Abstract: An apparatus for controllably releasing a substance is disclosed herein. In one embodiment, such an apparatus includes a chamber to store a non-gaseous fluid. An outlet communicates with a bottom of the chamber to dispense the non-gaseous fluid. An inlet communicates with a top of the chamber to enable gas to flow into the chamber. To regulate the flow of non-gaseous fluid through the outlet, a regulator element is coupled to the inlet to regulate the flow of gas into the chamber. In certain embodiments, to provide more consistent release rates, the chamber includes a short wide portion situated above a relatively long narrow portion. Such a configuration generates more consistent head pressure and thus more consistent release rates for the non-gaseous fluid. A corresponding method is also disclosed herein.