Theodor Schwann

Theodor Schwann
Theodor Schwann
Born	(1810-12-07)7 December 1810 Neuss, First French Empire (now in Germany)
Died	11 January 1882(1882-01-11) (aged 71) Cologne, German Empire
Known for	Cell theory Schwann cells
Influences	Johannes Peter Müller

Theodor Schwann (7 December 1810 – 11 January 1882) was a German physiologist. His many contributions to biology include the development of cell theory, the discovery of Schwann cells in the peripheral nervous system, the discovery and study of pepsin, the discovery of the organic nature of yeast, and the invention of the term metabolism.

Early life

Schwann was born in Neuss. His father was a goldsmith, later a printer. Schwann studied at the Jesuits College in Cologne, and then at Bonn, where he met physiologist Johannes Peter Müller.^[1]

Contributions

It was during the four years spent under the influence of Müller at Berlin that Schwann's most valuable work was done. Müller was at this time preparing his great book on physiology, and Schwann assisted him in the experimental work required. Schwann observed animal cells under the microscope, noting their different properties. Schwann found particular interest in the nervous and muscular tissues. He discovered the cells which envelope the nerve fibers, now called Schwann cells in his honour.

Schwann discovered the striated muscle in the upper esophagus and initiated research into muscle contraction, since expanded upon greatly by Emil du Bois-Reymond and others. Müller directed Schwann's attention to the process of digestion, and in 1837 Schwann isolated an enzyme essential to digestion, which he called pepsin.^[1]

In his later years, Schwann found growing interest in theological issues. Schwann died in Cologne on 11 January 1882.

Cell theory

In 1838, Matthias Jakob Schleiden found that all plants are composed of cells, and communicated the finding to Schwann, who had found similar structures in the cells of the notochord, as shown earlier by Müller. Other researchers confirmed the similarity, as explained in Schwann's Microscopic Investigations on the Accordance in the Structure and Growth of Plants and Animals, where he concluded, "All living things are composed of cells and cell products".^[2]

This became cell theory or cell doctrine, compatible with Schwann's observations across all other tissues he investigated, concluding a cellular origin even of nails, feathers, and tooth enamel. Schleiden's contribution extended cell doctrine to plants. In 1857, pathologist Rudolf Virchow posed the maxim Omnis cellula e cellula—that every cell arises from another cell—widely accepted. By the 1860s, cell doctrine became the conventional view of the elementary anatomical composition of plants and animals.

Vitalism and germ theory

Schwann was the first of Johannes Peter Müller's pupils to break with vitalism and work towards a physico-chemical explanation of life. Schwann also examined the question of spontaneous generation, which led to its eventual disconfirmation. In the early 1840s, Schwann went beyond others who had noted simply the multiplication of yeast during alcoholic fermentation, as Schwann assigned the yeast the role of primary causal factor, and then went further and claimed it was alive. Embattled controversy ensued as eminent chemists alleged that Schwann was undoing scientific progress by reverting to vitalism.^{[citation needed]}

After publishing anonymous mockery in a journal of their own editorship, they published a purely physicochemical if also hypothetical explanation of the interaction resulting in fermentation. As both the rival perspectives were hypothetical, and there was not even an empirical definition of 'life' to hold as a reference frame, the controversy—as well as interest itself—fell into obscurity unresolved. Pasteur began fermentation researches in 1857 by approximately just repeating and confirming Schwann's, yet Pasteur accepted that yeast were alive, thus dissolving the controversy over their living status, and then Pasteur took fermentation researches further.^{[citation needed]}

In retrospect, the germ theory of Pasteur, as well as its antiseptic applications by Lister, can be traced to Schwann's influence.^[1]

References

 This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Schwann, Theodor". Encyclopædia Britannica (11th ed.). Cambridge University Press 

Further reading

• Aszmann, O. C. (2000). "The life and work of Theodore Schwann". Journal of reconstructive microsurgery 16 (4): 291–5. doi:10.1055/s-2000-7336. PMID 10871087. 
• Florkin, M. (1958). "Episodes in medicine of the people from Liège: Schwann & the stigmatized". Revue médicale de Liège 13 (18): 627–38. PMID 13591909. 
• Florkin, M. (1957). "1838; Year of crisis in the life of Théodore Schwann". Revue médicale de Liège 12 (18): 503–10. PMID 13466730. 
• Florkin, M. (1957). "Discovery of pepsin by Theodor Schwann". Revue médicale de Liège 12 (5): 139–44. PMID 13432398. 
• Florkin, M. (1951). "Schwann as medical student". Revue médicale de Liège 6 (22): 771–7. 
• Florkin, M. (October 1951). "Schwann at the Tricoronatum". Revue médicale de Liège 6 (20): 696–703. PMID 14883601. 
• Florkin, M. (1951). "The family and childhood of Schwann". Revue médicale de Liège 6 (9). PMID 14845235. 

• Haas, L. F. (1999). "Neurological stamp. Theodore Schwann (1810–82)". J. Neurol. Neurosurg. Psychiatr. 66 (1): 103. PMC 1736145. PMID 9886465. 
• Hayashi, M. (1992). "Theodor Schwann and reductionism". Kagakushi kenkyu. Journal of the history of science, Japan 31 (184): 209–14. PMID 11639601. 
• Kiszely, G. (1983). "Theodor Schwann". Orvosi hetilap (Hungary) 124 (16): 959–62. PMID 6343953. 
• Kosinski, C. M. (2004). "Theodor Schwann". Der Nervenarzt (Germany) 75 (12): 1248–1248. doi:10.1007/s00115-004-1805-5. PMID 15368056. 
• Kruta, V. (1987). "The idea of the primary unity of elements in the microscopic structure of animals and plants. J. E. Purkynĕ and Th. Schwann". Folia mendeliana (Czech Republic) 22: 35–50. PMID 11621603. 

• Lukács, D. (April 1982). "Centenary of the death of Theodor Schwann". Orvosi hetilap 123 (14): 864–6. PMID 7043357. 
• Watermann, R. (1973). "Theodor Schwann accepted the honorable appointment abroad". Medizinische Monatsschrift (Germany, West) 27 (1): 28–31. PMID 4576700. 
• Watermann, R. (1960). "Theodor Schwann as a maker of lifesaving apparatus". Die Medizinische Welt 50: 2682–7. PMID 13783359. 

External links

Wikimedia Commons has media related to Theodor Schwann.

• Short biography and bibliography in the Virtual Laboratory of the Max Planck Institute for the History of Science
• Schwann, Theodor and Schleyden, M. J. 1847. Microscopical researches into the accordance in the structure and growth of animals and plants. London: Printed for the Sydenham Society
•  "Theodor Schwann". Catholic Encyclopedia. New York: Robert Appleton Company. 1913.