142–77.
Leicester, Henry 1970–80. Berzelius, Jöns Jacob. In Dictionary of scientific biography, vol 2, p90–97. New York: Scribners. ISBN 978-0-684-10114-9

Category:1779 births
Category:1848 deaths
Category:Swedish chemists