By Eva Åhrén ~
Originally published in Hidden Treasure: The National Library of Medicine, 2011.
It was owned by Charles Darwin, Jean-Martin Charcot, Hermann von Helmholtz, and other illustrious scientists. It was displayed as a triumph of Swedish science at the Centennial Exposition in Philadelphia in 1876, along with other Swedish exhibits (such as the model schoolhouse now known as the Swedish Cottage in New York’s Central Park). Written in German, the most important scientific language of the day, the massive (42 cm.) two-volume Studien in der Anatomie des Nervensystems und des Bindegewebes (Studies in the Anatomy of the Nervous System and Connective Tissue) deals with the brain and spinal cord (particularly the covering membranes and communicative passages between the brain’s ventricles, serous spaces, and lymphatic vessels) and the nerves (their structure, sheaths, and endings).
Four men worked together closely for seven years to produce it: Axel Key (1832–1901) and Gustaf Retzius (1842–1919), and the artists Nils Otto Björkman (1833–1900) and Theodor Lundberg (1852–1926). Key was professor of pathological anatomy at the Karolinska Institute in Stockholm and later its director. A liberal public intellectual, he had studied with Rudolph Virchow in Berlin and, like other Swedish scientists, was well connected to European scientific networks. Retzius, son of the prominent comparative anatomist Anders Retzius, was beginning a productive career that would range over histology (mainly of the nervous system and sense organs), comparative anatomy, physical anthropology, popular medicine, conservative politics, and even newspaper production. Björkman was an expert scientific draftsman, known for graceful renderings of the minute details of microscopic specimens and also for ethnographic travels to Lapland, where he made drawings and collected Sámi artifacts. The young and talented Lundberg would later become a celebrated sculptor and director of the Royal Academy of Art in Stockholm.
Their project of mapping the brain was a visual exploration. First, they acquired their numerous specimens of brains and spines, most likely from the autopsied bodies of people who died in public hospitals, jails, and workhouses. Then the anatomists adapted and developed histological techniques to make the specimens reveal the desired features. They injected them with colored substances and also dipped them in acidic salt solutions of gold, silver, and osmium (the same method Camillo Golgi later used when he discovered the nerve cell).
Handling the specimens required expertise and first-rate equipment: the sharpest scalpels and microtomes for slicing the brains, the finest microscopes for examining them. The Karolinska Institute had extensive collections, and some of the specimens likely ended up there, among thousands of other microscopic slides. The artists drew the selected specimens with meticulous attention to detail, form, color, and depth. The printers then used the colored drawings to produce superb chromolithographic plates to go with the text. It was a costly book to print, in large format with superior binding and high-quality ink on fine paper, and could be completed only with support from a benefactor who donated 20,000 kronor—roughly $140,000 in today’s money. (After marrying the wealthy philanthropist Anna Hierta in 1876, Retzius never again had to depend on donations to realize his projects.) In this and other works, Retzius collaborated with the finest Swedish and German artists, photographers, and printers, although the collaborations were not always easy. Retzius eventually broke with Björkman, a superb draftsman, over stylistic matters. The artist, he believed, sacrificed accuracy in favor of aesthetics. Retzius thereafter chose to make his own drawings.
The images in these volumes are not mere illustrations of scientific findings—they are the findings. Without the image there is no scientific result. But scientific illustrations also do other work. Illustrated monographs and articles help to build personal and institutional reputations and to attract funding and students. Today’s neuroscience is just as dependent on technologies of visualization, but with computed tomography, positron emission tomography (PET), and magnetic resonance imaging (MRI) scientists can look into the brains of living people—something that would have been inconceivable to Key and Retzius.
However, the beauty of their lithographic brain images has never been surpassed.
Eva Åhrén is a Swedish historian and Operations Director the Hagströmer Medico-Historical Library, Karolinska Institutet, Sweden. She has been a Research Fellow with National Institute of Allergy and Infectious Diseases (NIAID).