Thungs last trip in 1960 was a visit to Braunschweig in West Germany in September 1960, to attend the fourth edition of the Conference on Potato Virus Diseases, an initiative he had launched in 1951. He was only able to witness the early days of the ‘molecular-biological revolution’ of the late 1950s. He died rather suddenly on 18 November 1960 as a result of heart problems. The last scientific publication to which he had contributed was published in May 1961. Together with his colleagues Van Kammen and Noordam, he had authored an article entitled ‘The mechanism of inhibition of infection with tobacco mosaic virus by an inhibitor from carnation sap’, which appeared in the US journal Virology.