When Count Johan Maurits (1604-1679) was governor-general of Netherlands-Brazil, he was particularly interested in the flora, fauna and culture of this beautiful country. However, he was also very concerned. Many sailors and soldiers died after contracting various tropical diseases. Something had to be done. His personal physician Willem Piso headed into the jungle with German scientist Georg Markgraf to learn about the healing properties of herbs and exotic plants. In 1648, Historia naturalis Brasiliae (Brazilian Natural History) was published. This work has proved invaluable for tropical medicine. Naturalis has a rare coloured edition in its collection. Only six coloured copies are currently available in the world.