Nicolaes Tulp attended by prominent learned men, who exchanged ideas about anatomy and the chemical processes of the human body. As befits a new praelector, the Guild commissioned a new group portrait of the prominent councilmen and guildmasters. Rembrandt, himself a young man of 26 and new to the city, won this commission and made a famous painting of him: "The Anatomy Lesson of Dr Nicolaes Tulp". This painting, which now hangs in the Mauritshuis museum of the Hague, depicts Tulp dissecting such a criminal's forearm. There has been much speculation as to why the dissection began on the forearm. Rembrandt's event
Observationes Medicae (Tulp) popular, that a hundred years later a translated version was published. Professor Tulp never wanted to publish in Dutch for fear of hypochondriac behavior. He was very against quacks and self-medication and it was for this reason that he worked on the Amsterdam Pharmacopoeia. This second version therefore, would have been against his wishes. However, the book was prefaced by a long "lykoratie", or ode to his memory, in which Ludovicus Wolzogen explains what a wonderful man Tulp was, and everything that he did for the city of Amsterdam and medicine in general. He claims to have made an accurate