Not the least virtues of Dulwich's small show is the emphasis it gives to Whistler's prints. Black-and-white engravings have fallen from taste since his day but the ones here remind us how direct an artistic media etching is – and how Whistler mastered it.
His aim was to do with the London docks and river life what the Impressionists in Paris did with the new middle classes of Paris and the Seine.
He was a painter of life and mood: what the waterlily pond did for Monet, the river's reach between Chelsea and Battersea bridges did for Whistler.
The scope of the show is restricted, but the depth is profound.
020 8693 5254; dulwichpicturegallery.org.uk; to 12 January