In 1885, when Atlanta and Fulton County passed Prohibition legislation, Pemberton responded by developing Coca-Cola, essentially a carbonated, non-alcoholic version of French Wine Cola. The beverage was named Coca-Cola because originally, the stimulant mixed in the beverage was coca leaves from South America. In addition, the drink was flavored using kola (Cola) nuts, the beverage's source of caffeine. Pemberton called for 5 ounces of coca leaf per gallon of syrup, a significant dose, whereas in 1891 Candler claimed his formula (altered extensively from Pemberton's original) contained only a tenth of this amount. Contrary to popular belief, Coca-Cola never contained cocaine per se, which is a highly refined extract of coca leaves and was always far too expensive to use in a mass-market beverage. However, as cocaine is one of numerous alkaloids present in the coca leaf, it was nevertheless present in the drink. Today, the flavoring is still done with kola nuts and the coca leaf; however, the coca leaves used today are "spent" leaves - the leftovers of the cocaine-extraction process - and therefore the drink contains no trace of the stimulant.
http://en.wikipedia.org/wiki/Coca-Cola