Originally Posted by wikipedia

In its simplest form, a Molotov cocktail is a glass bottle containing petrol fuel usually with a source of ignition such as a burning cloth wick held in place by the bottle's stopper.
In action the fuse is lit and the bottle hurled at a target such as a vehicle or fortification. When the bottle smashes on impact, the ensuing cloud of petrol droplets and vapor are ignited, causing an immediate fireball followed by a raging fire as the remainder of the fuel is consumed.
Other flammable liquids such as wood alcohol and turpentine have been used in place of petrol. Thickening agents such as tar, sugar, animal blood, XPS foam, egg whites, motor oil, rubber cement, and dish soap have been added to help the burning liquid adhere to the target and create clouds of thick choking smoke.