These nine photographs form part of the artist’s project The Recovery of Dissolved Substances. It also includes sketches and a wooden structure encrusted with salt. Onwin’s work explores the chemistry, natural history and life cycle of salt, first inspired by visiting a tidal saltmarsh near Dunbar, East Lothian, Scotland in 1973. The photographs’ grid format echoes the cubic structure of salt crystals. They document sections of an underground salt room, made by the artist in an undisclosed location somewhere in Edinburgh. This mysterious room has only been seen by one or two people.