Willem Piso (in Dutch Willem Pies, in Latin Gulielmus Piso, also called Guilherme Piso in Portuguese) (1611 in Leiden – 28 November 1678 in Amsterdam) was a Dutch physician and naturalist who participated as an expedition doctor in Dutch Brazil from 1637 – 1644, sponsored by count Johan Maurits van Nassau-Siegen and the Dutch West India Company. Piso became one of the founders of tropical medicine. Source: Wikipedia (en)