ozone [M19th] Today the usual association of ozone is with the ozone layer [1920s], a layer in the earth’s stratosphere that absorbs most of the harmful ultraviolet radiation reaching the earth from the sun, and which is under threat from atmospheric pollutants. Ozone is a strong-smelling, poisonous form of oxygen whose name goes back to Greek ozein ‘to smell’. It was originally believed to have a tonic effect and to be present in fresh air, especially at the seaside. In Penelope Mortimer’s autobiographical About Time (1987) she writes: ‘An important part of our middle-class Englishness was the seaside holiday—no baking on a Mediterranean beach, but lungfuls of ozone, gales, hard sand.’