St. Thomas School, Hillerstraße 7, 04109 Leipzig, Germany
Engelmann was very musical and graduated from the St. Thomas School in Leipzig.
College/University
Gallery of Theodor Engelmann
University of Jena, Fürstengraben 1, 07743 Jena, Germany
In the winter semester of 1861-1862 Engelmann began his studies in the natural sciences and medicine at Jena, where he was introduced to comparative anatomy by Gegenbaur, to physiology by his brother-in-law, Adalbert von Bezold, and to botany by Schleiden.
Gallery of Theodor Engelmann
University of Heidelberg, Grabengasse 1, 69117 Heidelberg, Germany
Engelmann studied at Heidelberg.
Gallery of Theodor Engelmann
University of Leipzig, Augustusplatz 10, 04109 Leipzig, Germany
In Leipzig Engelmann finished his studies and in 1867 took his doctorate under the ophthalmologist Theodor Ruete, with a dissertation on the cornea.
Gallery of Theodor Engelmann
University of Gottingen, Wilhelmsplatz 1, 37073 Göttingen, Germany
Engelmann studied at Gottingen.
Career
Achievements
Membership
Royal Prussian Academy of Sciences
Engelmann was a member of the Royal Prussian Academy of Sciences.
German Academy of Sciences Leopoldina
Engelmann was a member of the German Academy of Sciences Leopoldina.
Austrian Academy of Sciences
Engelmann was a member of the Austrian Academy of Sciences.
Göttingen Academy of Sciences
Engelmann was a member of the Göttingen Academy of Sciences.
Finnish Academy of Science and Letters
Engelmann was a member of the Finnish Academy of Science and Letters.
Accademia dei Lincei
Engelmann was a member of the Lincean Academy.
Royal Academy of Science, Letters and Fine Arts of Belgium
Engelmann was a member of the Royal Academy of Science, Letters and Fine Arts of Belgium.
Academy of Sciences of Turin
Engelmann was a member of the Academy of Sciences of Turin.
Royal Netherlands Academy of Arts and Sciences
Engelmann was a member of the Royal Netherlands Academy of Arts and Sciences.
University of Jena, Fürstengraben 1, 07743 Jena, Germany
In the winter semester of 1861-1862 Engelmann began his studies in the natural sciences and medicine at Jena, where he was introduced to comparative anatomy by Gegenbaur, to physiology by his brother-in-law, Adalbert von Bezold, and to botany by Schleiden.
Theodor Wilhelm Engelmann was a German botanist, microbiologist, physiologist, and university professor. He is known for his discoveries concerning photosynthesis and also the operation of muscles.
Background
Theodor Wilhelm Engelmann was born on November 14, 1843, in Leipzig, Germany. He was the son of the well-known bibliographer and publisher Wilhelm Engelmann and his wife, Christiane Therese Hasse, the daughter of the Leipzig historian Friedrich Christian August Hasse.
Education
Engelmann was very musical and graduated from the St. Thomas School in Leipzig. He also was a passionate botanist and microscopist while still a schoolboy. In the winter semester of 1861-1862 he began his studies in the natural sciences and medicine at Jena, where he was introduced to comparative anatomy by Gegenbaur, to physiology by his brother-in-law, Albert von Bezold, and to botany by Schleiden. He continued his studies at Heidelberg and Gottingen, but it was at Leipzig that he finished his studies and in 1867 took his doctorate under the ophthalmologist Theodor Ruete, with a dissertation on the cornea.
At the beginning of 1867 Engelmann went to Utrecht, at Ruete’s recommendation, as an assistant to the physiologist and ophthalmologist Franz Cornelis Donders. He became an associate professor of general biology and histology at Utrecht in 1871. In 1877 he served as rector. In 1888 he was Donders’ successor in the chair of physiology, having declined offers of appointment from Freiburg im Breisgau, Zurich, and Jena, primarily because he suffered greatly from migraine headaches.
In the winter semester of 1897 Engelmann became a professor of physiology at Berlin, succeeding Emil du Bois-Reymond. He not unhesitatingly exchanged his contemplative existence at Utrecht for the activity of the cosmopolitan city of Berlin. Senile diabetes and failing strength forced him to retire on October 14, 1908. He died the following year from progressive arteriosclerosis.
Before his dissertation, he had already published eight papers in zoology and biology, especially on Infusoria, the connection between the nerves and the muscle fibers, and the excitability of nerves and muscles under the influence of induction currents. The microscope was also his most important research tool in Utrecht. At the same time, Engelmann studied on the transmission of stimuli in the muscles of the ureter and on the physiology of peristalsis. He also perfected the method of lever suspension with the frog heart and analyzed the laws of extrasystoles, the refractory phase, and the compensatory pause (1892-1895). Earlier he had determined the velocity of the conduction of stimuli in cardiac muscle (1875).
Engelmann’s second main area of work was the physiology of muscle contraction, in which he made much use of the microscope. He described the diminution of double refraction in the contracted muscle fiber in polarized light (1873) and believed the cause of contraction to be a shifting of fluid from the isotropic to the anisotropic substance, suspecting swelling processes to be the cause. He constructed an artificial model of the muscle fiber (a birefringent violin string) in order to elucidate the contraction process and believed that he was able to demonstrate that heat was directly transformed into mechanical work in the course of contraction (1893). A lively conflict of scientific opinion arose from this, a battle he finally lost.
A remarkable investigation with Genderen furnished the microscopic proof that the retinal cones of the frog shift in the course of the change from light to darkness (1884) and that such movements are binocular even if only one of the two eyes is illuminated. Finally, Engelmann analyzed the sensitivity of protozoa to light and color and chemotaxis in bacteria.
Engelmann’s interests were directed very early to microscopy and cellular physiology. At first, therefore, his subjects were more biological than physiological. Only with cardiac physiology did he enter the central area of experimental animal physiology. Engelmann never expressed himself on questions of theoretical biology or natural philosophy.
Engelmann was an energetic advocate of myogenic formation and conduction of stimuli. He claimed the same thing for the heart and proved his claim with the famous “zig-zag experiment,” in which the heart of a frog was dissected spirally. In spite of its nerves being cut, the strip remained capable of forming and conducting stimuli.
He had a difference of opinion with Ranvier concerning the structure of the axis cylinder of peripheral nerves since Engelmann had incorrectly believed that the nodes of Ranvier represented a discontinuity of the axis cylinder.
Membership
Engelmann was a member of both German and foreign scientific societies.
Royal Prussian Academy of Sciences
,
Germany
German Academy of Sciences Leopoldina
,
Germany
Austrian Academy of Sciences
,
Austria
Göttingen Academy of Sciences
,
Germany
Finnish Academy of Science and Letters
,
Finland
Accademia dei Lincei
,
Italy
Royal Academy of Science, Letters and Fine Arts of Belgium
,
Belgium
Academy of Sciences of Turin
,
Italy
Royal Netherlands Academy of Arts and Sciences
,
Netherlands
Personality
Engelmann lived a simple, modest, and retiring life. He loved music and musicians. His house in Utrecht and later in Berlin was frequently a meeting place for well-known musicians. He was an avid cellist and a close friend of Johannes Brahms, who dedicated the Quartet in B Major op. 67 to him.
Interests
music
Connections
In 1869 Engelmann married Donders’ daughter, Marie. Following her early death he married Emma Vick, a well-known pianist whose professional name was Emma Brandes.