Christopher Williams, Mick Peter, Evelyn De Morgan: this week’s new exhibitions

From cult photographer Christopher Williams’s first major UK survey in London to Evelyn De Morgan’s wistful paintings in Blackwell, Skye Sherwin and Robert Clark find out what’s happening in art around the countryThis exhibition’s title alludes obliquely to William Blake’s vision of seeing a world in a grain of sand. Accordingly, eight contemporary artists gather together in the modest-sized but far from small-minded International 3 gallery to show off their evocations. As the theme ca