Johannes Peter Müller

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Koblenz, Germany
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Koblenz, Germany

Johannes Peter Müller was a German physiologist and comparative anatomist who was thought to be the most important natural philosopher of the 1800s. He was best known for his two-volume book “Handbuch der Physiologie des Menschen für Vorlesungen” (Elemente der Physiologie, 1834–40), which became the most important textbook in the field of medicine. When he was born, his father, who made shoes, planned to teach him how to work with leather. But one of his teachers saw how good he was at math and classical languages and convinced his father to send him to Bonn University. By that time, Müller was interested in medicine and the natural sciences. He went to Bonn to study medicine and got a degree in medicine three years later. He went on to study at Berlin University, where he met the famous anatomist Rudolphi, who encouraged him to study microscopic things. In 1824, he became a Lecturer in physiology and comparative anatomy at the University of Bonn. Two years later, he was made an Associate Professor, and in 1830, he was made a full Professor. Then, he was given the prestigious job of Medical Professor at Berlin University, where he stayed for 25 years. He was a great teacher, and Rudolf Virchow, a cellular pathologist, and Hermann Helmholtz, a physiologist and physicist, were two of his most famous students. As a researcher, his deep knowledge of the subject matter caught the attention of other scholars. In his personal life, he had many bouts of depression that made it hard for him to work.

Early years and childhood

On July 14, 1801, Johannes Peter Müller was born into a poor family in Koblenz, Germany. His father used to make shoes.

Müller’s father wanted him to take over the family business and was about to send him to work as an apprentice for a saddler when Johannes Schulze, a Prussian educational reformer, saw how good Müller was at math and classical languages and convinced Müller’s father to send him to Bonn University.

He went to Bonn University to study medicine in 1819. In 1822, he got his medical degree by writing a doctoral thesis about how animals move, especially insects.

He then went to Berlin University to study, where he was told to get rid of systems of physiology that did not come from a careful study of nature. Carl Asmund Rudolphi, an anatomist in Berlin, encouraged him to study things up close.

He soon learned how to use a microscope well. After he passed the Prussian state medical exam and went back to Bonn in 1824, Rudolphi gave him the Frauenhofer microscope to help him with his research.

Johannes Peter Müller’s Career

Meanwhile, in October 1824, he delivered a lecture ‘Uber das Bedürfnis der Physiologie nach einer philosophischen Naturbetrachtung’ (On the Need of Physiology for a Philosophical Contemplation of Nature). In the talk, he talked about how his scientific method combines careful observation of natural forms with only a small amount of philosophical theory.

During his years of research at Bonn, he found out a lot about the voice, speech, hearing, visual, circulatory, endocrine, and reproductive systems, among other things. He also explained what lymph and blood are made of and how they work.

In 1826, he published ‘Zur vergleichenden Physiologie des Gesichtssinnes des Menschen und der Thiere’ (On the Comparative Physiology of Vision in Men and Animals). It talked about how people see with two eyes and how insect eyes are made.

He also wrote a book about optical illusions called “Ueber die phantastischen Gesichtserscheinungen,” which came out in 1826. His work showed that the visual system keeps track of what is going on outside.

Through his studies of the nervous system, he showed that nerves are not just passive pathways for stimuli from the outside world. In “Handbuch der Physiologie des Menschen” (Elements of Physiology), he wrote that each nerve can only respond to a stimulus in a certain way.

He compared the endocrine and reproductive systems in great detail. In 1830, he published his findings in a book called “De glandularum secernetium and Bildungsgeschichte der Genitalien.” He said that the secretions that control how the body works come from glands, not blood vessels. He also found the blood vessels that cause a man to get an erection.

He did experiments to prove that the dorsal roots of spinal nerves carry sensory fibers and the ventral roots carry motor fibers. This was a theory by doctor Charles Bell and physiologist Francois Magendie.

Rudolphi died in 1832, and Müller said that he wanted to get the prestigious job of Berlin professorship. He finally got the job in 1833 and stayed there until 1858. He worked hard to make Berlin a place where people could compare and study bodies.

He taught physiology, human anatomy, sensory anatomy, comparative anatomy, and pathological anatomy as a professor of medicine at Berlin. He also helped run the dissection lab for medical students and looked over Prussian candidates for medical degrees.

In Berlin, one of his main goals was to fix up the university’s anatomical museum. He was very interested in gathering all the known animal forms in order to figure out how life worked.
Between 1833 and 1844, he used his vast knowledge of physiology to write the important book “Handbuch der Physiologie.” For much of the 19th century, it was the most important book in the field.

Meanwhile in 1834, he established the ‘Archiv für Anatomie, Physiologie und wissenschaftliche Medicin’. The prestigious journal had annual reports on the progress being made in physiology and anatomy research all over Europe. In 1834, he was also chosen to join the Royal Swedish Academy of Sciences as a foreign member.

After his assistant Theodor Schwann showed that the cell is the basic unit of an animal’s body, Müller used a microscope to look at the cellular structure of tumors. His observations were published in ‘Ueber den feineren Bau der krankhaften Geschwülste’ (On the Fine Structure of Pathological Tumours) in 1838.

In the late 1830s, he also made a distinction between marine organisms and came up with a new way to group the myxinoids (hagfishes) and plagiostomes (cartilaginous fishes like sharks) into groups.
In the 1840s, he kept studying sea creatures like cyclostomes (lampreys) and ganoid (scaly) fishes. He did a lot of research on the echinoderms, which are animals like starfish that have radial symmetry.

In addition to teaching and doing research, he had a lot of administrative work to do. He was Dean of the Medical Faculty from 1835 to 1836 and from 1843 to 1844. From 1838 to 1839 and from 1847 to 1848, he was Rector of the Berlin University.

Throughout his career, he often went through very sad times. After a scary shipwreck in 1855, in which one of his young students drowned, he felt hopeless for the last time. He felt responsible for the student’s death and never got over feeling guilty about it.

After this happened, he still taught and did research, but his health started to get worse. He became more and more dependent on opium to ease his stomach pain and help him sleep.

During his life, he taught many famous scientists and physiologists, such as Hermann von Helmholtz, Emil du Bois-Reymond, Theodor Schwann, Friedrich Gustav Jakob Henle, Carl Ludwig, Ernst Haeckel, etc.

Works of note

Müller’s most important discovery was that each sensory organ responds to different kinds of stimuli in its own unique way. His research on vision showed that the eye, which is a sense organ, responds not only to light from the outside but also to images in the mind.

He looked at how impulses move from afferent nerves to efferent nerves, which helped him explain the idea of reflex action in more detail. So, the law named after Charles Bell and Francois Magendie was made official.

His book “Über den feineren Aufbau und die Formen der krankhaften Geschwülste” (On the Nature and Structural Characteristics of Cancer and of Those Morbid Growths That Can Be Mistaken for It) made pathological histology a separate branch of science.
In 1899, a bronze statue by Joseph Uphues was put up in Koblenz to honor Müller.

Personal History and Legacies

In April 1827, Müller married Nanny Zeiller, a talented musician.
He was tired from teaching full time, doing research on a wide range of topics, and writing books. In 1827, 1840, and 1848, he was depressed for long periods of time which kept him from working.

He died in Berlin on April 28, 1858, when he was 56 years old. People often think that his death was caused by his depression.

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He wanted to be a priest at first. But over time, he became more interested in the natural world and turned to medicine.