Abstract: The invention concerns apparatus, preferably a trigger-actuated portable gun, for dispensing adhesive comprising a housing containing a feed passage for receiving normally solid but heat-liquefiable adhesive block(s) having a flange for forming a fluid-tight yet yieldable seal with the feed passage, an outlet for liquefied adhesive, a coupling for connection to a source of pressurized fluid whereby in use fluid pressure is applied directly to the block(s) in the feed passage without the intermediation of a mechanical piston to advance the block(s) towards the outlet, and a heater for progressively liquefying the leading and of the block the remainder which serves as a piston for the liquefied portion thereof.