Jöns Jacob Berzelius
Jöns Jacob Berzelius was a Swedish chemist. Berzelius is considered, along with Robert Boyle, John Dalton, and Antoine Lavoisier, to be one of the founders of modern chemistry. Berzelius became a member of the Royal Swedish Academy of Sciences in 1808 and served from 1818 as its principal functionary. He is known in Sweden as the "Father of Swedish Chemistry". During his lifetime he did not customarily use his first given name, and was universally known simply as Jacob Berzelius.
Although Berzelius began his career as a physician, his enduring contributions were in the fields of electrochemistry, chemical bonding and stoichiometry. In particular, he is noted for his determination of atomic weights and his experiments that led to a more complete understanding of the principles of stoichiometry, which is the branch of chemistry pertaining to the quantitative relationships between elements in chemical compounds and chemical reactions and that these occur in definite proportions. This understanding came to be known as the "Law of Constant Proportions".
Berzelius was a strict empiricist, expecting that any new theory must be consistent with the sum of contemporary chemical knowledge. He developed improved methods of chemical analysis, which were required to develop the basic data in support of his work on stoichiometry. He investigated isomerism, allotropy, and catalysis, phenomena that owe their names to him. Berzelius was among the first to articulate the differences between inorganic compounds and organic compounds. Among the many minerals and elements he studied, he is credited with discovering cerium and selenium, and with being the first to isolate silicon and thorium. Following on his interest in mineralogy, Berzelius synthesized and chemically characterized new compounds of these and other elements.
Berzelius demonstrated the use of an electrochemical cell to decompose certain chemical compounds into pairs of electrically opposite constituents. From this research, he articulated a theory that came to be known as electrochemical dualism, contending that chemical compounds are oxide salts, bonded together by electrostatic interactions. This theory, while useful in some contexts, came to be seen as insufficient. Berzelius's work with atomic weights and his theory of electrochemical dualism led to his development of a modern system of chemical formula notation that showed the composition of any compound both qualitatively and quantitatively. His system abbreviated the Latin names of the elements with one or two letters and applied superscripts to designate the number of atoms of each element present in the compound. Later, chemists changed to use of subscripts rather than superscripts.
Biography
Early life and education
Berzelius was born in the parish of Väversunda in Östergötland in Sweden. His father Samuel Berzelius was a school teacher in the nearby city of Linköping, and his mother Elizabeth Dorothea Sjösteen was a homemaker. His parents were both from families of church pastors. Berzelius lost both his parents at an early age. His father died in 1779, after which his mother married a pastor named Anders Eckmarck, who gave Berzelius a basic education including knowledge of the natural world. Following the death of his mother in 1787, relatives in Linköping took care of him. There he attended the school today known as Katedralskolan. As a teenager, he took a position as a tutor at a farm near his home, during which time he became interested in collecting flowers and insects and their classification.Berzelius later enrolled as a medical student at Uppsala University, from 1796 to 1801. Anders Gustaf Ekeberg, the discoverer of tantalum, taught him chemistry during this time. He worked as an apprentice in a pharmacy, during which time he also learned practical matters in the laboratory such as glassblowing. On his own during his studies, he successfully repeated the experimentation conducted by Swedish chemist Carl William Scheele which led to Scheele's discovery of oxygen. He also worked with a physician in the Medevi mineral springs. During this time, he conducted an analysis of the water from this source. Additionally as part of his studies, in 1800, Berzelius learned about Alessandro Volta's electric pile, the first device that could provide a constant electric current. He constructed a similar battery for himself, consisting of alternating disks of copper and zinc, and this was his initial work in the field of electrochemistry.
As thesis research in his medical studies, he examined the influence of galvanic current on several diseases. This line of experimentation produced no clear-cut evidence for such influence. Berzelius graduated as a medical doctor in 1802. He worked as a physician near Stockholm until the chemist and mine-owner Wilhelm Hisinger recognized his abilities as an analytical chemist and provided him with a laboratory.
