An Experiment on a Bird in the Air Pump

A travelling natural philosopher demonstrates the air pump to a middle-class family. The white cockatoo in the glass jar will die when the air is pumped out — a standard 18th- century demonstration of the necessity of air for life. Wright caught the moment the philosopher decides whether to let it die: he stares at us, hand on the valve. The older girl looks away in tears; the boy peers in fascinated; moonlight comes through the window. Now at National Gallery, London @nationalgallery