Joseph Wright of Derby

Experiment on a Bird in the Air Pump

Oil on canvas, 183 × 244 cm, 1768
This painting pictures a ‘travelling scientist’ (quite a common thing in the 18th century) display how an air pump works to what looks like a family. There is a bird in a glass container (an at the time rare cockatoo which was probably never used for such deadly experiments). The air has been slowly removed from the container and the  onlookers can see the effect on the poor bird. The fact that there is a boy on the right holding a bird cage ready, suggests that the scientist is not planning on letting it die, but it does underline the cruelty of such experiments.
Although Wright has painted scientific experiments as well as portraits of scientists,  the painting is most interesting in how it shows a rich array of human emotions as well as its exquisite use of light. The faces of the characters vary from aghast to concentrated, scared, fascinated and simply elsewhere ( the couple on the left clearly have more eyes for each other than the experiment). They are as archetypes of human emotion. The scientist himself is dressed in flamboyant red gown and is looking at us directly.
The lighting in the work is exquisite and dramatic. The bright light source (a lamp perhaps)  is hidden behind the container on the table. Wright really showed off how well he could paint dramatic light (called chiaroscuro ) from a difficult angle. Some faces have the light coming from the side, such as the little girl, while others are against the light (the dark figure on the left) and the scientist himself is lit from below. The whole thing is a tour de force in chiaroscuro. And it is the light and shade which gives the whole piece its wonderfully dramatic and theatrical mood.
National Gallery

The painting is on loan from the National Gallery to the RWA in Bristol and on show in the exhibition Air until 3 September