The present invention is directed to a device for releasing a controlled amount of a volatile substance into an environment while isolating the non-released amount of such a substance from the environment. The device includes a housing having an interior region, a volatile substance cartridge associated with the housing, wherein the cartridge can be replaced, or, alternatively, refilled with a desired fluid. A mechanism is provided for releasing a pre-determined amount of fluid from the housing, which is activated, as desired, by a user of the device.