Ozone

Sharp, dry and cool-metallic, like the clear air right after a thunderstorm.

• In the 19th century, ozone was thought to be what made sea and mountain air healthy; the typical smell of the sea, however, comes mainly from dimethyl sulphide and compounds produced by seaweed.

Ozone consists of three oxygen atoms (O₃); the chemist Christian Friedrich Schönbein named it in 1840 after the Greek ozein, “to smell”, because he first recognised the gas by its odour.