Christian Schönbein

January 18, 1799 (age 69)

Metzingen, Germany

In 1820 Schönbein accepted a post in the chemical factory of J. N. Adam in Hemhofen, near Erlangen. He remained friends with Schelling until the latter’s death in 1854. In 1828 Schönbein moved to Basel. In 1852, when the professorship was divided, Schönbein retained the chair of chemistry. Schönbein’s speculative bent is evident even in his early studies (from 1835 on) on the passivity of iron. He started from the well-known fact that iron reacts with dilute nitric acid but not with concentrated nitric acid. He sought to explain this phenomenon as a type of polymerism (he himself spoke always of isomerism) and thus disagreed with Faraday’s explanation of a layer of oxide on the iron. Schönbein assumed that a conversion of the metallic iron takes place. But under certain conditions the poles that attract oxygen are directed to the inside of the metallic iron while those that repel oxygen are directed to the outside, thus producing passive iron. He claimed that too little is known about the nature of matter and the workable forces in it to give definitive answers to these questions. Schönbein’s reasoning was based on the analogies he drew from his 1835 lecture on isomerism, in which he stated that all known examples of isomerism (for example, tartaric and racemic acids, fulminic and cyanic acids) are dimorphic, with the exception of sulfur. He concluded that all dimorphic substances must be composite, and that sulfur is a compound. Schönbein is known primarily for his work on ozone. While conducting experiments on the decomposition of water (autumn 1839), he noticed that the oxygen obtained in the process had a peculiar odor similar to that produced when a large electrical machine is operating—a similarity first noted by the Dutch chemist van Marum (1785). He also discovered that it bleaches litmus, frees iodine from potassium iodide, and changes potassium ferrocyanide into ferricyanide. Schönbein’s ideas concerning the nature of ozone were rather confused. At first, he thought that nitrogen is composed of ozone and hydrogen. But phosphorus cannot decompose nitrogen (“ozone-hydrogen”) unless another substance is present that can combine with the hydrogen. That substance is oxygen. Thus nitrogen is decomposed by phosphorus only in the presence of oxygen. The hydrogen in the nitrogen reacts with the oxygen of the water and ozone partly liberates and partly is bound with the phosphorus to “ozone-phosphorus. ” Like phosphorus trichloride, “ozone-phosphorus”is decomposed by water, namely into phosphorous acid and nitrogen. Schönbein saw a strong analogy between ozone and the halogens chlorine and bromine. Because the electrical, chemical, and physiological reactions of ozone closely resemble those of chlorine and bromine, he concluded that ozone also forms a salt and that its chemical affinity must place it directly after chlorine. In 1845 Marignac and Auguste Arthur de la Rive proved independently that ozone is formed by an electric spark in pure, dry oxygen. They regarded ozone as oxygen in a particular state of chemical affinity. Although Schönbein persisted in his belief that ozone is a compound, he held that its oxidation state is higher than that of hydrogen, or even more likely, that it is a particular compound of water and oxygen. Similarly, Schönbein concluded that chlorine is a compound. From various reactions, he concluded that ordinary oxygen is converted into ozone and antozone. Oxidation of phosphorus yields ozone; oxidation of metals in the presence of water yields antozone. Schönbein also studied induced reactions. To investigate this phenomenon he first used compounds of sodium sulfite and sodium arsenite; only the former is oxidized when exposed to air. But both sulfite and arsenite are oxidized when mixed and exposed to air. Thus he stated (1858) that the oxidation of sulfite “induces” that of arsenite. From 1836 on, Schönbein’s publications on voltaic current attributed the origin of this form of electricity to chemical action. His 1838 tendency theory stated that the tendency of two substances to combine with each other is sufficient to disturb their chemical equilibrium and to produce an electric current. At the 11 March 1846 meeting of the Naturforschende Gesellschaft in Basel, Schönbein announced his discovery of guncotton. Schönbein produced guncotton by dipping cotton-wool in a mixture of fuming nitric and sulfuric acids and then washing and drying the product. His method of preparation remained a secret until it was discovered independently in 1846 by Böttger and Friedrich Julius Otto. The height of ascent under standardized conditions and the time required for the ascent were recognized as characteristics of each individual substance present in the mixture under investigation. His dynamical ideas are also emphasized. Schönbein was opposed to the atomic theory: he rejected the explanation of chemical combination as the basis for the formation of chemical substances. He thought that the qualitative changes in the formation of chemical substances indicated that every particle of a chemical element is a system of continuously working molecular forces. Schönbein sent a copy of his Beiträge to Faraday; and in a covering letter he pointed out that for years he had doubted the validity of the atomic theory and that he considered the molecule of a compound to be the “centre of physical forces. ” Although Schelling’s influence is clearly evident in the work of Schönbein, he was not strictly a Naturphilosoph. More than once he expressed himself against the views of Schelling and Oken and he passionately denounced Hegel and his school. Nevertheless, Schönbein’s work is filled with speculative remarks lacking an adequate experimental basis and with excessive recourse to analogy.

