Rembrandt "Danaë", 1636), seeking to emulate the baroque style of Rubens. With the occasional help of assistants in Uylenburgh's workshop, he painted numerous portrait commissions both small ("Jacob de Gheyn III") and large ("Portrait of the Shipbuilder Jan Rijcksen and his Wife", 1633, "Anatomy Lesson of Dr. Nicolaes Tulp", 1632). By the late 1630s Rembrandt had produced a few paintings and many etchings of landscapes. Often these landscapes highlighted natural drama, featuring uprooted trees and ominous skies ("Cottages before a Stormy Sky", c. 1641; "The Three Trees", 1643). From 1640 his work became less exuberant and more sober in tone, possibly
Nicolaes Tulp an enormous amount of herbs and spices from the East, thanks to the new shipping routes. It became a successful trade and in 1636 there were 66 apothecaries in Amsterdam. Shocked at the exorbitant prices asked for useless anti-plague medicines (Amsterdam was severely hit by the plague in 1635), Dr Tulp decided to do something about it. He gathered his doctor and chemist friends together and they wrote the first pharmacopoeia of Amsterdam in 1636 the "Pharmacopoea Amstelredamensis". The Apothecary guild would require an exam based on Dr Tulp's book in order for new chemists to set up shop in