Karl Landsteiner ("tuberculinum prestinum"). He also published a number of papers, five of them being published in Dutch by the Royal Academy of Sciences. Yet working conditions proved to be not much better than in post-war Vienna. So Landsteiner accepted the invitation that reached him from New York, initiated by Simon Flexner, who was familiar with Landsteiner's work, to work for the Rockefeller Institute. He arrived there with his family in the spring of 1923. Throughout the 1920s Landsteiner worked on the problems of immunity and allergy. In 1927 he discovered new blood groups: M, N and P, refining the work he
Karl Landsteiner he published 75 papers, dealing with issues in serology, bacteriology, virology and pathological anatomy. In addition he did some 3,600 autopsies in those ten years. Weichselbaum was Landsteiner's tutor for his postdoctoral lecture qualification in 1903. From 1908 to 1920 Landsteiner was prosector at the Wilhelminenspital in Vienna and in 1911 he was sworn in as an associate professor of pathological anatomy. During that time he discovered – in co-operation with Erwin Popper – the infectious character of poliomyelitis and isolated the polio virus. In recognition of this groundbreaking discovery, which proved to be the basis for the fight against