Dutch Golden Age painting Drapers' Guild" is a subtle treatment of a group round a table. Scientists often posed with instruments and objects of their study around them. Physicians sometimes posed together around a cadaver, a so-called 'Anatomical Lesson', the most famous one being Rembrandt's "Anatomy Lesson of Dr. Nicolaes Tulp" (1632, Mauritshuis, The Hague). Boards of trustees in their "regentenstuk" portraits preferred an image of austerity and humility, posing in dark clothing (which by its refinement testified to their prominent standing in society), often seated around a table, with solemn expressions on their faces. Most militia group portraits were commissioned in Haarlem and
Nicolaes Tulp the condition we know as migraine, the devastating effects of tobacco smoking on the lungs, and reveals an understanding of human psychology in a description of the placebo effect. Tulp also discovered the ileocecal valve at the junction of the large and small intestines, still known as Tulp's valve. While Tulp made observations of various diseases, treatment often continued in the age-old way. 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. Partially as a result of the success