General
Education
Career
Works
Life Stance
Personality
Connections
References
Album

People Also Searched For

Christian Friedrich Schönbein

chemist professor

Background

Christian Friedrich Schönbein was born on October 18, 1799 in Metzingen, Germany

Education

Around the age of 13 Schönbein was apprenticed to a chemical and pharmaceutical firm at Böblingen. Through his own efforts, he acquired sufficient scientific skills and knowledge to ask for, and receive, an examination by the professor of chemistry at Tübingen. Schönbein passed the exam and, after a series of moves and university studies, eventually acquired a position at the University of Basel in 1828, becoming a full professor in 1835.

Career

In 1820 Schönbein accepted a post in the chemical factory of J. N. Adam in Hemhofen, near Erlangen.

He remained friends with Schelling until the latter’s death in 1854.

In 1828 Schönbein moved to Basel.

In 1852, when the professorship was divided, Schönbein retained the chair of chemistry.

Schönbein’s speculative bent is evident even in his early studies (from 1835 on) on the passivity of iron.

He started from the well-known fact that iron reacts with dilute nitric acid but not with concentrated nitric acid.

He sought to explain this phenomenon as a type of polymerism (he himself spoke always of isomerism) and thus disagreed with Faraday’s explanation of a layer of oxide on the iron.

Schönbein assumed that a conversion of the metallic iron takes place.

But under certain conditions the poles that attract oxygen are directed to the inside of the metallic iron while those that repel oxygen are directed to the outside, thus producing passive iron.

He claimed that too little is known about the nature of matter and the workable forces in it to give definitive answers to these questions.

Schönbein’s reasoning was based on the analogies he drew from his 1835 lecture on isomerism, in which he stated that all known examples of isomerism (for example, tartaric and racemic acids, fulminic and cyanic acids) are dimorphic, with the exception of sulfur.

He concluded that all dimorphic substances must be composite, and that sulfur is a compound. Schönbein is known primarily for his work on ozone.

While conducting experiments on the decomposition of water (autumn 1839), he noticed that the oxygen obtained in the process had a peculiar odor similar to that produced when a large electrical machine is operating—a similarity first noted by the Dutch chemist van Marum (1785).

He also discovered that it bleaches litmus, frees iodine from potassium iodide, and changes potassium ferrocyanide into ferricyanide. Schönbein’s ideas concerning the nature of ozone were rather confused.

At first, he thought that nitrogen is composed of ozone and hydrogen.

But phosphorus cannot decompose nitrogen (“ozone-hydrogen”) unless another substance is present that can combine with the hydrogen.

That substance is oxygen.

Thus nitrogen is decomposed by phosphorus only in the presence of oxygen.

The hydrogen in the nitrogen reacts with the oxygen of the water and ozone partly liberates and partly is bound with the phosphorus to “ozone-phosphorus. ”

Like phosphorus trichloride, “ozone-phosphorus”is decomposed by water, namely into phosphorous acid and nitrogen.

Schönbein saw a strong analogy between ozone and the halogens chlorine and bromine.

Because the electrical, chemical, and physiological reactions of ozone closely resemble those of chlorine and bromine, he concluded that ozone also forms a salt and that its chemical affinity must place it directly after chlorine. In 1845 Marignac and Auguste Arthur de la Rive proved independently that ozone is formed by an electric spark in pure, dry oxygen.

They regarded ozone as oxygen in a particular state of chemical affinity.

Although Schönbein persisted in his belief that ozone is a compound, he held that its oxidation state is higher than that of hydrogen, or even more likely, that it is a particular compound of water and oxygen.

Similarly, Schönbein concluded that chlorine is a compound.

From various reactions, he concluded that ordinary oxygen is converted into ozone and antozone.

Oxidation of phosphorus yields ozone; oxidation of metals in the presence of water yields antozone.

Schönbein also studied induced reactions.

To investigate this phenomenon he first used compounds of sodium sulfite and sodium arsenite; only the former is oxidized when exposed to air.

But both sulfite and arsenite are oxidized when mixed and exposed to air.

Thus he stated (1858) that the oxidation of sulfite “induces” that of arsenite. From 1836 on, Schönbein’s publications on voltaic current attributed the origin of this form of electricity to chemical action.

