Eau de Cologne , or simply cologne, is a perfume originating from Cologne, Germany. Originally mixed by Italian-born Johann Maria Farina in 1709, it has since come to be a generic term for scented formulations in typical concentration of 2%–5% and also more depending upon its type essential oils or a blend of extracts, alcohol, and water. In a base of dilute ethanol (70%–90%), eau de cologne contains a mixture of citrus oils including oils of lemon, orange, tangerine, clementine, bergamot, lime, grapefruit, blood orange, and bitter orange. It can also contain oils of neroli, lavender, rosemary, thyme, oregano, petitgrain (orange leaf), jasmine, olive, oleaster, and tobacco. (source)