Henle, Friedrich Gustav Jacob
Henle, Friedrich Gustav Jacob
(b. Fürth, near Nuremberg, Germany. 19 July 1809; d, Göttingen, Germany, 13 May 1885)
A student and the closest co-worker of Johannes Müller, Henle helped prepare the way for cytology through his studies on epithelia; created the first histology based on extensive microscopical investigations; and, through his theory of miasma and contagion, was among the precursors of modern microbiology. His father, Wilhelm Henle, was a merchant; his mother, Helena Sophia Diespeck, was the daughter of a rabbi. The social position of a Jewish family in the small town of Fürth was rather circumscribed, but increasing economic prosperity finally made possible relations with cultured circles. Henle received his first instruction at home from a private tutor; later he attended the Gymnasium at Mainz and Coblenz. His education was directed primarily toward classical and modern languages; he was also a good draftsman and was musically talented. In 1820 he suffered an attack of periostitis; it subsided but often recurred. After the family had converted to the evangelical belief in 1821, Henle for a time thought of becoming a minister. Medicine was not considered until, in Coblenz, he met Johannes Müller socially at a home musicale. Henle began his medical studies in October 1827 at the University of Bonn, where he became a member of the Burschenschaft (students’ association) in the fall of 1829. Soon afterward, disappointed by the unkind behavior of other students, he severed this connection by continuing his studies at the University of Heidelberg in the spring of 1830. A year later he returned to Bonn and passed the examination for the doctorate there in August 1831.
Henle’s continuing interest in anatomical investigations was rewarded by Müller’s inviting him on a trip to Paris, where they met Cuvier and Dutrochet. Henle received the M.D. on 4 April 1832 at Bonn with a dissertation on the pupil membrane and the blood vessels within the eye. In March 1833 he passed the state medical examination in Berlin and immediately became an assistant to Müller, who in April 1833 was named professor of anatomy and physiology at Berlin. In the fall of 1834 Henle became Müller’s prosector at the Anatomical Institute. A first attempt to qualify as lecturer failed for political reasons, since all former members of the Burschenschaft were suspected of being enemies of the state. In July 1835 Henle was arrested for this reason and detained to await trial, but through the intervention of Alexander von Humboldt and others he was released from confinement after four weeks. Meanwhile, he lost his post as prosector and, following a long investigation, was condemned to six years in prison in January 1837, yet within a few weeks he was pardoned and thus could return to his post. In the same year he qualified as lecturer in Berlin.
Beginning in the fall of 1840 Henle was professor of anatomy and physiology at Zurich, where Albert Koelliker was his prosector. From his close friendship with the clinician Karl Pfeufer there emerged the Zeitschrift für rationelle Medicin. In the summer of 1844 Henle became professor of anatomy and physiology at Heidelberg, along with Friedrich Tiedemann; when the latter retired, Henle also took over the direction of the Anatomical Institute. The last post of his academic career was at Göttingen, to which he was called in the late summer of 1852. He was active there for thirty-three years.
Very revealing of the romantic and sentimental young Henle is his first marriage. During his stay in Zurich he met and fell in love with Elise Egloff, who worked as a governess in the house of his friends; he set her up in her own lodgings and later arranged for his sister to educate her and give her social polish. They were married in March 1846. One son and one daughter resulted from this union, which ended barely two years later with his wife’s death from tuberculosis. In August 1849 Henle married Marie Richter, the daughter of a Prussian officer; they had four daughters and one son.
Henle’s health often hindered his activity, since slivers were frequently discharged at the site of the periostitis; he also suffered from neuralgia. He died of renal and spinal sarcoma.
Henle was very sociable. He loved witty conversation, encouraged home musicales and evening gatherings for reading, and was happy to open his house for concerts. His political ideas were liberal and nationalistic, but he was unable to become reconciled to Prussia’s domestic politics.
Henle belonged to many scientific organizations, including the Leopoldine Academy, the Belgian Academy of Medicine (honorary member), the Bavarian Academy of Sciences of Munich (foreign member), the Petersburg Academy (corresponding member), the Swedish Academy (foreign member), the Berlin Academy (corresponding member), the Royal Society (foreign member), the Petersburg Academy of Medicine (honorary member), and the Royal Academy of Sciences (Amsterdam).
