Abstract: An apparatus (1) adapted to disseminate a volatile liquid (4), such as a fragrance, into an ambient atmosphere for a desired period of time, the apparatus comprising a reservoir (2) having a single opening (3) to the atmosphere, this opening being closed by a permeable membrane (5) not in contact with the liquid in the reservoir when the apparatus is in operation, the membrane having a thickness of from 0.1-5 mm and being capable of absorbing a quantity of liquid that will evaporate over the desired period when the membrane is brought into direct contact with the liquid. The membrane may also act as a end-of-life indicator by changing colour as the liquid is disseminated. The apparatus is an easy-to-use, spill-proof device, with the ability to control the amount of liquid in an atmosphere and to prevent habituation to the liquid.