Contributed by David Rabinovitch, MD (Cand)
Jan (Johannes) Evangelista Purkinje, one of the most prominent Czech scientists of the 19th century, was born in Libochovice Castle on December 17, 1787, in what was then Czech territory under the Austro-Hungarian empire. Purkinje was the first-born son of his parents, Josef and Rosalie Purkinje. Purkinje’s two younger siblings followed: Emanuel (1789–1791) and Josef Jindrich (1793–1833). Jan’s father died abruptly at the age of 47 when Purkinje was just 6 years old.
By the time Purkinje was attending primary school, he had already impressed his teachers with his brilliance, but it was his voice that astonished the local church. The church later sent Purkinje from one Catholic (Piarist) school to another, studying tuition-free in return for singing in the monastery choir. In 1807, after three years of learning under the order of the Piarist Fathers, Purkinje, instead of taking his vows to this monastic group, chose to leave the order and dedicate himself to a scientific career. Prior to Purkinje’s medical education, he completed three years of philosophical study at Charles University in Prague but was unable to continue his studies there due to financial difficulties. He returned home to Libochovice where he supported himself by tutoring various wealthy families before returning once more to Prague to enter the faculty of medicine in 1813. Prominent among his medical professors was ophthalmologist Josef Rottenberg, who was surely a significant influence in Purkinje’s achievements in ophthalmology and later contributed to Purkinje’s doctoral dissertation on vision.
At the conclusion of his medical studies, Purkinje had almost abandoned his hope of a career in academia as it was difficult at this time for native Czechs to attain a professorship. It was his doctoral dissertation, “Contribution to the Understanding of Vision from the Subjective Point of View (1819),” where he determined, through self-examination, that visual sensations are linked to brain activity and the brain's connection to the eye, and therefore may not be activated by external stimuli. This work quickly gained popularity in the realm of physiology and his candidacy for the professorship of Physiology and Pathology at the University of Wroclaw was endorsed by renowned scientists and professors Wolfgang Goethe and Karl Asmund Rudolphi. Purkinje attained a professorship in 1823.
At this point and in rapid succession, Purkinje began his seemingly impossible pursuit to advance all branches of life; in science, expression of his wisdom was found throughout his works in forensic science, pharmacology, histology, and physiology. Purkinje commenced his investigative work in physiological optics, studying various subjective and objective visual phenomena. The history of his work bares resemblance to other well-known tales of near or incomplete discoveries that were later rediscovered by others, in which credit is often given primarily to the latter work.
In 1823, Purkinje defended his habilitation thesis “Contributions to Physiological Research of Sight and Skin System,” which discusses accommodation of the eye, the effects of light intensity and color, the eye's ability to track moving objects, direct and indirect vision, and the optic nerve’s location in the retina. This work was the first to describe the principle of ophthalmoscopy.[6,10,11] Using a concave spherical lens and a candle, Purkinje was able to illuminate and observe internal ophthalmic structures with great clarity; in moments he could examine the fundus, optic nerve head, and vessels of the posterior poles in un-dilated eyes. For decades this work was overlooked or forgotten, until 27 years later when the classic description of the ophthalmoscope was published by Herman Vonn Helmholtz. In the nearly 3 decades between Purkinje and Helmholtz, several attempts were made to investigate the principles underlying ophthalmoscopy, unfortunately with little mention of Purkinje.[5,6]
Purkinje images came to fruition following his proposition for a novel method of continuous objective investigation of the eye. Purkinje highlighted the use of reflective images to measure the curvature of the cornea, providing the basis for keratometry and ophthalmometry.[6,11] Once again, in 1837, after years of Purkinje’s work going unnoticed, Sanson described the reflection in detail, leading to the evolution of the Purkinje-Sanson images. Purkinje’s success in ophthalmic discovery continued, and the Purkinje effect (or Purkinje shift) was born soon after. The Purkinje effect describes the phenomenon where color perception is brighter at blue light (short wavelength) than red light (longer wavelength). In essence, it is the shift of the eye’s sensitivity during dark adaptation. Purkinje is also known for his drawings of the tree of the eye, the Purkinje Tree. Through self-experiment, Purkinje also characterized the effects of Digitalis and belladonna on vision.
In 1827, Purkinje celebrated his 40th birthday and married Rudolphi's 27-year-old daughter, Julia Agnes. They had two daughters and two sons. His sons, Emanuel (1831–1882) and Karel (1834–1868), survived into adulthood. Unfortunately, his daughters Rosalie and Johanka died during a cholera epidemic. His wife died of typhoid three years later, and Purkinje never remarried.
After a period of grief, Purkinje refocused his attention on his work, greatly expanding his research outside of ophthalmology and making some of his most significant discoveries. However, with so many different scientific endeavors happening alongside each other, his requests for funding and instruments for new projects were often denied. For instance, it took 9 years for his request for a new microscope to be accepted. Nonetheless, these 9 years were worth the wait, as this new microscope allowed for microscopic examination of animal tissues, leading to the discovery of Purkinje cells (large branching neurons located in the middle cerebellar layer, 1837) and Purkinje fibers (fibrous tissue which conducts electrical impulses from the atrioventricular node to all parts of the hearts ventricles, 1839).[1,9]
Jan Purkinje died in Prague on July 27, 1869, leaving behind his extraordinary scientific legacy. Streets in his name, commemorative plaques, monuments, permanent exhibits dedicated to his life, and even Universities have been established across Europe to pay tribute to the Purkinje. Purkinje’s fame, which includes the immortalization of his name in cardiology across the world, was not born in one day, nor was it made from achievements in one field. His thoughts, ideas, and his name have become the mainstay in science curriculums across the world, and his achievements have remained significant contributions. Finally, his legacy persists through The University of Jan Evangelista Purkyne (UJEP), and Živa, the magazine for the popularization of biology.