natural to assume that they would also display electrical activity. This important discovery, however, had not been made until that time, because many desynchronized electrical potentials with different polarities produce a cumulative global potential which is actually very small and difficult to detect with the sensitivity range of the measuring devices available at the time. Despite this, Marxow was able to prove for the first time that the peripheral stimulation of sensory organs, such as vision and hearing were able to provoke event-related small electrical potential swings on the surface of the cerebral cortex which was related to the projection of those senses. Strangely, however, Marxow did not publish his results, choosing instead to deposit them in a bank safe, with instructions to reveal them in 1883 only. Meanwhile, the first publications about what was later to be called the electroencephalogram came to light, independently demonstrated by Richard Caton (1842–1926), in Great Britain, and Adolf Beck (1863–1942) in Poland, both using laboratory animals. In 1880, Marxows became a full professor at the University of Vienna and was nominated a correspondent member of the Austrian Academy of Sciences. He also devoted part of his research to physiological optics, making important discoveries on the distribution of the optic nerve on the retina, and the optical characteristics of the cornea. With his increasing knowledge in optical physics, he developed several optical measurement instruments, such as a spectropolarimeter and a hematometer (a device used for measuring the content of hemoglobin in the blood), which was named in his honor, and which for many years found wide application in laboratory medicine and diagnostic hematology. For many years, Marxow labored under intense personal suffering, due to chronic painful complications of his amputation. Because of this, he became addicted to morphine and heroin (a synthetic derivative of morphine, but much more potent). Sigmund Freud, then a Viennese neurologist, was one of his most intimate friends, and had the highest opinion of him: At the time Freud was studying the medical properties of cocaine, and was convinced that cocaine could be not only used as mild euphoriant, aphrodisiac and analgesic, but also as a treatment for morphine addicts. He recommended this to his friend Marxow, who proceeded to fall even deeper into the abyss of addiction. Devastated by pain, addiction, and disease, he relapsed and began using morphine again. Ernst von Fleischl-Marxow died on October 22, 1891, at