Jöns Jakob Berzelius

Infobox_Scientist
name = J. J. Berzelius

|225px
caption = Jöns Jacob Berzelius (1779-1848)
birth_date = birth date|1779|8|20|df=y
birth_place = Väversunda, Östergötland, Sweden
death_date = death date|1848|8|7|df=y (aged 68)
death_place = Stockholm, Sweden
residence = Sweden
nationality = Swedish
field = Chemist
work_institution = Karolinska Institute
alma_mater = Uppsala University
doctoral_advisor = Johann Afzelius
doctoral_students = James Finlay Weir Johnston
Heinrich Rose
known_for = Law of constant proportions
Chemical notation
Silicon
Selenium
Thorium
Cerium
prizes =
religion =
footnotes =

Friherre Jöns Jacob 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. [cite encyclopedia
title = Jöns Jacob Berzelius
encyclopedia = Encyclopædia Britannica Online
url = http://www.britannica.com/EBchecked/topic/62958/Jons-Jacob-Berzelius
accessdate = 2008-08-03]

Career

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.

Law of Definite Proportions

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 favour of the atomic theory proposed by John Dalton: 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—such as O for oxygen, or Fe for iron—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 (H²O).

Discovery of Elements

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).

Biology

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 with such leading scientists as Mulder, Claude Louis Berthollet, Humphry Davy, Friedrich Wöhler and Eilhard Mitscherlich).

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.

Further reading

* A biography on "Jac. Berzelius - his life and work" was written by J. Erik Jorpes and published in 1966 and 1970 (originally in Swedish, first published in 1949).

* DSB
first=Henry
last=Leicester
title=Berzelius, Jöns Jacob
volume=2
pages=90-97

References

*cite journal
title = Jöns Jacob Berzelius A Guide to the Perplexed Chemist
author = Jaime Wisniak
journal = The Chemical Educator
year = 2000
volume = 5
issue = 6
pages = 343–350
doi = 10.1007/s00897000430a
*cite journal
title = Zum 100. Todestag von Jöns Jakob Berzelius am 7. August 1948
author = Paul Walden
journal = Zeitschrift Naturwissenschaften
volume = 34
issue = 11
pages = 321–327
year = 1947
url =
doi = 10.1007/BF00644137

External links

* [http://runeberg.org/authors/jjberzel.html Publications] - at Project Runeberg
*gutenberg author|id=Jöns_Jacob_Berzelius|name=Jöns Jacob Berzelius

Persondata
NAME= Berzelius, J. J.
ALTERNATIVE NAMES=
SHORT DESCRIPTION= Chemist
DATE OF BIRTH= 20 August 1779
PLACE OF BIRTH= Väversunda, Östergötland, Sweden
DATE OF DEATH= 7 August 1848
PLACE OF DEATH= Stockholm, Sweden