Effervescence

Effervescence means the escape of gas in bubbles from a mass of liquid in which it has been compelled to remain by pressure. Effervescence will take place when the pressure is removed, as when the cork is removed from a bottle of sodawater. The same discharge of bubbles may occur when, by reason of some change in the liquid, it is unable to retain the gas. Thus ordinary water effervesces a little when heated, because hot water eloes not hold air so readily as cold. The action is more vigorous in the case of ammoniated water.