The Salt-Water Jars

A university physiology room in Edinburgh on a snowy January afternoon, on a long red-brown wooden table a string galvanometer of black lacquered tubes and blocks on a grey granite slab between two broad magnet coils covered in wine-red leather, brass knurled screws and a round lens on a swinging arm, at the left end a tall wooden camera tower, a black switch panel with knobs along the table front, three white porcelain jars of clear salt water beside an empty wooden armchair with a grey blanket over its arm, a hand in a white coat sleeve setting a brass screw, low snow light and the glow of a coal fire.