Seldom is anyone introduced to scientific work as Henle was. Johannes Müller began to edit the Archiv für Anatomie, Physiologie und wissenschaftliche Medizin in 1834, and it became a clearinghouse for studies oriented toward the natural sciences. Henle assumed the major share of the work of editing it and thus became familiar with current topics of biology. After undertaking comparative anatomical studies on the electric organ of the ray and on annelids, he soon turned his attention to increasingly precise microscopical research. Hints had been accumulating from all sides regarding the smallest structural elements of plant and animal organisms. The concept of the cell first became current among the botanists but was quickly extended to animals as well. Along with Gabriel Valentin, Henle was among the first authors to use the term “cell.” In volume XI of the Encyclopädisches Wörterbuch der medicinischen Wissenschaften (1834) he had written on epidermis and epithelium but gave only a rather general account for both. His elucidations of fibrous cartilage and fatty and fibrous tissue, which appeared in 1835 in volume XII of the work, were also only general. Yet in the same year, in volume XIII (p. 125), he described the components of the gall bladder as cylindrical corpuscles, some of which appear alone and some “like basalt columns joined lengthwise, so that the chopped-off end surfaces lie in a plane. If they are turned upward under the microscope, these surfaces appear more or less angular and like cells.” This description doubtless refers to the highly prismatic epithelium of the gall bladder.
In 1837 Henle presented as his Habilitationsschrift an investigation of the epithelium of the intestinal villi which demonstrated that he was already one of the leading experts in this field of histology. The extent of his progress is also shown by his lecture of 16 February 1838 to the Hufelandsche Medicinisch-Chirurgische Gesellschaft on mucus and pus formation. He consistently called the structural elements of the epithelium “cells”; he also described the epithelium of the urinary bladder as a form intermediate between the cylindrical and the pavement epithelium (p. 6). The dependence of the forms of the cell and of the nucleus on position and pressure in their vicinity is clearly shown (p. 7); on the other hand, Henle’s observations on the origin of pus cells later proved to be false. He reported on the extension of the epithelia in the human body in 1838, distinguishing three types: pavement, cylindrical (columnar), and ciliated. Moreover, he established that they cover all the liquid-free surfaces of the body, all the inner surfaces of its canals and ducts, and all the walls of its cavities.
Henle’s study of the larynx, which was highly praised by Humboldt, was a completely independent comparative anatomical work. In the last period of his activity in Berlin he studied problems in pathology that he had encountered in his editorial work on Müler’s Archiv By far the most important of these was his article “Von den Miasmen und Kontagien,” which foresaw the bacterial nature of many diseases. At this time the term “miasma” was used for causes of disease which acted on the body from the outside, while “contagia” acted on or in the body itself. But sharp boundaries between these two should not exist, since diseases originating from miasma could become contagious. Most important was the knowledge that the carriers of disease were actually living material and that therefore the contagium, like a parasite, colonized the host body. As a result of its own powers of reproduction, even a small group of contagia suffices to cause a specific disease. Such ideas, although not absolutely new, were often considered unworthy of belief; it required more than thirty years for their acceptance.
Müller’s influence on Henle expressed itself principally in the latter’s comparative-anatomical and zoological investigations. With Henle’s move to Zurich this source of inspiration was closed off; he continued his studies, begun in 1839 at Berlin, for his book Allgemeine Anatomie (1841). The first part of the work treated the chemical composition of the human and animal body; it offered nothing original. In contrast, the second part, “Lehre von den Formbestandteilen,” was a major advance on Bichat’s efforts of forty years before. Bichat’s achievements were fully recognized by Henle, who called him the “creator of histology” (p. 122). But now the development of the microscope and the progress in the techniques of investigation offered far better possibilities, as Henle’s historical sketch (pp. 134–149) shows. Yet his arrangement was incomplete: he did not place the connective and supporting substances together, as Reichert did for the first time four years later. Even the different epithelia did not yet form a unified group in Henle’s system. On this he wrote (pp. 132–133): “A rational system of histology must employ the transformations of the cells as a principle of classification, so that groups of tissue can be formed according to whether, for example, the cells remain discrete or join lengthwise in rows, or expand into star shapes, or split into fibers, and so forth.” Since the available information did not permit such a systematic classification, Henle satisfied himself with demonstrating only occasionally the relationship between basic elements.
