The use of ether in medicine is one of the dimensions that Christoph Keller addresses in his exhibition “Small Survey on Nothingness.” The lecture by Professor Thomas Schnalke casts a wider eye on the discipline of medicine around 1850. Like few other eras in the history of medicine, this period was marked by radical changes at all levels. In the lab, but also at the patient’s bedside, a rational-scientific view was taking hold. To distinguish itself from the idea of the vital forces, the focus was now on Biochemistry and body mechanics, specific sensory energies and “animal electricity,” cells, tissues and organs. Overnight, sulfuric ether became the symbolic substance of a whole era. Gaseous and colorless in appearance and thus absolutely “nothing” – or so it seemed –, ether’s material presence produced effects that both doctors and patients previously could only have dreamed of. It was now possible to relieve patients of pain and make them unconscious in a controlled manner. Enormous possibilities opened up to surgeons. At the same time, they worried that something would get lost …