Image and Imagination of the Life Sciences : The Stereomicroscope on the Cusp of Modern Biology

The Greenough stereomicroscope, or "Stemi" as it is colloquially known among microscopists, is a stereoscopic binocular instrument yielding three-dimensional depth perception when working with larger microscopic specimens. It has become ubiquitous in laboratory practice since its introduction by the unknown scientist Horatio Saltonstall Greenough in 1892. However, because it enabled new experimental practices rather than new knowledge, it has largely eluded historical and epistemological investigation, even though its design, production, and reception in the scientific community was inextricably connected to the new epistemological ideals of the life sciences caught between natural history and modern science. The development of the microscope will be contextualized within the scientific and technological landscape, showing how Greenough navigated his way through this terrain, and what led him to sow the seeds for the stereoscopic microscope. The historical controversy over the optical mechanism, through which the instrument would generate the desired depth perception, and how this quality was embedded into laboratory practice, will be examined. Subsequently, it will become evident that the specific image of nature produced by the stereoscopic microscope corresponded to the new ideals of the life sciences and their representation.