Theodor Schwann

Theodor Schwann was a very simple man who stayed away from scientific controversies and petty rivalries that are common in the scientific fraternity. He was much loved and respected by his students. He never married.

He died on 11 January 1882, in Cologne, Germany, at the age of 71.

Theodor Schwann was born on 7 December 1810, at Neuss near Düsseldorf, as the fourth son of Elisabeth Rottels and her husband Leonard Schwann. His father was a goldsmith who later became a printer.

He first went to the Jesuits College in Cologne, and then to Bonn in 1829 where he met the prominent physiologist Johannes Peter Muller. He then proceeded to the University of Würzburg for his medical studies and continued his training at the University of Berlin from where he graduated with a medical degree in 1834. His doctoral dissertation was regarding the respiration of the chick embryo.

At Berlin, Theodor Schwann once again came in contact with Muller who convinced the young man to venture into research. Muller was at that time working on a major book on physiology and Schwann helped him in his research for the project.

He experimented by observing animal cells under the microscope and was particularly fascinated by the nervous and muscular tissues. Over the course of his investigations he came across the cells which envelope the nerve fibers, now called Schwann cells in his honor.

He made extracts from the stomach lining of animals, and discovered that a factor other than hydrochloric acid was instrumental in digestion. Following further research in the area, he successfully isolated the active principle—which he named pepsin—in 1836.

During the 1830s, he performed a series of experiments to determine if the concept of spontaneous generation was true or false. He exposed sterilized broth only to heated air in a glass tube and observed that no micro-organisms were detectable. This convinced him that the idea of spontaneous generation was false.

Around this period, he identified the role that micro-organisms played in alcohol fermentation and putrefaction. Following intensive experimentation he theorized that yeast originated the chemical process of fermentation. However, it was not until over a decade later that his explanation of fermentation was accepted by other scientists.

He discovered the Schwann cells, a variety of glial cell that keep peripheral nerve fibers (both myelinated and unmyelinated) alive. The cells are involved in many important aspects of peripheral nerve biology.

Schwann along with Matthias Schleiden is credited to have given the cell theory which describes the properties of cells. His theory that along with plants, animals are also composed of cells or the product of cells in their structures was a major advancement in the field of biology since little was known about animal structure up to the mid-19th century.