Academic career
In 1807, Berzelius was appointed professor in chemistry and pharmacy at the Karolinska Institute. Between 1808 and 1836, Berzelius worked together with Anna Sundström, who acted as his assistant and was the first female chemist in Sweden.In 1808, he was elected a member of the Royal Swedish Academy of Sciences. At this time, the Academy had been stagnating for several years, since the era of romanticism in Sweden had led to less interest in the sciences. In 1818, Berzelius was elected the Academy's secretary and held the post until 1848. During Berzelius's tenure, he is credited with revitalising the Academy and bringing it into a second golden era. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1822. In 1827, he became correspondent of the Royal Institute of the Netherlands, and in 1830 associate member.
In 1837, he was elected a member of the Swedish Academy, on chair number 5.
Temperance movement
Berzelius was active in the temperance movement. Along with,, Anders Retzius, Samuel Owen, George Scott, and others, he was one of the founders of the Svenska nykterhetssällskapet in 1837 and its first chairman. Berzelius wrote the foreword to one of works on the topic, of which 50,000 copies were printed.Later life
Through much of his life, Berzelius suffered various medical ailments. These included recurrent migraine headaches and then later on he suffered from gout. He also had episodes of depression.In 1818, Berzelius had a nervous breakdown, said to be due to the stress of his work. The medical advice he received was to travel and take vacation. However, during this time, Berzelius traveled to France to work in the chemical laboratories of Claude Louis Berthollet.
In 1835, at the age of 56, he married Elizabeth Poppius, the 24-year-old daughter of a Swedish cabinet minister.
At 63 he was elected to Honorary membership of the Manchester Literary and Philosophical Society on 18 April 1843
He died on 7 August 1848 at his home in Stockholm, where he had lived since 1806. He is buried in the Solna Cemetery.
Achievements
Law of definite proportions
Soon after arriving in Stockholm, Berzelius wrote a chemistry textbook for his medical students, Lärbok i Kemien, which was his first significant scientific publication. He had conducted experimentation, in preparation for writing this textbook, on the compositions of inorganic compounds, which was his earliest work on definite proportions. In 1813–4, he submitted a lengthy essay on the proportions of elements in compounds. The essay commenced with a general description, introduced his new symbolism, and examined all the known elements. The essay ended with a table of the "specific weights" of the elements, where oxygen was set to 100, and a selection of compounds written in his new formalism. This work provided evidence in favour of the atomic theory proposed by John Dalton: that inorganic chemical compounds are composed of atoms of different elements combined in whole number amounts. In discovering that atomic weights are not integer multiples of the atomic weight of hydrogen, Berzelius also disproved Prout's hypothesis that elements are built up from atoms of hydrogen. Berzelius's last revised version of his atomic weight tables was first published in a German translation of his Textbook of Chemistry in 1826.Chemical notation
In order to aid his experiments, he developed a system of chemical notation in which the elements composing any particular chemical compound were given simple written labels—such as O for oxygen, or Fe for iron—with their proportions in the chemical compound denoted by numbers. Berzelius thus invented the system of chemical notation still used today, the main difference being that instead of the subscript numbers used today, Berzelius used superscripts.Discovery of elements
Berzelius is credited with discovering the chemical elements cerium and selenium and with being the first to isolate silicon, thorium, titanium and zirconium. Berzelius discovered cerium in 1803and selenium in 1817.
Berzelius also discovered how to isolate silicon in 1824,
and thorium in 1824.
Students working in Berzelius's laboratory also discovered lithium, lanthanum, and vanadium.
Berzelius discovered amorphous silicon by repeating an experiment performed by Gay-Lussac and Thénard in which they reacted silicon tetrafluoride with potassium metal which produced very impure silicon. In a variation of this experiment Berzelius heated potassium fluorosilicate with potassium. It produced potassium silicide which he then stirred with water to produce relatively pure silicon powder. Berzelius recognized this powder as the new element of silicon, which he called silicium, a name proposed earlier by Davy.
Berzelius was the first to isolate zirconium in 1824, but pure zirconium was not produced until 1925, by Anton Eduard van Arkel and Jan Hendrik de Boer.