for the extended period of time such as one month for example required to exhaust the contents of reservoir housing 70 the additive motor 68 is connected through an electrical cable 88 to a soap dispensing control means comprised of a rotatable knob 90 protruding from a control panel 92 which extends upwardly from a marginal portion of access end wall 20 adjacent rear wall 17 of cabinet 12 knob 90 may be maintained at a zero rotational position and pressed axially inward toward panel 92 for electrically energizing motor 68 and activating pump 66 as long as the knob 90 is pressed inwardly toward panel 92 alternatively the knob 90 may be rotated such as ninety degrees from the zero rotational positions for example to select a predetermined quantity of additive liquid soap 72 such as one quarter of a cup for example then the knob 90 may be pressed inwardly toward panel 92 and released to energize motor 68 and activate pump 66 for a predetermined length of time in either instance when the pump 66 is activated liquid soap 72 is drawn from the reservoir housing 70 through hose 71 and forced through the hose 64 to the delivery tube component 60 of.