Johannes Peter Müller

In April 1827, Müller married the gifted musician Nanny Zeiller.

He was fatigued from his full time teaching profession, wide-ranging researches, and the publication of books. In 1827, 1840, and 1848, he suffered bouts of depression that left him incapable of working for several months.

He died on 28 April 1858, in Berlin, at the age of 56. His recurrent depression is often speculated to be the cause of his death.

Johannes Peter Müller was born on 14 July 1801, in Koblenz, Germany, into a poor family. His father was a shoemaker.

Müller’s father wanted him to continue his family trade and was about to apprentice him to a saddler, when a Prussian educational reformer, Johannes Schulze, noticed Müller’s skills in mathematics and classical languages and persuaded Müller’s father to send him to the Bonn University.

In 1819, he enrolled in the Bonn University to study medicine. Three years later in 1822, he received his medical degree with a doctoral thesis on animal movement patterns, especially in insects.

He next studied at the Berlin University where he was encouraged to discard those systems of physiology which were not based on a careful study of nature. The Berlin anatomist Carl Asmund Rudolphi inspired him to take up microscopic studies.

Soon, he became an expert microscopist. In 1824, after he had passed the Prussian state medical examination and returned to Bonn, he received the Frauenhofer microscope from Rudolphi to carry out his future researches.

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 lecture he defined his scientific strategy of merging careful observation of natural forms with limited philosophical theorization.

Through his years of research at Bonn he provided information in various segments of physiology, especially the voice, speech, hearing, visual, circulatory, endocrine, and reproductive systems. He also elucidated the chemical and physical properties of lymph and blood.

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 described human binocular vision and the structure of insect eyes.

In 1826, he also published ‘Ueber die phantastischen Gesichtserscheinungen’ (On Fantasy Images), which was a study of optical illusions. His work showed that the visual system is active recorder of external events.

Through his studies of the nervous system, he elucidated that nerves are not merely passive conductors of outer stimuli. In ‘Handbuch der Physiologie des Menschen’ (Elements of Physiology), he explained that each nerve responds to stimuli only in a specific way.

Müller’s most important discovery was his finding that each of the sensory organs responds to different kinds of stimuli in their own unique way. His research on vision elucidated that the eye as a sensory organ not only responds to external optical stimuli but also internal stimuli triggered by the imagination.

He studied the journey of impulses from afferent nerves to efferent nerves, further explaining the concept of reflex action. He thus confirmed the law named after Charles Bell and François Magendie.

His publication ‘Über den feineren Bau und die Formen der krankhaften Geschwülste’ (On the Nature and Structural Characteristics of Cancer and of Those Morbid Growths Which May Be Confounded with It) established pathological histology as an autonomous branch of science.

A bronze statue by Joseph Uphues was erected at Koblenz in 1899, in Müller’s memory.