7 Up

Brand name of the 1930s, of uncertain origin. Some theories include: * The product of 7 ingredients: sugar, carbonated water, essence of lemon and lime oils, citric acid, sodium citrate, and lithium citrate; and “Up” referring to the lithium mood lift. * Originally sold in 7-ounce bottles, unlike most other soft drinks (6oz). * Its inventor, Charles Leiper Grigg, saw cattle branded with a similar mark and drew inspiration from it. * Grigg thought of it while rooting for sevens during a game of craps. * That its pH is over 7, which is false—actually 3.79. * A coded reference to the lithium it originally contained, which has an atomic weight of around 7.

来源：wiktionary