Abstract: A main housing assembly has a back plate and a front casing which is hingedly secured to the back plate. A bracket on the backplate supports a liquid reservoir which includes a flexible bag carried by a fiber board box, the bag having a discharge tube clamped at one corner of the bag. A discharge nozzle assembly is connected by one end to the discharge tube, the discharge nozzle assembly having a pair of ball check valves carried by the ends of a flexible tube. The lower ball check valve protrudes from the bottom of the housing when the liquid reservoir is mounted on the bracket and the nozzle assembly protrudes downwardly therefrom in front of the bracket. A depressible plunger carried by the casing is adapted to squeeze the flexible tube of the nozzle assembly so as to close the upper ball check valve and open the lower ball check valve permitting a metered amount of liquid to be discharged through the lower ball check valve.