Jöns Jakob Berzelius

Friherre Jöns Jakob Berzelius (20 August 1779 – 7 August 1848) was a Swedish chemist. He invented the modern chemical notation, and is together with John Dalton, Antoine Lavoisier, and Robert Boyle considered a father of modern chemistry.

Berzelius was born at Väversunda in Östergötland in Sweden. He lost both his parents at an early age. He was taken care of by relatives in Linköping where he attended the school today known as Katedralskolan. Thereafter he enrolled at the Uppsala University where he learned the profession of medical doctor from 1796 to 1801. He was taught chemistry by Anders Gustaf Ekeberg, the discoverer of tantalum. He worked as apprentice in a pharmacy and with a physician in the Medevi mineral springs. During this time he conducted analysis of the spring water. For his medical studies he examined the influence of galvanic current on several diseases. He worked as physician near Stockholm until the mine owner Wilhelm Hisinger discovered his analytical abilities and provided him with a laboratory.

In 1807 Berzelius was appointed professor in chemistry and pharmacy at the Karolinska Institute.

Not long after arriving to Stockholm he wrote a chemistry textbook for his medical students, from which point a long and fruitful career in chemistry began. While conducting experiments in support of the textbook he discovered the law of constant proportions, which showed that inorganic substances are composed of different elements in constant proportions by weight. Based on this, in 1828 he compiled a table of relative atomic weights, where oxygen was set to 100, and which included all of the elements known at the time. This work provided evidence in favor of the atomic theory: that inorganic chemical compounds are composed of atoms combined in whole number amounts. In discovering that atomic weights are not integer multiples of hydrogen's, Berzelius also disproved Prout's hypothesis that elements are built up from atoms of hydrogen.

In order to aid his experiments, he developed a system of chemical notation in which the elements were given simple written labels&mdash;such as O for oxygen, or Fe for iron&mdash;with proportions noted by numbers. This is the same basic system used today, the only difference being that instead of the subscript number used today (e.g., H2O), Berzelius used a superscript.

Berzelius is credited with identifying the chemical elements silicon, selenium, thorium, and cerium. Students working in Berzelius' laboratory also discovered lithium, and vanadium.

Berzelius is also credited with originating the chemical terms "catalysis", "polymer", "isomer" and "allotrope", although his original definitions differ dramatically from modern usage. For example, he coined the term "polymer" in 1833 to describe organic compounds which shared identical empirical formulas but differed in overall molecular weight, the larger of the compounds being described as "polymers" of the smallest. According to this (now obsolete) definition, glucose (C6H12O6) would be a polymer of formaldehyde (CH2O).

Berzelius had an effect on biology as well. He was the first person to make the distinction between organic compounds (those containing carbon), and inorganic compounds. In particular, he advised Gerhardus Johannes Mulder in his elemental analyses of organic compounds such as coffee, tea and various proteins. The term "protein" itself was coined by Berzelius, after Mulder observed that all proteins seemed to have the same empirical formula and might be composed of a single type of (very large) molecule. Berzelius proposed the name because the material seemed to be the primitive substance of animal nutrition that plants prepare for the herbivores.

Berzelius was a prolific correspondent, advising many leading scientists (such as Mulder, Claude Louis Berthollet, Humphry Davy, Friedrich Wöhler and Eilhard Mitscherlich), and fostering many less-notable scientists.

After denying the fact that chlorine is an element (which was proposed by Humphry Davy in 1810) for quite some time, the dispute was ended by the finding of iodine in 1813.



Berzeliusskolan, a school situated next to his alma mater Katedralskolan, is named for him.

In 1835 at the age of 56, he married Elisabeth Poppius, the 24-year old daughter of a Swedish cabinet minister.