Joseph Wright of Derby - An Experiment On A Bird In The Air Pump  A travelling scientist is shown demonstrating the formation of a vacuum by withdrawing air from a flask containing a white cockatoo. Wright leaves us in doubt as to whether or not the cockatoo will be reprieved. The painting reveals a wide range of individual reactions. The figures are dramatically lit by a single candle, while in the window the moon appears. On the table in front of the candle is a glass containing a skull.