His 1838 tendency theory stated that the tendency of two substances to combine with each other is sufficient to disturb their chemical equilibrium and to produce an electric current. At the 11 March 1846 meeting of the Naturforschende Gesellschaft in Basel, Schönbein announced his discovery of guncotton.

Schönbein produced guncotton by dipping cotton-wool in a mixture of fuming nitric and sulfuric acids and then washing and drying the product.

His method of preparation remained a secret until it was discovered independently in 1846 by Böttger and Friedrich Julius Otto.

The height of ascent under standardized conditions and the time required for the ascent were recognized as characteristics of each individual substance present in the mixture under investigation.

His dynamical ideas are also emphasized.

Schönbein was opposed to the atomic theory: he rejected the explanation of chemical combination as the basis for the formation of chemical substances.

He thought that the qualitative changes in the formation of chemical substances indicated that every particle of a chemical element is a system of continuously working molecular forces.

Schönbein sent a copy of his Beiträge to Faraday; and in a covering letter he pointed out that for years he had doubted the validity of the atomic theory and that he considered the molecule of a compound to be the “centre of physical forces. ”

Although Schelling’s influence is clearly evident in the work of Schönbein, he was not strictly a Naturphilosoph.

More than once he expressed himself against the views of Schelling and Oken and he passionately denounced Hegel and his school.

Nevertheless, Schönbein’s work is filled with speculative remarks lacking an adequate experimental basis and with excessive recourse to analogy.

Achievements

Invented the fuel cell in 1838.

Works

C.F. Schoenbein.: Chemical Papers 1852-1862. C.F. Schoenbein.: Chemical Papers 1852-1862.

The letters of Faraday and Schoenbein, 1836-1862 The letters of Faraday and Schoenbein, 1836-1862

C.F. Schoenbein: Chemical Papers 1852-1862 (German Edition) C.F. Schoenbein: Chemical Papers 1852-1862 (German Edition)

Menschen Und Dinge: Mittheilungen Aus Dem Reisetagebuche Eines Naturforschers (German Edition) Menschen Und Dinge: Mittheilungen Aus Dem Reisetagebuche Eines Naturforschers (German Edition)

book
- C.F. Schoenbein: Chemical Papers 1852-1862 (German Edition)
  (This book was originally published prior to 1923, and rep...)
- The letters of Faraday and Schoenbein, 1836-1862
  (The letters of Faraday and Schoenbein, 1836-1862, with no...)
- Menschen Und Dinge: Mittheilungen Aus Dem Reisetagebuche Eines Naturforschers (German Edition)
  (This is a reproduction of a book published before 1923. T...)
- C.F. Schoenbein.: Chemical Papers 1852-1862.
- Ueber einige durch die Haarröhrchenanziehung des Papieres hervogebrachten Trennungswirkungen. Contained in: Verhandlungen der Naturforschenden Gesellschaft in Basel, Dritter theil, Zweiter heft, pp. 249-255, 1861.

Membership

1833: Full member of the Swiss Natural Science Society

1846: Foreign member of the Chemical Society of London

1846: honorary member of the Royal Scottish Society of Arts , Edinburgh

1847: Corresponding member of the Physical Society in Frankfurt am Main

1853: honorary member of the Society of Friends of Nature Research in Berlin

1854: Corresponding member of the Bavarian Academy of Sciences

1855: honorary member of the Pollichia

1855: Corresponding member of the Imperial Royal Geological Realm in Vienna

1856: Corresponding member of the Prussian Academy of Sciences

1858: Member of the German Academy of Naturalists Leopoldina

1858: Corresponding member of the Wetterauische Gesellschaft in Haunau

1859: Election to the foreign member of the Bavarian Academy of Sciences

1860: honorary member of the Silesian Society for Fatherland culture

1861: Corresponding member of the Academy of Sciences at Göttingen

1863: Corresponding member of the Académie des Sciences in Paris

1864: honorary member and master of the German High Penitent in Frankfurt am Main

1864: honorary member of the Royal Society of Edinburgh

Connections

Spouse:: Emilie Benz

Main Photo

Christian Schönbein

School period

College/University

Career

Achievements

Membership

Awards

Other Photos

Connections

Connections

book

C.F. Schoenbein.: Chemical Papers 1852-1862.

The letters of Faraday and Schoenbein, 1836-1862

C.F. Schoenbein: Chemical Papers 1852-1862 (German Edition)

Menschen Und Dinge: Mittheilungen Aus Dem Reisetagebuche Eines Naturforschers (German Edition)

Christian Friedrich Schönbein

Background

Education

Career

Achievements

Works

book

Membership

Connections

References

Born

Died

Resting place

Nationality

Ethnicity

Awards

: Special stamp of Swiss Post on the occasion of its 200th birthday