Teyler's Foundation in Haarlem and its 'Book and Art Room' of 1779, edited by Ellinoor Bergvelt and Debora Meijers, examines for the first time this institution in the context of scientific, museological, political, artistic, religious and philosophical developments. The key moment was the decision in 1779 to give a free interpretation to the testament of its founder, the Mennonite entrepreneur Pieter Teyler van der Hulst (1702-1778): stimulated by the naturalist Martinus van Marum, the Foundation's board decided to build an impressive museum room and to establish a natural science collection. The institution thus entered an era in which older scientific and collecting traditions engaged with new developments towards a research institution and a public museum of natural history, physics and art. Contributors: Ellinoor S. Bergvelt, Terry van Druten, Arnold Heumakers, Eric Jorink, Paul Knolle, Debora Meijers, Wijnand Mijnhardt, Bert Sliggers, Koenraad Vos, and Holger Zaunstock.