It is remarkable that, despite his great experience in microscopy, he could not free himself of Schwann’s error concerning cell formation. He believed that the basic material for the formation of new cells consisted of an unformed mass called cytoblastem. He did not know of the divisions within the cell; yet Remak described them in 1841, the year in which Henle’s Allgemeine Anatomie was completed. Henle’s work. derives its particular importance from its constant attention to physiology—and thus to function, nourishment, development, and regeneration of the various tissues. This physiology of tissues was for Henle the foundation of general or rational pathology, “which attempts to understand the processes and symptoms of disease as the lawlike reactions of an organic substance endowed with peculiar and inalienable powers against abnormal external influences” (Allgemeine Anatomie, foreword, p. vii).
An important work of its time was Henle’s Handbuch der rationellen Pathologie. It stems chiefly from his years at Heidelberg and presents pathology, one of the fundamentals of the physician’s activity, again as resting on scientific knowledge; previously medicine—at least in German—speaking areas—was practiced for several decades primarily in the light of Naturphilosophie. of still greater influence was his Handbuch der systematischen Anatomie. Composed in Göttingen over a period of sixteen years, it contains the entire contemporary knowledge of the structure of the human body and a multitude of good illustrations. If the presentation of the central nervous system is disregarded, the work may still be useful for orientation in the subject of gross human anatomy and its occasional variations. It did not become obsolete as a textbook until the functional approach to anatomy gained dominance.
Henle’s name is best known today for the loopshaped portion of the nephron named for him. His observation of it in 1862, supported by isolation preparations, was correct in itself but the interpretation was completely wrong: according to Henle, there were two loop-shaped tubules, each of which was connected at one end to a different renal corpuscle. Nevertheless, his study resulted in a new series of investigations on the kidneys through which, between 1863 to 1865, their structure was definitively determined.
Henle’s most important publications are De membrane pupillari aliisque oculi membranis pellucentibus (Bonn, 1832), his inaugural diss.; Symbolae ad anatomam villorum intestinalium, inprimis eorum epithelii et vasorum lacteorum (Berlin, 1837): “Ueber Schleimund Eiterbildung und ihr Verhältnis zur Oberhaut,” in Hufelands Journal der praktischen Heilkunde, 86, pt. 5 (1838). 3–62: “Ueber die Ausbreitung des Epitheliums im menschlichen Körper,” in Archiv für Anatomie, Physiologie und wissenschaftliche Medizin (1838), pp. 103–128; Vergleiehend-anatomische Beschreibung des Kehlkopfes mit besonderer Berücksichtigung des Kehlkopfes der Reptilien (Leipzig. 1839); Pathologische Untersuchungen (Berlin, 1840), pt. 1 also issued separately by Felix Marchand as Von den Miasmen und Kontagien, no. 3 in Sudhoffs Klassiker der Medizin (Leipzig, 1910) and published in English translation by George Rosen as “On Miasmata and Contagia,” in Bulletin of the Institute of the History of Medicine, 4 (1938), 907–983; Allgemeine Anatomie, vol. VI of S. T. von Soemmering, Vom Bane des menschlichen Körpers (Leipzig, 1841); Handbuch der rationellen Pathologie, 2 vols, in 3 pK (Brunswick, 1846–1853): Hundhuch der systematischen Anatomie des Menschen, 3 vols, in 7 pts. (Brunswick, 1855–1871); and “Zur Anatomie der Niere,” in Abhandlungen der Cesellschaft der Wissenschaften zu Göttingen, 10 (1862). 223–254.
On Henle and his work, see two writings by Friedrich Merkel; Jacob Henle (Brunswick, 1891), a detailed biography with an evaluation of Henle’s scientific work and a complete bibliography, pp. 403–407; and Jacob Henle. Gedächtnisvortrag (Brunswick, 1909).