This large group portrait by Troost, his first, won instant admiration. The Collegium Medicum, consisting of physicians and apothecaries, regulated medical practice in Amsterdam. The inspectors’ names are known: standing at centre is Dr Daniël van Buuren, pointing to a new list of medicines published in Amsterdam. Seated at right is Dr Casparus Commelin, resting his hand on a catalogue of medicinal plants.