Cornelia Parker on Turner

Turner was a master of capturing the intangible in paint, increasingly pushing his subjects to the point of vaporisation, pulling them back from the brink only when they threatened to disappear. How he must have loved the moody London fogs, with their uncertain atmospheres blurring the borders between solid and void.

Or the Venetian mists, with their water particles suffused with incandescent light. Or the physicality of a snowstorm, where liquid becomes unyielding, sky becomes sea and land becomes sky. He revelled in those situations, where recognisable detail was only achieved by a fleeting intensity of focus, as if it were an apparition.