Portrait painting benefitted greatly from such commissions and from the general appreciation of art by bourgeois clients, who supported portraiture as well as still-life and landscapes painting. In addition, the first significant art and dealer markets flourished in Holland at that time. With plenty of demand, Rembrandt was able to experiment with unconventional composition and technique, such as chiaroscuro. He demonstrated these innovations, pioneered by Italian masters such as Caravaggio, most notably in his famous "Night Watch" (1642). "The Anatomy Lesson of Dr. Tulp" (1632) is another fine example of Rembrandt's mastery of the group painting, in which he bathes the corpse
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