As the population of Amsterdam grew from 30,000 in 1580 to 210,000 in 1650, Tulp's career as a doctor and politician made him a man of influence.

Thanks to his connections on the city council, in 1628 Tulp was appointed Praelector Anatomiae at the Amsterdam Guild of Surgeons.

Shocked at the exorbitant prices asked for useless anti-plague medicines (Amsterdam was severely hit by the plague in 1635), Tulp decided to do something about it.

The Apothecary guild would require an exam based on Tulp's book for new chemists to set up shop in Amsterdam.

Throughout Europe, these dissections were attended by prominent learned men, who exchanged ideas about anatomy and the chemical processes of the human body.

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.

[citation needed] Rembrandt's event depicted in the painting can be dated to 16 January 1632; the Amsterdam Guild of Surgeons, of which Tulp was official City Anatomist, permitted only one public dissection a year and the body would have to be that of an executed criminal.

Since the painting of Tulp's predecessor in 1619, The Osteology Lesson of Dr. Sebastiaen Egbertsz was a group portrait around a skeleton, it is clear that the subject of a dead body had set a precedent.

Some called it the "book of monsters" because Tulp dissected animals brought back from the Dutch East India Company's ships, but also because of the fantastic stories that he relates.

An example; Jan de Doot, a blacksmith in Amsterdam, was in such pain from a bladder stone, that he sharpened a knife and removed it himself because he refused to be the victim of the 'stone cutters'.

His description of the symptoms of Beriberi in a Dutch seaman, for example, went unnoticed until the cause (vitamin B1 deficiency) was recognized two hundred years later by Christiaan Eijkman.

In 1655 Tulp's daughter Margaretha married Jan Six, whom he helped become a magistrate of family affairs in Amsterdam.