Re Jonathan Jones’s review of the Joseph Wright of Derby exhibition at the National Gallery, and his 1768 painting An Experiment on a Bird in the Air Pump (Wright of Derby: From the Shadows review – science, skeletons and a suffocated cockatoo, 4 November), the good news is that the bird probably doesn’t die after all.

An episode of Radio 4’s Moving Pictures, broadcast in February, told us that the air pump resembles those produced in this period by Benjamin Martin, which were supplied with instructions for experiments to try at home.

One of these was to put a live animal inside the air pump, extract the air and then, at the last moment, turn a stopcock to restore the air and revive the animal. You could thus amaze your friends and family by apparently killing a creature and then restoring it to life.

The programme suggested that this might be why all but the youngest members of the family seem so unconcerned – they already know the plot. Still, not much fun for the bird.
Harriet Monkhouse
Manchester